We evaluated the prognostic value of volume-based metabolic positron emission tomography (PET) parameters in patients with small cell lung cancer (SCLC) compared with other factors.
The subjects were 202 patients with pathologically proven SCLC who underwent pretreatment 18F-fluorodeoxyglucose (FDG) PET/computed tomography (CT). Volumetric metabolic parameters of intrathoracic malignant hypermetabolic lesions, including maximum and average standardized uptake value, sum of metabolic tumor volume (MTV), and sum of total lesion glycolysis (TLG) were measured.
164 patients had died during follow-up (median 17.4 months) and median overall survival was 14 months. On univariate survival analysis, age, stage, treatment modality, sum of MTV (cutoff = 100 cm3), and sum of TLG (cutoff = 555) were significant predictors of survival. There was a very high correlation between the sum of MTV and the sum of TLG (r = 0.963, P < 0.001). On multivariate survival analysis, age (HR = 1.04, P < 0.001), stage (HR = 2.442, P < 0.001), and sum of MTV (HR = 1.662, P = 0.002) were independent prognostic factors. On subgroup analysis based on limited disease (LD) and extensive disease (ED), sum of MTV and sum of TLG were significant prognostic factors only in LD.
Both sum of MTV and sum of TLG of intrathoracic malignant hypermetabolic lesions are important independent prognostic factors for survival in patients with SCLC, in addition to age and clinical stage. However, it may be more useful in limited disease rather than in extensive disease.
Small cell lung cancer; [18F]FDG-PET/CT; Metabolic tumor volume; Total lesion glycolysis; Prognosis
We investigated the prognostic values of volume-based metabolic parameters by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) in gallbladder carcinoma patients and compared them with other prognostic parameters.
Materials and Methods
We enrolled 44 patients, who were initially diagnosed with gallbladder carcinoma and undergoing 18F-FDG PET/CT. Various metabolic volume-based PET parameters of primary tumors, including maximum and average standardized uptake values (SUVmax, SUVavg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), were measured in gallbladder carcinoma patients using mediastinal blood pool activity as a threshold SUV for determining the tumor boundaries. Overall survival analysis was performed using the Kaplan-Meier method with PET parameters and other clinical variables. For determining independent prognostic factors, Cox proportional hazards regression analysis was performed.
Of the 44 enrolled patients, cancer- or treatment-related death occurred in 30 (68.2 %). The mean clinical follow-up period was 22.2 ± 10.4 m (range, 0.6-35.9 m). Univariate analysis demonstrated that clinical or pathologic TNM stage (P < 0.001), treatment modality (P < 0.001), MTV (cutoff = 135 cm3, P = 0.001), and TLG (cutoff = 7,090, P < 0.05) were significant prognostic factors. In multivariate analysis, both clinical or pathologic TNM stage [hazard ratio (HR) = 2.019 (I vs II), 21.287 (I vs III), and 24.354 (I vs IV); P = 0.001) and TLG (HR = 2.930; P < 0.05) were independent prognostic factors for predicting overall survival.
In gallbladder cancer, TLG of the primary tumor, a volume-based metabolic parameter, is a significant independent prognostic factor for overall survival in conjunction with the clinical or pathological TNM stage.
Gallbladder carcinoma; Prognosis; 18F-FDG; PET/CT; Metabolic tumor volume; Total lesion glycolysis
We investigated PET/CT diagnostic criteria for differentiating benign from malignant parotid lesions with focal 18F-FDG uptake.
The subjects of the study were 272 patients who exhibited focal 18F-FDG uptake of the parotid gland. Sixty-eight pathologically confirmed parotid lesions from 67 patients were included. The maximum SUV (SUVmax), uptake patterns (homogeneous vs. heterogeneous), size measured by CT, maximum Hounsfield units (HUmax) and margins on CT (well vs. ill defined) of each parotid lesion on PET/CT images were compared with final diagnoses.
Thirty-two parotid lesions were histologically proven to be malignant. There were significant differences in uptake patterns (cancer incidence, heterogeneous:homogeneous = 79.2%:29.5%, p < 0.0001) and margins on CT (cancer incidence, ill:well defined = 84.4%:13.3%, p < 0.0001) between benign and malignant lesions. The cancer risks of parotid lesions were 89.5% with heterogeneous uptake and ill-defined margins, 70.6% with heterogeneous uptake or ill-defined margins (no overlap in subjects) and 9.3% with homogeneous uptake and well-defined margins (p < 0.0001). When any lesion with heterogeneous uptake or ill-defined margins was regarded as malignant, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 90.6% (29/32), 80.6% (29/36), 80.6% (29/36), 90.6% (29/32) and 85.6% (58/68), respectively. For predicting malignancy, combined PET/CT criteria showed better sensitivity, NPV and accuracy than PET-only criteria, and had a tendency to have more accurate results than CT-only criteria. There were no significant differences in SUVmax, size or HUmax between benign and malignant lesions.
Uptake patterns and margins on CT are useful PET/CT diagnostic criteria for differentiating benign from malignant lesions.
Electronic supplementary material
The online version of this article (doi:10.1007/s13139-012-0135-y) contains supplementary material, which is available to authorized users.
F-FDG; PET; PET/CT; Parotid gland; Cancer
We investigated the clinical significance of incidental diffuse thyroid uptake (DTU) on 18F-FDG PET in subjects without a history of cancer.
Materials and Methods
This study included 2062 studies from adults who underwent 18F-FDG PET as a cancer screening program. Subjects were divided into the following two groups: with (group I) or without (group II) DTU. The presence of DTU and the thyroid visual grading score were compared with thyroid function tests, serum anti-microsomal antibody (AMA) levels, and the presence of diffuse parenchymal change (DPC) on ultrasonography (USG).
DTU was found in 6.6% of the scans (137/2062). Serum thyroid stimulating hormone (TSH) and AMA levels were significantly higher in group I than in group II. Increased AMA level (55.1%) and DPC (48.7%) were more frequently found in group I (p < 0.001). The proportion of subjects with any abnormal results in serum free thyroxine, triiodothyronine, TSH, or AMA levels or DPC on USG was significantly higher in group I than in group II (71.5% vs. 10.6%, p < 0.001), and was significantly and gradually increased according to the visual grading score group (0 vs. 1-2 vs. 3-4 = 10.6% vs. 58.5% vs. 90.9%, p < 0.001). TSH and is AMA levels were significantly increased according to the visual grading score.
The presence or degree of incidental DTU on 18F-FDG PET is closely correlated with increased serum AMA and TSH levels, and the presence of DPC on USG. Therefore, the most plausible pathological cause of DTU may be cell damage by an autoimmune mechanism.
Positron emission tomography; 18F-Fluorodeoxyglucose; Diffuse thyroid uptake; Autoimmune thyroid disease
This study aimed to investigate the differential findings in clinical and biochemical features, and Tc-99m sestamibi (MIBI) dual-phase parathyroid scintigraphy for malignant and benign parathyroid lesions in patients with primary hyperparathyroidism.
Subjects were 102 parathyroid lesions from 91 patients with primary hyperparathyroidism. Scintigraphic findings included radioactivity grade, uptake pattern, uptake contour, lesion size on early and delayed images, and degree of washout. Clinical and biochemical features were also evaluated. Histopathology confirmed the final diagnosis for all the patients.
Final diagnoses were 94 benign parathyroid lesions and 8 parathyroid carcinomas. The patients with parathyroid carcinoma were significantly older (p = 0.002) and had significantly higher serum parathyroid hormone concentrations than those with benign parathyroid lesions (p < 0.001). All malignant parathyroid lesions showed intense radioactivity similar to or greater than the submandibular gland activity on delayed images (p = 0.007), and little radioactivity difference between early and delayed images (p = 0.012). The cancer incidence for parathyroid lesions with both intense radioactivity and no washout was 17.0% (8/47). When parathyroid lesions with all of the above-mentioned findings were regarded as malignant, the cancer incidence significantly increased from 17.0% to 33.3% (8/24, p < 0.001).
For Tc-99m MIBI dual-phase parathyroid scintigraphy, uptake grade on delayed images and washout were significantly useful diagnostic criteria for differentiating benign from malignant parathyroid lesions, along with age and parathyroid hormone serum concentration.
Primary hyperparathyroidism; Parathyroid carcinoma; Parathyroid adenoma; Parathyroid hyperplasia; Tc-99m Sestamibi; Parathyroid scintigraphy
To evaluate the prognostic value of volume-based metabolic parameters measured with 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) in patients with clinically node-negative (cN0) oral tongue squamous cell carcinoma (OTSCC) as compared with other prognostic factors.
Materials and Methods
In this study, we included a total of 57 patients who had been diagnosed with cN0 tongue cancer by radiologic, 18F-FDG PET/CT, and physical examinations. The maximum standardized uptake value (SUVmax), average SUV (SUVavg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for primary tumors were measured with 18F-FDG PET. The prognostic significances of these parameters and other clinical variables were assessed by Cox proportional hazards regression analysis.
In the univariate analysis, pathological node (pN) stage, American Joint Committee on Cancer (AJCC) stage, SUVmax, SUVavg, MTV, and TLG were significant predictors for survival. On a multivariate analysis, pN stage (hazard ratio = 10.555, p = 0.049), AJCC stage (hazard ratio = 13.220, p = 0.045), and MTV (hazard ratio = 2.698, p = 0.033) were significant prognostic factors in cN0 OTSCC patients. The patients with MTV ≥ 7.78 cm3 showed a worse prognosis than those with MTV < 7.78 cm3 (p = 0.037).
The MTV of primary tumor as a volumetric parameter of 18F-FDG PET, in addition to pN stage and AJCC stage, is an independent prognostic factor for survival in cN0 OTSCC.
18F-FDG PET/CT; Oral tongue squamous cell carcinoma; SUV; Metabolic tumor volume; Total lesion glycolysis; Prognosis prediction
The extent and intensity of 18F-FDG uptake in prostate cancer patients are known to be variable, and the clinical significance of focal 18F-fluorodeoxyglucose (18F-FDG) uptake that is incidentally found on positron emission tomography (PET) has not been established. We investigated the clinical significance of incidental focal prostate uptake of 18F-FDG on PET/computed tomography (CT) and analyzed differential findings on PET/CT between malignant and benign uptake.
A total of 14,854 whole-body 18F-FDG PET/CT scans (4,806 that were conducted during cancer screening and 10,048 that were conducted to evaluate suspected or alleged cancer outside of the prostate) were retrospectively reviewed to determine the presence, location, multiplicity and maximum standardized uptake value (SUVmax) of focal prostate uptake and combined calcification. The final diagnosis determined by serum prostate-specific antigen (PSA) level and biopsy was compared with PET findings.
Incidental focal prostate uptake was observed in 148 of 14,854 scans (1.0 %). Sixty-seven of these 148 subjects who had diagnostic confirmation were selected for further analysis. Prostate cancer was diagnosed in nine of 67 subjects (13.4%). The remaining 58 subjects had no malignancy in the prostate based on normal serum PSA level (n = 53), or elevated serum PSA level with a negative biopsy result (n = 5). While 84.6% (11/13) of malignant uptake was peripherally located in the prostate glands, 60.2% (50/83) of benign uptake was centrally located (p < 0.05). The positive predictive value of peripheral focal uptake for malignancy was 25%. The SUVmax, multiplicity and combined calcification were not significantly different between the two groups.
Although incidental focal 18F-FDG uptake in the prostate is not common, the incidence of cancer with focal uptake is not low. Therefore, these findings deserve further evaluation. The location of the focal prostate uptake may help with the selection of high-risk prostate cancer patients.
18F-fluorodeoxyglucose; PET/CT; Prostate gland; Prostate cancer
Clinically detectable well-differentiated metastatic thyroid carcinoma to the kidney is rare and should be differentiated from primary renal malignancy. We report a case of renal metastases from follicular thyroid carcinoma (FTC) diagnosed by I-131 whole body scan. Additional features of this case different from previous case reports are solitary renal metastasis on I-131 whole body scan and mimicry of renal cell carcinoma on contrast-enhanced computed tomography.
Follicular thyroid carcinoma; Renal metastasis; Renal cell carcinoma; I-131 whole body scan
We report here on a rare case of primary AL hepatic amyloidosis associated with multiple myeloma in a 64-year-old woman. The patient was referred for evaluating her progressive jaundice and right upper quadrant pain. 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) showed diffusely and markedly increased 18F-FDG uptake in the liver. Although there have been several case studies showing positive 18F-FDG uptake in pulmonary amyloidosis, to the best of our knowledge, the 18F-FDG PET/CT findings of hepatic amyloidosis or primary hepatic amyloidosis associated with multiple myeloma have not been reported previously.
Amyloidosis; Multiple Myeloma; Liver; 18F-FDG PET
This study was conducted to compare 18F-FDG PET/CT and electromyography (EMG) mapping in patients with primary cervical dystonia (PCD) to find dystonic superficial cervical muscles.
Ten consecutive patients with PCD (M:F = 5:5, age 44 ± 13 years) whose dystonic posture was not relieved with conventional muscle relaxant therapy were included. Target cervical muscles for the comparison between 18F-FDG PET/CT and EMG mapping were four representative superficial bilateral cervical muscles: splenius capitis muscle, sternocleidomstoid muscle, upper trapezius muscle, and leavator scapulae muscle. The diagnostic efficacy was compared between 18F-FDG PET/CT and EMG mapping using physical exam and measurement of rotation angle as the gold standard.
Among 80 muscles evaluated, there were 21 (26%) dystonic superficial cervical muscles assessed with physical exam and motion analysis. The sensitivity, specificity, and accuracy for localizing dystonic muscles were 76, 92, and 88% for 18F-FDG PET/CT, and 95, 66, and 74% for EMG mapping, respectively. The sensitivity of EMG mapping was significantly higher than that of 18F-FDG PET/CT. In contrast, 18F-FDG PET/CT was significantly superior to EMG mapping for specificity and accuracy.
18F-FDG PET/CT is more specific and accurate than EMG mapping for finding superficial dystonic cervical muscles. The high sensitivity of EMG mapping suggests that 18F-FDG PET/CT and EMG mapping are complementary for finding dystonic superficial cervical muscles.
Primary cervical dystonia; Spasmodic torticollis; 18F-FDG; PET/CT; Electromyography
We aimed to evaluate prospectively the efficacy of positron emission tomography (PET)/computed tomography (CT) plus brain magnetic resonance imaging (MRI) for detecting extrathoracic metastases in lung adenocarcinoma. Metastatic evaluations were feasible for 442 consecutive patients (M:F=238:204; mean age, 54 yr) with a lung adenocarcinoma who underwent PET/CT (CT, without IV contrast medium injection) plus contrast-enhanced brain MRI. The presence of metastases in the brain was evaluated by assessing brain MRI or PET/CT, and in other organs by PET/CT. Diagnostic efficacies for metastasis detection with PET/CT plus brain MRI and with PET/CT only were calculated on a per-patient basis and compared from each other. Of 442 patients, 88 (20%, including 50 [11.3%] with brain metastasis) had metastasis. Regarding sensitivity of overall extrathoracic metastasis detection, a significant difference was found between PET/CT and PET/CT plus brain MRI (68% vs. 84%; P=0.03). As for brain metastasis detection sensitivity, brain MRI was significantly higher than PET/CT (88% vs. 24%; P<0.001). By adding MRI to PET/CT, brain metastases were detected in additional 32 (7% of 442 patients) patients. In lung adenocarcinoma patients, significant increase in sensitivity can be achieved for detecting extrathoracic metastases by adding dedicated brain MRI to PET/CT and thus enhancing brain metastasis detection.
PET/CT Scan; Lung Neoplasms; Neoplasm Metastasis; Brain; Magnetic Resonance Imaging; Neoplasm Staging
We aimed to compare the prognoses of patients with pathologically true negative (P-TN) N2 and PET/CT false negative (FN) results in stage T1 non-small cell lung cancer (NSCLC).
Materials and Methods
Our institutional review board approved this retrospective study with a waiver of informed consent. The study included 184 patients (124 men and 60 women; mean age, 59 years) with stage T1 NSCLC who underwent an integrated PET/CT and surgery. After estimating the efficacy of PET/CT for detecting N2 disease, we determined and compared disease-free survival (DFS) rates in three groups (P-TN [n = 161], PET/CT FN [n = 12], and PET/CT true positive [TP, n = 11]) using the Kaplan-Meier analysis and log-rank test.
Pathologic N2 disease was observed in 23 (12%) patients. PET/CT had an N2 disease detection sensitivity of 48% (11 of 23 patients), a specificity of 95% (153 of 161), and an accuracy of 89% (164 of 184). The 3-year DFS rate in the PET/CT FN group (31%, 95% confidence interval [CI]; 13.6-48.0%) was similar to that of the TP group (16%, 95% CI; 1.7-29.5%) (p = 0.649), but both groups had significantly shorter DFS rates than the P-TN group (77%, 95% CI; 72.0-81.2%) (p < 0.001).
The PET/CT shows a high specificity, but low sensitivity for detecting N2 disease in stage T1 NSCLC. Patients with PET/CT FN N2 disease have survival rates similar to PET/CT TP N2 disease patients, which are both substantially shorter than the survival rate of P-TN patients.
Lung neoplasms; Lung neoplasms, CT; Lung neoplasms, PET; Lung neoplasms, staging
The aim of this study was to assess the diagnostic efficacy of integrated PET/CT using fluorodeoxyglucose (FDG) for the differentiation of benign and metastatic adrenal gland lesions in patients with lung cancer and to compare the diagnostic efficacy with the use of PET alone.
Materials and Methods
Sixty-one adrenal lesions (size range, 5-104 mm; mean size, 16 mm) were evaluated retrospectively in 42 lung cancer patients. Both PET images alone and integrated PET/CT images were assessed, respectively, at two-month intervals. PET findings were interpreted as positive if the FDG uptake of adrenal lesions was greater than or equal to that of the liver, and the PET/CT findings were interpreted as positive if an adrenal lesion show attenuation > 10 HU and showed increased FDG uptake. Final diagnoses of adrenal gland lesions were made at clinical follow-up (n = 52) or by a biopsy (n = 9) when available. The diagnostic accuracies of PET and PET/CT for the characterization of adrenal lesions were compared using the McNemar test.
Thirty-five (57%) of the 61 adrenal lesions were metastatic and the remaining 26 lesions were benign. For the depiction of adrenal gland metastasis, the sensitivity, specificity, and accuracy of PET were 74%, 73%, and 74%, respectively, whereas those of integrated PET/CT were 80%, 89%, and 84%, respectively (p values; 0.5, 0.125, and 0.031, respectively).
The use of integrated PET/CT is more accurate than the use of PET alone for differentiating benign and metastatic adrenal gland lesions in lung cancer patients.
18F-FDG; PET; PET/CT; Lung cancer; Adrenal metastasis
We report the first case in Korea of a chronic expanding hematoma, which presented as a huge mass in the pleural cavity. A 67-year-old woman exhibiting a slowly-expanding intrathoracic mass, as revealed by a chest radiograph, was admitted to our hospital. The patient had undergone a pneumonectomy 37 years earlier during treatment for pulmonary tuberculosis. Computed tomography revealed a huge mass in her right hemithorax. The differential diagnosis of this mass included chronic empyema combined with a malignancy, such as lymphoma or a soft tissue sarcoma. The tumor, which was classified as an encapsulated chronic hematoma, was removed surgically. Samples sent for histopathological and microbiological analysis revealed no evidence of neoplasia or infection. The patient was finally diagnosed with a chronic expanding hematoma of the thorax. This case is particularly rare due to the patient's development of a very large mass after undergoing treatment for tuberculosis more than 30 years earlier.
Hematoma; thoracic neoplasms; tuberculosis; postoperative complications
Here, we describe a case of a solitary pulmonary nodule due to Mycobacterium intracellulare infection. To the best of our knowledge, this is the first case reported in Korea. A 45-year-old female, exhibiting no respiratory symptoms, was admitted to our hospital due to the appearance of a solitary pulmonary nodule on a chest radiograph. Computed tomography revealed a 2.5cm nodule with an irregular shape and some marginal spiculation in the right upper lobe. Positron emission tomography with fluorodeoxyglucose imaging revealed positive tumor uptake (maximum standardized uptake value=8.8). Bronchoscopy yielded no specific histological findings and no bacteriological findings. Percutaneous transthoracic lung biopsy revealed epithelioid granuloma but no acid-fast bacilli were detected. The patient received isoniazid, rifampin, ethambutol, and pyrazinamide for the treatment of "tuberculoma". Five weeks after the patient was admitted, numerous mycobacterial colonies were detected on a bronchial washing fluid culture. These colonies were subsequently identified as Mycobacterium intracellulare. A final diagnosis of M. intracellulare pulmonary disease was made, and the patient's treatment regimen was changed to a combination therapy consisting of clarithromycin, rifampin, and ethambutol.
Pulmonary coin lesion; atypical mycobacteria; Mycobacterium avium complex; tuberculosis; tuberculoma
The objective of this study was to evaluate the feasibility of sentinel lymph node biopsy by using a radiotracer lymphatic mapping technique in patients with squamous cell carcinoma of the oral cavity, and the diagnostic value of this technique. We studied twenty patients with previously untreated squamous cell carcinomas of the oral cavity and N0 necks. After the peritumoral injection of 99mTc filtered tin colloid preop-eratively, lymphoscintigraphy and intraoperative mapping using a gamma detector were performed to localize sentinel nodes. An open biopsy of the sentinel node was followed by complete neck dissection. We identified the sentinel nodes in 19 of 20 patients (95.0%) by lymphoscintigraphy and in all (100%) by intraoperative gamma detector. In all cases, the status of the sentinel node accurately predicted the pathologic status of the neck with the false negative rate being 0%. The negative predictive value for the absence of cervical metastases was 100%. In conclusion, our radio-localization technique of sentinel nodes using 99mTc filtered tin colloid in N0 squamous cell carcinomas of the oral cavity is technically feasible and appears to accurately predict the presence of the occult metastatic disease.
Sentinel Lymph Node Biopsy; Lymphatic Metastasis; Mouth Neoplasms; Radionuclide Imaging