PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (1362678)

Clipboard (0)
None

Related Articles

1.  Hounsfield units upon PET/CT are useful in evaluating metastatic regional lymph nodes in patients with oesophageal squamous cell carcinoma 
The British Journal of Radiology  2012;85(1013):606-612.
Objectives
This study evaluated the usefulness of measurements of X-ray attenuation (in Hounsfield units) obtained from unenhanced CT images for attenuation correction of the positron emission tomography (PET) data from PET/CT in the assessment of regional lymph node metastasis in oesophageal squamous cell carcinoma.
Methods
17 patients with oesophageal squamous cell carcinoma underwent surgery after evaluation with PET/CT. After the excised lymph nodes were reviewed, we compared the histopathology and PET/CT findings, and analysed the lymph node metastasis. When 18-F fludeoxyglucose (FDG) uptake in the lymph nodes was focally prominent in comparison with background mediastinal activity (regardless of lymph node size), the lymph nodes were considered to be positive for malignancy by PET/CT. The mean Hounsfield units of mediastinal lymph nodes showing abnormally increased FDG uptake in PET/CT was retrospectively evaluated using images from the unenhanced CT component of PET/CT. Receiver operating characteristic (ROC) curve analysis was applied to determine the optimal cut-off value of mean Hounsfield units for detecting individual lymph node metastases.
Results
For depiction of malignant nodal groups in each lymph node group, the sensitivity, specificity and accuracy of PET/CT based on increased FDG uptake were 58.8%, 74.5% and 70.8%, respectively. For patients with nodal groups that were positive for uptake by PET/CT, the mean attenuation in lymph nodes as measured by CT was 48±13 HU for malignant nodes and 75±18 HU for benign nodes. This difference was statistically significant (p<0.001). Using ROC curve analysis, we determined the cut-off as 71 HU. When we excluded lymph nodes with attenuation higher than 71 HU from the nodes determined as malignant by PET/CT, the specificity and accuracy for detecting metastatic lymph nodes improved to 90.9% and 83.3%, respectively.
Conclusions
When interpreting lymph node metastasis in oesophageal squamous cell carcinoma using PET/CT, the assumption that any lymph node with mean HU>71 is benign can improve diagnostic accuracy.
doi:10.1259/bjr/73516936
PMCID: PMC3479874  PMID: 21304006
2.  Utility of 18F-fluoro-deoxyglucose emission tomography/computed tomography fusion imaging (18F-FDG PET/CT) in combination with ultrasonography for axillary staging in primary breast cancer 
BMC Cancer  2008;8:165.
Background
Accurate evaluation of axillary lymph node (ALN) involvement is mandatory before treatment of primary breast cancer. The aim of this study is to compare preoperative diagnostic accuracy between positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (18F-FDG PET/CT) and axillary ultrasonography (AUS) for detecting ALN metastasis in patients having operable breast cancer, and to assess the clinical management of axillary 18F-FDG PET/CT for therapeutic indication of sentinel node biopsy (SNB) and preoperative systemic chemotherapy (PSC).
Methods
One hundred eighty-three patients with primary operable breast cancer were recruited. All patients underwent 18F-FDG PET/CT and AUS followed by SNB and/or ALN dissection (ALND). Using 18F-FDG PET/CT, we studied both a visual assessment of 18F-FDG uptake and standardized uptake value (SUV) for axillary staging.
Results
In a visual assessment of 18F-FDG PET/CT, the diagnostic accuracy of ALN metastasis was 83% with 58% in sensitivity and 95% in specificity, and when cut-off point of SUV was set at 1.8, sensitivity, specificity, and accuracy were 36, 100, and 79%, respectively. On the other hand, the diagnostic accuracy of AUS was 85% with 54% in sensitivity and 99% in specificity. By the combination of 18F-FDG PET/CT and AUS to the axilla, the sensitivity, specificity, and accuracy were 64, 94, and 85%, respectively. If either 18F-FDG PET uptake or AUS was positive in allixa, the probability of axillary metastasis was high; 50% (6 of 12) in 18F-FDG PET uptake only, 80% (4 of 5) in AUS positive only, and 100% (28 of 28) in dual positive. By the combination of AUS and 18F-FDG PET/CT, candidates of SNB were more appropriately selected. The axillary 18F-FDG uptake was correlated with the maximum size and nuclear grade of metastatic foci (p = 0.006 and p = 0.03).
Conclusion
The diagnostic accuracy of 18F-FDG PET/CT was shown to be nearly equal to ultrasound, and considering their limited sensitivities, the high radiation exposure by 18F-FDG PET/CT and also costs of the examination, it is likely that AUS will be more cost-effective in detecting massive axillary tumor burden. However, when we cannot judge the axillary staging using AUS alone, metabolic approach of 18F-FDG PET/CT for axillary staging would enable us a much more confident diagnosis.
doi:10.1186/1471-2407-8-165
PMCID: PMC2430574  PMID: 18541009
3.  Semiquantitative analysis of maximum standardized uptake values of regional lymph nodes in inflammatory breast cancer: Is there a reliable threshold for differentiating benign from malignant? 
Academic radiology  2012;19(5):535-541.
Rationale and Objectives
Our objective is to determine an optimum standardized uptake value (SUV) threshold for identifying regional nodal metastasis on 18 fluoro-deoxy-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) studies of patients with inflammatory breast cancer (IBC).
Materials and Methods
A database search was performed of newly diagnosed IBC patients who had 18F-FDG PET/CT performed at the time of diagnosis in a single institution between January 1, 2001 and September 30, 2009. Three radiologists blinded to the histopathology of the regional lymph nodes retrospectively analyzed all 18F-FDG PET/CT images by measuring the SUVmax in visually abnormal nodes. The accuracy of 18F-FDG PET/CT image interpretation was correlated with histopathology where available. A receiver operating characteristic curve (ROC) analysis was performed to assess the diagnostic performance of PET/CT. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated using 3 different SUV cutoff values (2.0, 2.5, 3.0).
Results
A total of 888 regional nodal basins, including bilateral axillary, infraclavicular, internal mammary and supraclavicular lymph nodes were evaluated in 111 patients with a mean age of 56 years. Of the 888 nodal basins, 625 (70%) were negative and 263 (30%) were positive for metastasis. Malignant lymph nodes had significantly higher SUVmax than benign lymph nodes (p <0.0001). An SUVmax of 2.0 showed the highest overall sensitivity (89%) and specificity (99%) for the diagnosis of malignant disease.
Conclusion
SUVmax of regional lymph nodes on 18F-FDG PET/CT may help differentiate benign and malignant lymph nodes in IBC patients. SUV cutoff 2 provided the best accuracy in identifying regional nodal metastasis in this patient population.
doi:10.1016/j.acra.2012.01.001
PMCID: PMC4128395  PMID: 22300741
4.  Maximum standardized uptake value on PET/CT in preoperative assessment of lymph node metastasis from thoracic esophageal squamous cell carcinoma 
Chinese Journal of Cancer  2014;33(4):211-217.
The presence of lymph node metastasis is an important prognostic factor for patients with esophageal cancer. Accurate assessment of lymph nodes in thoracic esophageal carcinoma is essential for selecting appropriate treatment and forecasting disease progression. Positron emission tomography combined with computed tomography (PET/CT) is becoming an important tool in the workup of esophageal carcinoma. Here, we evaluated the effectiveness of the maximum standardized uptake value (SUVmax) in assessing lymph node metastasis in esophageal squamous cell carcinoma (ESCC) prior to surgery. Fifty-nine surgical patients with pathologically confirmed thoracic ESCC were retrospectively studied. These patients underwent radical esophagectomy with pathologic evaluation of lymph nodes. They all had 18F-FDG PET/CT scans in their preoperative staging procedures. None had a prior history of cancer. The pathologic status and PET/CT SUVmax of lymph nodes were collected to calculate the receiver operating characteristic (ROC) curve and to determine the best cutoff value of the PET/CT SUVmax to distinguish benign from malignant lymph nodes. Lymph node data from 27 others were used for the validation. A total of 323 lymph nodes including 39 metastatic lymph nodes were evaluated in the training cohort, and 117 lymph nodes including 32 metastatic lymph nodes were evaluated in the validation cohort. The cutoff point of the SUVmax for lymph nodes was 4.1, as calculated by ROC curve (sensitivity, 80%; specificity, 92%; accuracy, 90%). When this cutoff value was applied to the validation cohort, a sensitivity, a specificity, and an accuracy of 81%, 88%, and 86%, respectively, were obtained. These results suggest that the SUVmax of lymph nodes predicts malignancy. Indeed, when an SUVmax of 4.1 was used instead of 2.5, FDG-PET/CT was more accurate in assessing nodal metastasis.
doi:10.5732/cjc.013.10039
PMCID: PMC3975187  PMID: 24559853
SUVmax; esophageal squamous cell carcinoma; cutoff value; esophagectomy; lymph nodes
5.  The Accuracy of Integrated [18F] Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography in Detection of Pelvic and Para-aortic Nodal Metastasis in Patients with High Risk Endometrial Cancer 
World Journal of Nuclear Medicine  2014;13(3):170-177.
Lymph nodal (LN) metastasis is the most important prognostic factor in high-risk endometrial cancer. However, the benefit of routine lymphadenectomy in endometrial cancer is controversial. This study was conducted to assess the accuracy of [18F] fluorodeoxyglucose-positron emission tomography/computed tomography ([18F] FDG-PET/CT) in detection of pelvic and para-aortic nodal metastases in high-risk endometrial cancer. 20 patients with high-risk endometrial carcinoma underwent [18F] FDG-PET/CT followed by total abdominal hysterectomy, bilateral salpingo-oophorectomy and systematic pelvic lymphadenectomy with or without para-aortic lymphadenectomy. The findings on histopathology were compared with [18F] FDG-PET/CT findings to calculate the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of [18F] FDG-PET/CT. The pelvic nodal findings were analyzed on a patient and nodal chain based criteria. The para-aortic nodal findings were reported separately. Histopathology documented nodal involvement in two patients (10%). For detection of pelvic nodes, on a patient based analysis, [18F] FDG-PET/CT had a sensitivity of 100%, specificity of 61.11%, PPV of 22.22%, NPV of 100% and accuracy of 65% and on a nodal chain based analysis, [18F] FDG-PET/CT had a sensitivity of 100%, specificity of 80%, PPV of 20%, NPV of 100%, and accuracy of 80.95%. For detection of para-aortic nodes, [18F] FDG-PET/CT had sensitivity of 100%, specificity of 66.67%, PPV of 20%, NPV of 100%, and accuracy of 69.23%. Although [18F] FDG-PET/CT has high sensitivity for detection of LN metastasis in endometrial carcinoma, it had moderate accuracy and high false positivity. However, the high NPV is important in selecting patients in whom lymphadenectomy may be omitted.
doi:10.4103/1450-1147.144817
PMCID: PMC4262875  PMID: 25538488
[18F] Fluorodeoxyglucose-positron emission tomography/computed tomography; endometrial cancer; high risk; lymphadenectomy; preoperative imaging
6.  Diagnostic Value of EBUS-TBNA for Lung Cancer with Non-Enlarged Lymph Nodes: A Study in a Tuberculosis-Endemic Country 
PLoS ONE  2011;6(2):e16877.
Background
In tuberculosis (TB)-endemic areas, contrast-enhanced computed tomography (CT) and positron emission tomography (PET) findings of lung cancer patients with non-enlarged lymph nodes are frequently discrepant. Endobronchial ultrasound-guided transbronchial aspiration (EBUS-TBNA) enables real-time nodal sampling, and thereby improves nodal diagnosis accuracy. This study aimed to compare the accuracy of nodal diagnosis by using EBUS-TBNA, and PET.
Methods
We studied 43 lung cancer patients with CT-defined non-enlarged mediastinal and hilar lymph nodes and examined 78 lymph nodes using EBUS-TBNA.
Results
The sensitivity, specificity, positive predictive value, and negative predictive value of EBUS-TBNA were 80.6%, 100%, 100%, and 85.7%, respectively. PET had low specificity (18.9%) and a low positive predictive value (44.4%). The diagnostic accuracy of EBUS-TBNA was higher than that of PET (91% vs. 47.4%; p<0.001). Compared to CT-based nodal assessment, PET yielded a positive diagnostic impact in 36.9% nodes, a negative diagnostic impact in 46.2% nodes, and no diagnostic impact in 16.9% nodes. Patients with lymph nodes showing negative PET diagnostic impact had a high incidence of previous pulmonary TB. Multivariate analysis indicated that detection of hilar nodes on PET was an independent predictor of negative diagnostic impact of PET.
Conclusion
In a TB-endemic area with a condition of CT-defined non-enlarged lymph node, the negative diagnostic impact of PET limits its clinical usefulness for nodal staging; therefore, EBUS-TBNA, which facilitates direct diagnosis, is preferred.
doi:10.1371/journal.pone.0016877
PMCID: PMC3045379  PMID: 21364919
7.  Paraaortic lymph node metastasis in patients with intra-abdominal malignancies: CT vs PET 
AIM: To compare the diagnostic accuracy of computed tomography (CT) and positron emission tomography (PET) for the preoperative detection of paraaortic lymph node (PAN) metastasis in patients with intra-abdominal malignancies.
METHODS: Sixty-six patients with intra-abdominal malignancies who underwent both CT and PET before lymphadenectomy were included in this study. Histopathologically, 13 patients had metastatic PAN, while 53 had non-metastatic PAN. The CT criteria for metastasis were: short diameter of > 8 mm, lobular or irregular shape, and/or combined ancillary findings, including necrosis, conglomeration, vessel encasement, and infiltration. The PET criterion was positive fluorodeoxyglucose (FDG) uptake. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of both modalities were compared with the pathologic findings, and the false positive and false negative cases with both CT and PET were analyzed.
RESULTS: The sensitivity, specificity, PPV, NPV, and accuracy of CT were 61.5%, 84.9%, 50%, 90% and 80.3%, respectively. For PET, the percentages were 46.2%, 100%, 100%, 88.3%, and 89.4%. Additionally, there were 8 false positive CT cases (8/53, 15.1%) and zero false positive PET cases. Of the 13 metastatic PANs, there were 5 false negative CT scans (38.5%) and 7 (53.9%) false negative PET scans.
CONCLUSION: For detecting PAN metastasis, CT is more sensitive than PET, while PET is more specific.
doi:10.3748/wjg.15.4434
PMCID: PMC2747065  PMID: 19764096
Malignancy; Paraaortic lymph node; Computed tomography; Positron emission tomography; Sensitivity; Specificity
8.  Role of FDG-PET scans in staging, response assessment, and follow-up care for non-small cell lung cancer 
Frontiers in Oncology  2013;2:208.
The integral role of positron-emission tomography (PET) using the glucose analog tracer fluorine-18 fluorodeoxyglucose (FDG) in the staging of non-small cell lung cancer (NSCLC) is well established. Evidence is emerging for the role of PET in response assessment to neoadjuvant therapy, combined-modality therapy, and early detection of recurrence. Here, we review the current literature on these aspects of PET in the management of NSCLC. FDG-PET, particularly integrated 18F-FDG-PET/CT, scans have become a standard test in the staging of local tumor extent, mediastinal lymph node involvement, and distant metastatic disease in NSCLC. 18F-FDG-PET sensitivity is generally superior to computed tomography (CT) scans alone. Local tumor extent and T stage can be more accurately determined with FDG-PET in certain cases, especially in areas of post-obstructive atelectasis or low CT density variation. FDG-PET sensitivity is decreased in tumors <1 cm, at least in part due to respiratory motion. False-negative results can occur in areas of low tumor burden, e.g., small lymph nodes or ground-glass opacities. 18F-FDG-PET-CT nodal staging is more accurate than CT alone, as hilar and mediastinal involvement is often detected first on 18F-FDG-PET scan when CT criteria for malignant involvement are not met. 18F-FDG-PET scans have widely replaced bone scintography for assessing distant metastases, except for the brain, which still warrants dedicated brain imaging. 18F-FDG uptake has also been shown to vary between histologies, with adenocarcinomas generally being less FDG avid than squamous cell carcinomas. 18F-FDG-PET scans are useful to detect recurrences, but are currently not recommended for routine follow-up. Typically, patients are followed with chest CT scans every 3–6 months, using 18F-FDG-PET to evaluate equivocal CT findings. As high 18F-FDG uptake can occur in infectious, inflammatory, and other non-neoplastic conditions, 18F-FDG-PET-positive findings require pathological confirmation in most cases. There is increased interest in the prognostic and predictive role of FDG-PET scans. Studies show that absence of metabolic response to neoadjuvant therapy correlates with poor pathologic response, and a favorable 18F-FDG-PET response appears to be associated with improved survival. Further work is underway to identify subsets of patients that might benefit individualized management based on FDG-PET.
doi:10.3389/fonc.2012.00208
PMCID: PMC3539654  PMID: 23316478
PET; non-small cell lung cancer; staging; response assessment; follow-up
9.  Staging the axilla in breast cancer patients with 18F-FDG PET: how small are the metastases that we can detect with new generation clinical PET systems? 
Purpose
Point spread function (PSF) reconstruction improves spatial resolution throughout the entire field of view of a PET system and can detect smaller metastatic deposits than conventional algorithms such as OSEM. We assessed the impact of PSF reconstruction on quantitative values and diagnostic accuracy for axillary staging of breast cancer patients, compared with an OSEM reconstruction, with emphasis on the size of nodal metastases.
Methods
This was a prospective study in a single referral centre in which 50 patients underwent an 18F-FDG PET examination before axillary lymph node dissection. PET data were reconstructed with an OSEM algorithm and PSF reconstruction, analysed blindly and validated by a pathologist who measured the largest nodal metastasis per axilla. This size was used to evaluate PET diagnostic performance.
Results
On pathology, 34 patients (68 %) had nodal involvement. Overall, the median size of the largest nodal metastasis per axilla was 7 mm (range 0.5 – 40 mm). PSF reconstruction detected more involved nodes than OSEM reconstruction (p = 0.003). The mean PSF to OSEM SUVmax ratio was 1.66 (95 % CI 1.01 – 2.32). The sensitivities of PSF and OSEM reconstructions were, respectively, 96 % and 92 % in patients with a largest nodal metastasis of >7 mm, 60 % and 40 % in patients with a largest nodal metastasis of ≤7 mm, and 92 % and 69 % in patients with a primary tumour ≤30 mm. Biggerstaff graphical comparison showed that globally PSF reconstruction was superior to OSEM reconstruction. The median sizes of the largest nodal metastasis in patients with nodal involvement not detected by either PSF or OSEM reconstruction, detected by PSF but not by OSEM reconstruction and detected by both reconstructions were 3, 6 and 16 mm (p = 0.0064) respectively. In patients with nodal involvement detected by PSF reconstruction but not by OSEM reconstruction, the smallest detectable metastasis was 1.8 mm.
Conclusion
As a result of better activity recovery, PET with PSF reconstruction performed better than PET with OSEM reconstruction in detecting nodal metastases ≤7 mm. However, its sensitivity is still insufficient for it to replace surgical approaches for axillary staging. PET with PSF reconstruction could be used to perform sentinel node biopsy more safely in patients with a primary tumour ≤30 mm and with unremarkable PET results in the axilla.
Electronic supplementary material
The online version of this article (doi:10.1007/s00259-014-2689-7) contains supplementary material, which is available to authorized users.
doi:10.1007/s00259-014-2689-7
PMCID: PMC4006125  PMID: 24562642
PET/CT; Breast cancer; Axillary staging; Fluorodeoxyglucose; PSF reconstruction
10.  Staging of neuroendocrine tumours: comparison of [68Ga]DOTATOC multiphase PET/CT and whole-body MRI 
Cancer Imaging  2013;13(1):63-72.
Abstract
Purpose: In patients with a neuroendocrine tumour (NET), the extent of disease strongly influences the outcome and multidisciplinary therapeutic management. Thus, systematic analysis of the diagnostic performance of the existing staging modalities is necessary. The aim of this study was to compare the diagnostic performance of 2 whole-body imaging modalities, [68Ga]DOTATOC positron emission tomography (PET)/computed tomography (CT) and magnetic resonance imaging (MRI) in patients with NET with regard to possible impact on treatment decisions. Materials and methods: [68Ga]DOTATOC-PET/CT and whole-body magnetic resonance imaging (wbMRI) were performed on 51 patients (25 females, 26 males, mean age 57 years) with histologically proven NET and suspicion of metastatic spread within a mean interval of 2.4 days (range 0–28 days). PET/CT was performed after intravenous administration of 150 MBq [68Ga]DOTATOC. The CT protocol comprised multiphase contrast-enhanced imaging. The MRI protocol consisted of standard sequences before and after intravenous contrast administration at 1.5 T. Each modality (PET, CT, PET/CT, wbMRI) was evaluated independently by 2 experienced readers. Consensus decision based on correlation of all imaging data, histologic and surgical findings and clinical follow-up was established as the standard of reference. Lesion-based and patient-based analysis was performed. Detection rates and accuracy were compared using the McNemar test. P values <0.05 were considered significant. The impact of whole-body imaging on the treatment decision was evaluated by the interdisciplinary tumour board of our institution. Results: 593 metastatic lesions were detected in 41 of 51 (80%) patients with NET (lung 54, liver 266, bone 131, lymph node 99, other 43). One hundred and twenty PET-negative lesions were detected by CT or MRI. Of all 593 lesions detected, PET identified 381 (64%) true-positive lesions, CT 482 (81%), PET/CT 545 (92%) and wbMRI 540 (91%). Comparison of lesion-based detection rates between PET/CT and wbMRI revealed significantly higher sensitivity of PET/CT for metastatic lymph nodes (100% vs 73%; P < 0.0001) and pulmonary lesions (100% vs 87%; P = 0.0233), whereas wbMRI had significantly higher detection rates for liver (99% vs 92%; P < 0.0001) and bone lesions (96% vs 82%; P < 0.0001). Of all 593 lesions, 22 were found only in PET, 11 only in CT and 47 only in wbMRI. The patient-based overall assessment of the metastatic status of the patient showed comparable sensitivity of PET/CT and MRI with slightly higher accuracy of PET/CT. Patient-based analysis of metastatic organ involvement revealed significantly higher accuracy of PET/CT for bone and lymph node metastases (100% vs 88%; P = 0.0412 and 98% vs 78%; P = 0.0044) and for the overall comparison (99% vs 89%; P < 0.0001). The imaging results influenced the treatment decision in 30 patients (59%) with comparable information from PET/CT and wbMRI in 30 patients, additional relevant information from PET/CT in 16 patients and from wbMRI in 7 patients. Conclusion: PET/CT and wbMRI showed comparable overall lesion-based detection rates for metastatic involvement in NET but significantly differed in organ-based detection rates with superiority of PET/CT for lymph node and pulmonary lesions and of wbMRI for liver and bone metastases. Patient-based analysis revealed superiority of PET/CT for NET staging. Individual treatment strategies benefit from complementary information from PET/CT and MRI.
doi:10.1102/1470-7330.2013.0007
PMCID: PMC3589947  PMID: 23466785
Neuroendocrine tumours; staging; PET/CT; [68Ga]DOTATOC; magnetic resonance imaging
11.  A pilot study of 4′-[methyl-11C]-thiothymidine PET/CT for detection of regional lymph node metastasis in non-small cell lung cancer 
EJNMMI Research  2014;4:10.
Background
4′-[methyl-11C]-thiothymidine (4DST) is a novel positron emission tomography (PET) tracer to assess proliferation of malignancy. The diagnostic abilities of 4DST and 2-deoxy-2-18 F-fluoro-d-glucose (FDG) for detecting regional lymph node (LN) metastases of non-small cell lung cancer (NSCLC) were prospectively compared. In addition, the relationship between the PET result and the patient's prognosis was evaluated.
Methods
A total of 31 patients with NSCLC underwent 4DST PET/computed tomography (CT) and FDG PET/CT. The PET/CT images were evaluated qualitatively and quantitatively for focal uptake of each PET tracer, according to the staging system of the American Joint Committee on Cancer. Surgical and histological results provided the reference standards. Patients were followed for up to two years to assess disease-free survival.
Results
On a per-lesion basis, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for LN staging were 82%, 72%, 32%, 96%, and 73%, respectively, for 4DST, and 29%, 86%, 25%, 88%, and 78%, respectively, for FDG. The sensitivity of 4DST was significantly higher than that of FDG (P < 0.001). The disease-free survival rate with positive 4DST uptake in nodal lesions was 0.35, which was considerably lower than the rate of 0.83 with negative findings (P = 0.04). Among the factors tested, nodal staging by 4DST was the most influential prognostic factor (P = 0.05) in predicting the presence of a previously existing spread lesion or of a recurrence over the course of 2 years.
Conclusion
4DST PET/CT is sensitive for detecting mediastinal lymph node metastasis in NSCLC, but its low specificity is a limitation. However, it may be helpful in predicting the prognosis of NSCLC.
doi:10.1186/2191-219X-4-10
PMCID: PMC3976537  PMID: 24593883
4DST; FDG-PET/CT; Lymph node metastasis; Non-small cell lung cancer (NSCLC); Cell proliferation
12.  Positron Emission Tomography for the Assessment of Myocardial Viability 
Executive Summary
Objective
The objective was to update the 2001 systematic review conducted by the Institute For Clinical Evaluative Sciences (ICES) on the use of positron emission tomography (PET) in assessing myocardial viability. The update consisted of a review and analysis of the research evidence published since the 2001 ICES review to determine the effectiveness and cost-effectiveness of PET in detecting left ventricular (LV) viability and predicting patient outcomes after revascularization in comparison with other noninvasive techniques.
Background
Left Ventricular Viability
Heart failure is a complex syndrome that impairs the contractile ability of the heart to maintain adequate blood circulation, resulting in poor functional capacity and increased risk of morbidity and mortality. It is the leading cause of hospitalization in elderly Canadians. In more than two-thirds of cases, heart failure is secondary to coronary heart disease. It has been shown that dysfunctional myocardium resulting from coronary heart disease (CAD) may recover contractile function (i.e. considered viable). Dysfunctional but viable myocardium may have been stunned by a brief episode of ischemia, followed by restoration of perfusion, and may regain function spontaneously. It is believed that repetitive stunning results in hibernating myocardium that will only regain contractile function upon revascularization.
For people with CAD and severe LV dysfunction (left ventricular ejection fraction [LVEF] <35%) refractory to medical therapy, coronary artery bypass and heart transplantation are the only treatment options. The opportunity for a heart transplant is limited by scarcityof donor hearts. Coronary artery bypass in these patients is associated with high perioperative complications; however, there is evidence that revascularization in the presence of dysfunctional but viable myocardium is associated with survival benefits and lower rates of cardiac events. The assessment of left ventricular (LV) viability is, therefore, critical in deciding whether a patient with coronary artery disease and severe LV dysfunction should undergo revascularization, receive a heart transplant, or remain on medical therapy.
Assessment of Left Ventricular Viability
Techniques for assessing myocardial viability depend on the measurement of a specific characteristic of viable myocytes such as cell membrane integrity, preserved metabolism, mitochondria integrity, and preserved contractile reserve. In Ontario, single photon emission computed tomography (SPECT) using radioactive 201thallium is the most commonly used technique followed by dobutamine echocardiography. Newer techniques include SPECT using technetium tracers, cardiac magnetic resonance imaging, and PET, the subject of this review.
Positron Emission Tomography
PET is a nuclear imaging technique based on the metabolism of radioactive analogs of normal substrates such as glucose and water. The radiopharmaceutical used most frequently in myocardial viability assessment is F18 fluorodeoxyglucose (FDG), a glucose analog. The procedure involves the intravenous administration of FDG under controlled glycemic conditions, and imaging with a PET scanner. The images are reconstructed using computer software and analyzed visually or semi-quantitatively, often in conjunction with perfusion images. Dysfunctional but stunned myocardium is characterized by normal perfusion and normal FDG uptake; hibernating myocardium exhibits reduced perfusion and normal/enhanced FDG uptake (perfusion/metabolism mismatch), whereas scar tissue is characterized by reduction in both perfusion and FDG uptake (perfusion/metabolism match).
Review Strategy
The Medical Advisory Secretariat used a search strategy similar to that used in the 2001 ICES review to identify English language reports of health technology assessments and primary studies in selected databases, published from January 1, 2001 to April 20, 2005. Patients of interest were those with CAD and severe ventricular dysfunction being considered for revascularization that had undergone viability assessment using either PET and/or other noninvasive techniques. The outcomes of interest were diagnostic and predictive accuracy with respect to recovery of regional or global LV function, long-term survival and cardiac events, and quality of life. Other outcomes of interest were impact on treatment decision, adverse events, and cost-effectiveness ratios.
Of 456 citations, 8 systematic reviews/meta-analyses and 37 reports on primary studies met the selection criteria. The reports were categorized using the Medical Advisory Secretariat levels of evidence system, and the quality of the reports was assessed using the criteria of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) developed by the Centre for Dissemination of Research (National Health Service, United Kingdom). Analysis of sensitivity, specificity, predictive values and likelihood ratios were conducted for all data as well as stratified by mean left ventricular ejection fraction (LVEF). There were no randomized controlled trials. The included studies compared PET with one or more other noninvasive viability tests on the same group of patients or examined the long-term outcomes of PET viability assessments. The quality assessment showed that about 50% or more of the studies had selection bias, interpreted tests without blinding, excluded uninterpretable segments in the analysis, or did not have clearly stated selection criteria. Data from the above studies were integrated with data from the 2001 ICES review for analysis and interpretation.
Summary of Findings
The evidence was derived from populations with moderate to severe ischemic LV dysfunction with an overall quality that ranges from moderate to low.
PET appears to be a safe technique for assessing myocardial viability.
CAD patients with moderate to severe ischemic LV dysfunction and residual viable myocardium had significantly lower 2-year mortality rate (3.2%) and higher event-free survival rates (92% at 3 years) when treated with revascularization than those who were not revascularized but were treated medically (16% mortality at 2-years and 48% 3-year event-free survival).
A large meta-analysis and moderate quality studies of diagnostic accuracy consistently showed that compared to other noninvasive diagnostic tests such as thallium SPECT and echocardiography, FDG PET has:
Higher sensitivity (median 90%, range 71%–100%) and better negative likelihood ratio (median 0.16, range 0–0.38; ideal <0.1) for predicting regional myocardial function recovery after revascularization.
Specificity (median 73%, range 33%–91%) that is similar to other radionuclide imaging but lower than that of dobutamine echocardiography
Less useful positive likelihood ratio (median 3.1, range 1.4 –9.2; ideal>10) for predicting segmental function recovery.
Taking positive and negative likelihood ratios together suggests that FDG PET and dobutamine echocardiography may produce small but sometimes important changes in the probability of recovering regional wall motion after revascularization.
Given its higher sensitivity, PET is less likely to produce false positive results in myocardial viability. PET, therefore, has the potential to identify some patients who might benefit from revascularization, but who would not have been identified as suitable candidates for revascularization using thallium SPECT or dobutamine echocardiography.
PET appears to be superior to other nuclear imaging techniques including SPECT with 201thallium or technetium labelled tracers, although recent studies suggest that FDG SPECT may have comparable diagnostic accuracy as FDG PET for predicting regional and global LV function recovery.
No firm conclusion can be reached about the incremental value of PET over other noninvasive techniques for predicting global function improvement or long-term outcomes in the most important target population (patients with severe ischemic LV dysfunction) due to lack of direct comparison.
An Ontario-based economic analysis showed that in people with CAD and severe LV dysfunction and who were found to have no viable myocardium or indeterminate results by thallium SPECT, the use of PET as a follow-up assessment would likely result in lower cost and better 5-year survival compared to the use of thallium SPECT alone. The projected annual budget impact of adding PET under the above scenario was estimated to range from $1.5 million to $2.3 million.
Conclusion
In patients with severe LV dysfunction, that are deemed to have no viable myocardium or indeterminate results in assessments using other noninvasive tests, PET may have a role in further identifying patients who may benefit from revascularization. No firm conclusion can be drawn on the impact of PET viability assessment on long-term clinical outcomes in the most important target population (i.e. patients with severe LV dysfunction).
PMCID: PMC3385418  PMID: 23074467
13.  Implications of False Negative and False Positive Diagnosis in Lymph Node Staging of NSCLC by Means of 18F-FDG PET/CT 
PLoS ONE  2013;8(10):e78552.
Background
Integrated 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is widely performed in hilar and mediastinal lymph node (HMLN) staging of non-small cell lung cancer (NSCLC). However, the diagnostic efficiency of PET/CT remains controversial. This retrospective study is to evaluate the accuracy of PET/CT and the characteristics of false negatives and false positives to improve specificity and sensitivity.
Methods
219 NSCLC patients with systematic lymph node dissection or sampling underwent preoperative PET/CT scan. Nodal uptake with a maximum standardized uptake value (SUVmax) >2.5 was interpreted as PET/CT positive. The results of PET/CT were compared with the histopathological findings. The receiver operating characteristic (ROC) curve was generated to determine the diagnostic efficiency of PET/CT. Univariate and multivariate analysis were conducted to detect risk factors of false negatives and false positives.
Results
The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/ CT in detecting HMLN metastases were 74.2% (49/66), 73.2% (112/153), 54.4% (49/90), 86.8% (112/129), and 73.5% (161/219). The ROC curve had an area under curve (AUC) of 0.791 (95% CI 0.723-0.860). The incidence of false negative HMLN metastases was 13.2% (17 of 129 patients). Factors that are significantly associated with false negatives are: concurrent lung disease or diabetes (p<0.001), non-adenocarcinoma (p<0.001), and SUVmax of primary tumor >4.0 (p=0.009). Postoperatively, 45.5% (41/90) patients were confirmed as false positive cases. The univariate analysis indicated age > 65 years old (p=0.009), well differentiation (p=0.002), and SUVmax of primary tumor ≦4.0 (p=0.007) as risk factors for false positive uptake.
Conclusion
The SUVmax of HMLN is a predictor of malignancy. Lymph node staging using PET/CT is far from equal to pathological staging account of some risk factors. This study may provide some aids to pre-therapy evaluation and decision-making.
doi:10.1371/journal.pone.0078552
PMCID: PMC3808350  PMID: 24205256
14.  Role of Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Diagnostic Evaluation of Carcinoma Urinary Bladder: Comparison with Computed Tomography 
Bladder carcinoma is the most frequent tumor of the urinary tract and accounts 7% of all malignancies in men and 2% of all malignancies in women. This retrospective study was carried out to assess the diagnostic utility of F18-fludeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the imaging evaluation of bladder carcinoma. Seventy-seven consecutive patients diagnosed to have carcinoma urinary bladder referred for F18-FDG PET/CT were included in this study. Thirty-four patients were for initial staging after transurethral biopsy and remaining 43 patients were for restaging. All patients also underwent CT scan of the abdomen and pelvis. PET/CT findings were correlated with diagnostic CT scan and histopathological findings. In 30 of the 34 patients for initial staging, both PET/CT and CT confirmed the primary lesion in the bladder. Histopathology report was available in 23 patients. Lymph nodes FDG uptake reported to be metastatic in 10/23 patients while CT detected lymph node metastasis in 12 patients. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy have been calculated to be 87.5%, 80%, 70%, 92%, 82% for PET/CT and 66%, 57%, 50%, 72%, 60% for CT respectively. PET/CT detected metastatic disease in 8 patients whereas CT detected in 4 patients. Of the 43 patients for restaging, local recurrence was detected in 24 patients on both PET/CT and CT. Histopathology report was available in 17 patients. Sensitivity, specificity, PPV, NPV and accuracy were 85%, 60%, 60%, 85%, 70% for PET/CT and 80%, 50%, 40%, 85%, 58% for CT respectively. Nineteen patients were detected to have metastatic disease by PET/CT, whereas CT detected metastases in 11 patients. F-18 FDG PET/CT is a very useful modality in pre-operative staging and monitoring after surgery, chemotherapy or radiotherapy of patients with carcinoma urinary bladder.
doi:10.4103/1450-1147.138572
PMCID: PMC4149767  PMID: 25191110
Bladder carcinoma; fludeoxyglucose positron emission tomography/computed tomography; restaging; staging
15.  The Value of F-18 FDG PET for Planning Treatment and Detecting Recurrence in Malignant Salivary Gland Tumors: Comparison with Conventional Imaging Studies 
Purpose
To assess the value of F-18 FDG PET/CT for detecting cervical lymph node (LN) metastasis and recurrence, as well as planning treatment, and to compare the accuracy of PET/CT with conventional imaging studies (CIS) in patients with malignant salivary gland tumor (SGT).
Methods
Staging and follow-up PET/CT for SGT were retrospectively reviewed. Enhanced CT and/or MRI of the neck were performed within 1 month of PET/CT. Final diagnosis was based on histology from cervical LN dissection and biopsy or a minimum 6 months of clinical and imaging follow-up. We compared the performance of PET/CT in initial cervical LN staging and recurrence detection with that of CIS.
Results
A total of 184 PET/CT exams of 66 patients were included, and 34 initial staging and 150 surveillance PET/CT exams were performed. The initial cervical LN detection sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 60.9 %, 89.2 %, 84.0 %, 56.0 %, and 91.0 % for visual analysis on PET/CT, 39.1 %, 95.0 %, 84.8 %, 64.3 %, and 87.4 % for semiquantitative analysis on PET/CT, and and 43.5 %, 94.1 %, 84.8 %, 62.5 %, and 88.1 % for CIS. The sensitivity of visual analysis on PET/CT was significantly higher than that of semiquantitative analysis on PET/CT and CIS (p = 0.0009 and 0.0086). In 5 of 34 initial staging patients (14.7 %), the treatment plan was changed from curative surgery to palliative therapy. The performance of follow-up PET/CT showed no significant difference compared with CIS.
Conclusion
PET/CT showed comparable performance with CIS for cervical LNs staging. Initial PET/CT changed treatment plans in 14.7 % of patients. However, PET/CT offered no additional advantage for detecting locoregional recurrence.
doi:10.1007/s13139-013-0222-8
PMCID: PMC4035178  PMID: 24900119
Salivary gland neoplasm; F-18 FDG PET/CT; Cervical lymph nodes; Staging
16.  Value of fusion of PET and MRI in the detection of intra-pelvic recurrence of gynecological tumor: comparison with 18F-FDG contrast-enhanced PET/CT and pelvic MRI 
Annals of Nuclear Medicine  2013;28(1):25-32.
Background
To evaluate the diagnostic value of retrospective image fusion from pelvic magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography (PET) in detecting intra-pelvic recurrence of gynecological tumor.
Methods
Thirty patients with a suspicion of recurrence of gynecological malignancy underwent inline contrast-enhanced PET/computed tomography (CT) and pelvic contrast-enhanced MRI for restaging. Diagnostic performance about the local recurrence, pelvic lymph node and bone metastasis and peritoneal lesion of PET/low-dose non-enhanced CT (PET/ldCT), PET/full-dose contrast-enhanced CT (PET/ceCT), contrast-enhanced MRI, and retrospective image fusion from PET and MRI (fused PET/MRI) were evaluated by two experienced readers. Final diagnoses were obtained by histopathological examinations, radiological imaging and clinical follow-up for at least 6 months. McNemar test was employed for statistical analysis.
Results
Documented positive locally recurrent disease, pelvic lymph node and bone metastases, and peritoneal dissemination were present in 53.3, 26.7, 10.0, and 16.7 %, respectively. Patient-based sensitivity for detecting local recurrence, pelvic lymph node and bone metastasis and peritoneal lesion were 87.5, 87.5, 100 and 80.0 %, respectively, for fused PET/MRI, 87.5, 62.5, 66.7 and 60.0 %, respectively, for contrast-enhanced MRI, 62.5, 87.5, 66.7 and 80.0 %, respectively, for PET/ceCT, and 50.0, 87.5, 66.7 and 60.0 %, respectively, for PET/ldCT. The sensitivity of diagnosing local recurrence by fused PET/MRI was significantly better than that of PET/ldCT (p = 0.041). The patient-based sensitivity, specificity and accuracy for the detection of intra-pelvic recurrence/metastasis were 91.3, 100 and 93.3 % for fused PET/MRI, 82.6, 100 and 86.7 % for contrast-enhanced MRI, 82.6, 100 and 86.7 % for PET/ceCT and 78.3, 85.7 and 80.0 % for PET/ldCT.
Conclusion
Fused PET/MRI combines the individual advantages of MRI and PET, and is a valuable technique for assessment of intra-pelvic recurrence of gynecological cancers.
doi:10.1007/s12149-013-0777-6
PMCID: PMC4328133  PMID: 24129541
Fused PET/MRI; PET/CT; MRI; Restaging; Gynecological tumor
17.  Lymph node staging in non-small cell lung cancer: evaluation by [18F]FDG positron emission tomography (PET) 
Thorax  1997;52(5):438-441.
BACKGROUND: A study was undertaken to investigate the accuracy of positron emission tomography (PET) with 2-[18F]-fluoro-2-deoxy-D- glucose (FDG) in the thoracic lymph node staging of non-small cell lung cancer (NSCLC). METHODS: Forty six patients with focal pulmonary tumours who underwent preoperative computed tomographic (CT) and FDG- PET scanning were evaluated retrospectively. Thirty two patients had NSCLC and 14 patients had a benign process. The final diagnosis was established by means of histopathological examination at thoracotomy, and the nodal classification in patients with lung cancer was performed by thorough dissection of the mediastinal nodes at surgery. RESULTS: FDG-PET was 80% sensitive, 100% specific, and 87.5% accurate in staging thoracic lymph nodes in patients with NSCLC, whereas CT scanning was 50% sensitive, 75% specific, and 59.4% accurate. The absence of lymph node tumour involvement was identified by FDG-PET in all 12 patients with NO disease compared with nine by CT scanning. Lymph node metastases were correctly detected by FDG-PET in three of five patients with N1 disease compared with two by CT scanning, in nine of 11 with N2 disease compared with six by CT scanning, an in all four with N3 nodes compared with two by CT scanning. CONCLUSIONS: FDG-PET provides a new and effective method for staging thoracic lymph nodes in patients with lung cancer and is superior to CT scanning in the assessment of hilar and mediastinal nodal metastases. With regard to resectability, FDG-PET could differentiate reliably between patients with N1/N2 disease and those with unresectable N3 disease. 



PMCID: PMC1758560  PMID: 9176535
18.  Comparison of PET-CT and Conventional Imaging in Staging Pediatric Rhabdomyosarcoma 
Pediatric blood & cancer  2012;60(7):1128-1134.
Purpose
To compare PET-CT to conventional imaging (CI) in staging pediatric rhabdomyosarcoma (RMS).
Subjects and Methods
Thirty subjects with RMS, median age 7.3 years, underwent PET-CT before therapy. PET-CTs and CI were independently reviewed by two radiologists and two nuclear medicine physician to determine the presence of nodal, pulmonary, bone, bone marrow and other sites of metastasis. Accuracy, sensitivity and specificity of PET-CT for detecting metastases was compared to CI using biopsy and clinical follow-up as reference standards. Maximum standardized uptake values (SUVmax) of primary tumors, lymph nodes and pulmonary nodules were measured.
Results
Primary tumors had an average SUVmax of 7.2 (range, 2.5-19.2). Accuracy rates for 17 subjects with nodal disease were 95% for PET-CT and 49% for CI. PET-CT had 94% sensitivity and 100% specificity for nodal disease. Of 7 pulmonary nodules detected by CI, 3 were not identified by PET-CT, 2 were indeterminate by PET-CT, and 1 was malignant with a SUVmax (3.4) > twice that of benign nodules. Two subjects had bone disease; both were identified by PET-CT but only 1 by CI. Four subjects had bone marrow disease, 2 had positive PET-CTs but none had positive CI. Two subjects had soft tissue metastases detected by PET-CT but not CI.
Conclusion
PET-CT performed better than CI in identifying nodal, bone, bone marrow, and soft tissue disease in children with RMS. CI remains essential for detection of pulmonary nodules. We recommend PET-CT for routine staging of children with RMS. CI with Tc99m bone scan can be eliminated.
doi:10.1002/pbc.24430
PMCID: PMC4266929  PMID: 23255260
19.  FDG-PET-based Prognostic Nomograms for Locally Advanced Cervical Cancer 
Gynecologic oncology  2012;127(1):136-140.
Purpose:
Patients with cervical cancer of the same clinical FIGO stage can have distinctly different outcomes. We previously found that several individual factors determined by positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG), including primary cervical tumor maximum standardized uptake value (SUVmax), cervical tumor volume, and highest level of lymph node (LN) involvement, provide prognostic information about patient outcome. For this study, we aimed to evaluate the combined prognostic value of these three factors assessed on pretreatment FDG-PET for recurrence-free survival (RFS), disease-specific survival (DSS), and overall survival (OS).
Patients and Methods:
The study included 482 cervical cancer patients, FIGO stage Ia2-IVa, treated with definitive radiation or chemoradiation therapy. All patients underwent FDG-PET or FDG-PET/CT at diagnosis, from which cervical tumor volume, LN status, and tumor SUVmax were recorded. Using these PET-based factors, prognostic nomograms based on Cox regression were created for RFS, DSS, and OS. The prediction accuracies of the nomograms were measured using the concordance index (c-statistic).
Results:
Fifty-seven percent of patients had FDG-avid lymph nodes on PET; the highest level of nodal involvement was pelvic in 186, para-aortic in 65, and supraclavicular in 26. The average cervix tumor SUVmax was 11.8 (range, 2.0–50.4). PET tumor volume ranged from 3.0 to 535.7 cm3 (average, 65.2 cm3). The median follow-up was 57.5 months for patients alive at the time of last follow-up. PET LN status had the greatest influence on outcome and SUVmax was the second most important factor for all 3 endpoints. The c-statistics for the 3 nomograms were 0.756 for RFS, 0.733 for DSS, and 0.649 for OS.
Conclusions:
Pretreatment FDG-PET LN status, cervical tumor SUVmax, and PET tumor volume combined in a nomogram create good models for cervical cancer RFS, DSS, and OS.
doi:10.1016/j.ygyno.2012.06.027
PMCID: PMC3991305  PMID: 22735785
FDG-PET; lymph node; prognosis; cervix; nomogram
20.  Role and interpretation of FDG-PET/CT in HIV patients with fever of unknown origin: a prospective study 
Purpose of the study
Fever of unknown origin (FUO) is a challenging clinical entity in HIV patients. FDG-PET/CT is well validated in the work-up of FUO in HIV-negative patients but in HIV viremic patients, metabolism of HIV reactive lymph nodes could decrease its specificity. We prospectively evaluated the usefulness of FDG-PET/CT in FUO in HIV-positive patients and in particular whether HIV viremia impacts on FDG-PET/CT performance.
Methods
FDG-PET/CT was performed in 20 HIV patients with FUO and compared with FDG-PET/CT in 10 HIV viremic patients without FUO. Final diagnosis for FUO was based on histopathology, microbiology, or clinical and imaging follow-up. Mode of diagnosis, accordance of FDG-PET/CT with final diagnosis, localization of invasive diagnosis procedures was recorded in order to assess usefulness of FDG-PET/CT.
Results
FDG-PET/CT showed a different pattern in FUO and asymptomatic viremic patients. Reactive HIV lymph nodes in asymptomatic viremic patients were mostly peripheral with mean SUVmax of 6.5. In patients with FUO and underlying focal pathologies, hypermetabolic lymph nodes were central with mean SUVmax of 11.6. Presence of central lymph nodes with high FDG uptake in had a 100% specificity for focal pathology, even in viremic patients and absence of these had 100% negative predictive value. Lymph node biopsy in central hypermetabolic areas allowed identifying underlying disease in all FUO patients. For peripheral lymph nodes, a ROC curve was built in order to define the best cut-off of SUVmax for biopsy: SUVmax of 6–8 showed a sensitivity of 62.5% and specificity of 75%. Lymph nodes with SUVmax<4 had sensitivity of 0%.
Conclusions
FDG-PET/CT contributed to the diagnosis or exclusion of a focal etiology of the febrile state in 80% of HIV patients with FUO. Although number of patients was small, we could highlight several clear-cut features to help interpreting FDG-PET/CT in HIV patients with FUO. As in HIV-negative patients, we showed the usefulness of FDG-PET/CT in FUO in HIV patients even if they are viremic.
doi:10.7448/IAS.15.6.18107
PMCID: PMC3512434
21.  Usefulness of Integrated PET/MRI in Head and Neck Cancer: A Preliminary Study 
Purpose
The new modality of an integrated positron emission tomography/magnetic resonance imaging (PET/MRI) has recently been introduced but not validated. Our objective was to evaluate clinical performance of 18F-fluoro-2-deoxyglucose (18F-FDG) PET/MRI in patients with head and neck cancer.
Methods
This retrospective study was conducted between January 2013 and February 2013. Ten patients (eight men, two women; mean age, 61.4 ± 13.4 years) with histologically proven head and neck tumors were enrolled. Whole-body PET/MRI and regional positron emission tomography (PET) with dedicated MRI were sequentially obtained. Maximum standardized uptake value (SUVmax), SUVmean, metabolic tumor volume, total lesion glycolysis and contrast enhancement were analyzed. A total of ten whole-body positron emission tomography (PET), ten regional positron emission tomography (PET), ten dedicated MRI and ten regional PET/gadolinium-enhanced T1-weighted (Gd)-MRI images were analyzed for initial staging. Two nuclear medicine physicians analyzed positron emission tomography (PET) and PET/MRI with a consensus. One radiologist analyzed dedicated MRI. The primary lesions and number of metastatic lymph nodes analyzed from each image were compared.
Results
Eight patients were diagnosed with head and neck cancer (one tongue cancer, four tonsillar cancers, one nasopharyngeal cancer and two hypopharyngeal cancers) by histological diagnosis. Two benign tumors (pleomorphic adenoma and Warthin tumor) were diagnosed with surgical operation. Whole-body positron emission tomography (PET) and regional positron emission tomography (PET) attenuated by MRI showed good image quality for the lesion detection. Whole-body positron emission tomography (PET) and regional positron emission tomography (PET) detected ten primary sites and compensated for a missed lesion on dedicated MRI. A discordant number of suspicious lymph node metastases was noted according to the different images; 22, 16, 39 and 40 in the whole-body positron emission tomography (PET) only, dedicated MR, regional positron emission tomography (PET) only and regional PET/Gd-MRI, respectively. There was no distant metastasis based on analysis of whole-body positron emission tomography (PET) and whole-body PET/Dixon-volume interpolated breathhold examination (VIBE) MRI. Regional PET/Gd-MRI combined with whole-body PET/MRI modified staging in three patients. Lesions of primary tumor and suspicious metastasis were well detected on both value of SUVmax and visual analysis. The regional PET/Gd-MRI combined with whole-body PET/MRI showed convenient clinical staging performance compared with positron emission tomography (PET) and MRI alone.
Conclusion
In this preliminary study, PET attenuated by MRI showed good image quality to detect lesions. And whole-body PET/MRI as a single modality was feasible for staging in a clinical setting. Whole-body positron emission tomography (PET), regional positron emission tomography (PET), dedicated MRI and regional PET/Gd-MRI showed discordant results in lesion detection. These discordant results might be synergistic effect for accurate staging.
doi:10.1007/s13139-013-0252-2
PMCID: PMC4028474  PMID: 24900149
Head and neck cancer; Oncology; PET; MRI; Integrated PET/MRI
22.  Usefulness of Integrated PET/MRI in Head and Neck Cancer: A Preliminary Study 
Purpose
The new modality of an integrated positron emission tomography/magnetic resonance imaging (PET/MRI) has recently been introduced but not validated. Our objective was to evaluate clinical performance of 18F-fluoro-2-deoxyglucose (18F-FDG) PET/MRI in patients with head and neck cancer.
Methods
This retrospective study was conducted between January 2013 and February 2013. Ten patients (eight men, two women; mean age, 61.4 ± 13.4 years) with histologically proven head and neck tumors were enrolled. Whole-body PET/MRI and regional positron emission tomography (PET) with dedicated MRI were sequentially obtained. Maximum standardized uptake value (SUVmax), SUVmean, metabolic tumor volume, total lesion glycolysis and contrast enhancement were analyzed. A total of ten whole-body positron emission tomography (PET), ten regional positron emission tomography (PET), ten dedicated MRI and ten regional PET/gadolinium-enhanced T1-weighted (Gd)-MRI images were analyzed for initial staging. Two nuclear medicine physicians analyzed positron emission tomography (PET) and PET/MRI with a consensus. One radiologist analyzed dedicated MRI. The primary lesions and number of metastatic lymph nodes analyzed from each image were compared.
Results
Eight patients were diagnosed with head and neck cancer (one tongue cancer, four tonsillar cancers, one nasopharyngeal cancer and two hypopharyngeal cancers) by histological diagnosis. Two benign tumors (pleomorphic adenoma and Warthin tumor) were diagnosed with surgical operation. Whole-body positron emission tomography (PET) and regional positron emission tomography (PET) attenuated by MRI showed good image quality for the lesion detection. Whole-body positron emission tomography (PET) and regional positron emission tomography (PET) detected ten primary sites and compensated for a missed lesion on dedicated MRI. A discordant number of suspicious lymph node metastases was noted according to the different images; 22, 16, 39 and 40 in the whole-body positron emission tomography (PET) only, dedicated MR, regional positron emission tomography (PET) only and regional PET/Gd-MRI, respectively. There was no distant metastasis based on analysis of whole-body positron emission tomography (PET) and whole-body PET/Dixon-volume interpolated breathhold examination (VIBE) MRI. Regional PET/Gd-MRI combined with whole-body PET/MRI modified staging in three patients. Lesions of primary tumor and suspicious metastasis were well detected on both value of SUVmax and visual analysis. The regional PET/Gd-MRI combined with whole-body PET/MRI showed convenient clinical staging performance compared with positron emission tomography (PET) and MRI alone.
Conclusion
In this preliminary study, PET attenuated by MRI showed good image quality to detect lesions. And whole-body PET/MRI as a single modality was feasible for staging in a clinical setting. Whole-body positron emission tomography (PET), regional positron emission tomography (PET), dedicated MRI and regional PET/Gd-MRI showed discordant results in lesion detection. These discordant results might be synergistic effect for accurate staging.
doi:10.1007/s13139-013-0252-2
PMCID: PMC4028474  PMID: 24900149
Head and neck cancer; Oncology; PET; MRI; Integrated PET/MRI
23.  Integrated FDG‐PET/CT does not make invasive staging of the intrathoracic lymph nodes in non‐small cell lung cancer redundant: a prospective study 
Thorax  2007;62(8):696-701.
Background
Staging of non‐small cell lung cancer (NSCLC) is important for determining choice of treatment and prognosis. The accuracy of FDG‐PET scans for staging of lymph nodes is too low to replace invasive nodal staging. It is unknown whether the accuracy of integrated FDG‐PET/CT scanning makes invasive staging redundant.
Methods
In a prospective study, the mediastinal and/or hilar lymph nodes in patients with proven NSCLC were investigated with integrated FDG‐PET/CT scanning. Pathological confirmation of all suspect lymph nodes was obtained to calculate the accuracy of the fusion images. In addition, the use of the standardised uptake value (SUV) in the staging of intrathoracic lymph nodes was analysed.
Results
105 intrathoracic lymph node stations from 52 patients with NSCLC were characterised. The prevalence of malignancy in the lymph nodes was 36%. The sensitivity of the integrated FDG‐PET/CT scan to detect malignant lymph nodes was 84% and its specificity was 85% (positive likelihood ratio 5.64, negative likelihood ratio 0.19). SUVmax, SUVmean and the SUVmax/SUVliver ratio were all significantly higher in malignant than in benign lymph nodes. The area under the receiver operating curve did not differ between these three quantitative variables, but the highest accuracy was found with the SUVmax/SUVliver ratio. At a cut‐off value of 1.5 for the SUVmax/SUVliver ratio, the sensitivity and specificity to detect malignant lymph node invasion were 82% and 93%, respectively.
Conclusion
The accuracy of integrated FDG‐PET/CT scanning is too low to replace invasive intrathoracic lymph node staging in patients with NSCLC. The visual interpretation of the fusion images of the integrated FDG‐PET/CT scan can be replaced by the quantitative variable SUVmax/SUVliver without loss of accuracy for intrathoracic lymph node staging.
doi:10.1136/thx.2006.072959
PMCID: PMC2117288  PMID: 17687098
24.  Factors Associated with Positive F-18 Flurodeoxyglucose Positron Emission Tomography Before Thyroidectomy in Patients with Papillary Thyroid Carcinoma 
Thyroid  2012;22(7):725-729.
Background
The role for pre-thyroidectomy (pre-Tx) imaging with F-18 flurodeoxyglucose (FDG) positron emission tomography (PET), FDG PET–computed tomography (CT), in differentiated thyroid cancer is controversial as is the significance of positive and negative FDG uptake in this setting. We reviewed the records of patients with papillary thyroid carcinoma (PTC) who had pre-Tx FDG PET-CT to determine whether FDG uptake was associated with features noted on pre-Tx ultrasonography (US) and parameters determined after post-Tx.
Methods
Patients were selected for a retrospective review of their records if they had a total Tx with central lymph node dissection for PTC and pre-Tx FDG PET-CT and US between 2006 and 2009. Sixty patients who met these criteria were studied. Patients who had a history of head and neck irradiation, surgery, or sclerotherapy with ethanol in the last 3 months were excluded. The clinicopathologic factors—age, sex, size, tumor–node–metastasis (TNM) staging, the presence of extrathyroidal extention, multifocality, cervical lymph node metastases (CLNM), Hashimoto thyroiditis, and US characteristics—were evaluated to determine whether they were associated with positive pre-Tx FDG uptake.
Results
Forty-three (71.6%) of patients in the study had positive FDG uptake. Larger tumors and the presence of CLNM were associated with a greater likelihood of positive FDG uptake. The sensitivity, specificity, positive predictive value, and negative predictive value for CLNM detection by FDG PET-CT showed low statistical values. When considering the excellence of US for evaluating a thyroid nodule size and the presence of CLNM, the clinical value of pre-Tx FDG PET-CT is comparatively limited.
Conclusion
Pre-Tx FDG PET is not recommended for routine use in patients with PTC.
doi:10.1089/thy.2011.0031
PMCID: PMC3387768  PMID: 22524470
25.  The Role of 18F-FDG PET/CT in the Evaluation of Gastric Cancer Recurrence after Curative Gastrectomy 
Yonsei Medical Journal  2010;52(1):81-88.
Purpose
18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scans are frequently performed for the screening or staging of malignant tumors. This study aimed to assess the usefulness of 18F-FDG PET/CT in detection of gastric cancer recurrence after curative gastrectomy.
Materials and Methods
Eighty nine patients who had undergone curative gastrectomy due to gastric cancer and had 18F-FDG PET/CT and contrast CT scans within 2 weeks for surveillance in asymptomatic patients (n = 11) or to clarify suspected recurrence (n = 78) were consecutively collected and retrospectively analyzed. They had clinical follow-up for at least 12 months after PET/CT and CT scans.
Results
Fifteen of the 89 patients (16.9%) were diagnosed with recurrent gastric cancer in 21 organs. Forty one organs showed an increase in FDG uptake, and only 9 of these organs were diagnosed with recurrent gastric cancer by 18F-FDG PET/CT. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of the 18F-FDG PET/CT were 42.9%, 59.7%, 29.3%, 78.2%, and 57.3%, respectively. On the CT scan, 18 of 21 recurrent gastric cancers were detected, and 7 cases were in agreement with the 18F-FDG PET/CT. The sensitivity and specificity of the CT scan were 85.8% and 87.3%, respectively, which are superior to the 18F-FDG PET/CT. When we diagnosed a recurrence based on either 18F-FDG PET/CT or CT scans, the sensitivity increased to 95.2% and the specificity decreased to 45.6%, when compared with the contrast CT scan alone.
Conclusion
18F-FDG PET/CT is an insufficient diagnostic method in detection of recurrence after curative gastrectomy, and even less accurate than contrast CT scan alone.
doi:10.3349/ymj.2011.52.1.81
PMCID: PMC3017712  PMID: 21155039
Gastric cancer; recurrence; 18F-FDG PET/CT scan; contrast CT scan

Results 1-25 (1362678)