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author:("kunia, tetsuo")
1.  Axillary Irradiation with High Tangent Fields for Clinically Node-Negative Breast Cancer: Can 3-D Conformal Radiotherapy with a Field-in-Field Technique Better Control the Axilla? 
Breast Care  2013;8(5):362-367.
Summary
Background
The target volume for postoperative breast irradiation is the remaining breast tissue, and the axillary region is not an intentional target volume.
Patients and Methods
Between 2001 and 2009, eligible women with pT1–2cN0/pN0(sn) breast cancer underwent breast-conserving therapy without axillary dissection. Treatment outcomes between 2 radiotherapy planning groups, high tangent fields with 2-dimensional (2-D) simulation-based planning and 3-dimensional (3-D) computed tomography-based planning with a field-in-field technique, were compared. The correlating factors for axillary failure were also calculated.
Results
In total, 678 patients were eligible. As of May 2009, the median follow-up times for the 2-D (n = 346) and 3-D (n = 332) groups were 94 and 52 months, respectively. Patient characteristics were balanced, except for a younger population in the 2-D group and more lymphovascular invasion in the 3-D group. On multivariate analysis, 2-D planning was the only risk factor for axillary failure. In the 2-D and 3-D groups, the 5-year cumulative incidences of axillary failure were 8 (3.1%) and 1 (0.3%) (log-rank p = 0.009), respectively. The respective 5-year overall survival rates were 97.4 and 98.4% (p = 0.4).
Conclusion
High tangent irradiation with 3-D planning improved axillary control compared to that with 2-D planning, suggesting that optimizing axillary dose distribution may impact outcomes.
doi:10.1159/000355708
PMCID: PMC3861852  PMID: 24415990
Breast cancer; Conformal radiotherapy; Sentinel lymph node biopsy
2.  Feasibility study of stereotactic body radiotherapy for peripheral lung tumors with a maximum dose of 100 Gy in five fractions and a heterogeneous dose distribution in the planning target volume 
Journal of Radiation Research  2014;55(5):988-995.
We evaluated toxicity and outcomes for patients with peripheral lung tumors treated with stereotactic body radiation therapy (SBRT) in a dose-escalation and dose-convergence study. A total of 15 patients were enrolled. SBRT was performed with 60 Gy in 5 fractions (fr.) prescribed to the 60% isodose line of maximum dose, which was 100 Gy in 5 fr., covering the planning target volume (PTV) surface (60 Gy/5 fr. − (60%-isodose)) using dynamic conformal multiple arc therapy (DCMAT). The primary endpoint was radiation pneumonitis (RP) ≥ Grade 2 within 6 months. Toxicities were graded according to the Common Terminology Criteria for Adverse Events, version 4.0. Using dose–volumetric analysis, the trial regimen of 60 Gy/5 fr. − (60%-isodose) was compared with our institutional conventional regimen of 50 Gy/5 fr. − (80%-isodose). The enrolled consecutive patients had either a solitary peripheral tumor or two ipsilateral tumors. The median follow-up duration was 22.0 (12.0–27.0) months. After 6 months post-SBRT, the respective number of RP Grade 0, 1 and 2 cases was 5, 9 and 1. In the Grade 2 RP patient, the image showed an organizing pneumonia pattern at 6.0 months post-SBRT. No other toxicity was found. At last follow-up, there was no evidence of recurrence of the treated tumors. The target volumes of 60 Gy/ 5 fr. − (60%-isodose) were irradiated with a significantly higher dose than those of 50 Gy/5 fr. − (80%-isodose), while the former dosimetric parameters of normal lung were almost equivalent to the latter. SBRT with 60 Gy/5 fr. − (60%-isodose) using DCMAT allowed the delivery of very high and convergent doses to peripheral lung tumors with feasibility in the acute and subacute phases. Further follow-up is required to assess for late toxicity.
doi:10.1093/jrr/rru037
PMCID: PMC4202295  PMID: 24833770
stereotactic body ridiotherapy; lung cancer; dose-escalation study; prescription dose; Phase I study; homogeneity index
3.  Role of stereotactic body radiotherapy for oligometastasis from colorectal cancer 
Systemic chemotherapy has enabled prolongation of survival in patients with stage IV colorectal cancer. This has subsequently increased the relative significance of local therapy for patients with oligometastases because they can be cured by removal of oligometastatic lesions. One of the most frequently reported tumor histologies for oligometastases is colorectal cancer. Resection is the standard therapy in most settings of oligometastases. Recently, studies have shown that stereotactic body radiotherapy (SBRT) may become a treatment option that provides high local control with minimal morbidity. Two-year local control rates following SBRT for hepatic and pulmonary oligometastases are almost over 80% and are even higher for patients treated with high-dose regimens. The indications of SBRT for other metastatic sites or conditions include isolated lymph nodes, spinal and adrenal metastasis, and post-surgical pelvic recurrence. Many retrospective studies have indicated that SBRT for various lesions results in good outcomes with low morbidity, both in the curative and palliative setting. However, few reports with a high level of evidence have indicated the efficacy of SBRT compared to standard therapy. Hereafter, the optimal indication of SBRT needs to be prospectively investigated to obtain convincing evidence.
doi:10.3748/wjg.v20.i15.4220
PMCID: PMC3989958  PMID: 24764660
Oligometastasis; Colorectal cancer; Radiation therapy; Stereotactic ablation body radiation therapy; Local therapy
4.  Role of stereotactic body radiation therapy for hepatocellular carcinoma 
The integration of new technologies has raised an interest in liver tumor radiotherapy, with literature evolving to support its efficacy. These advances, particularly stereotactic body radiation therapy (SBRT), have been critical in improving local control or potential cure in liver lesions not amenable to first-line surgical resection or radiofrequency ablation. Active investigation of SBRT, particularly for hepatocellular carcinoma (HCC), has recently started, yielding promising local control rates. In addition, data suggest a possibility that SBRT can be an alternative option for HCC unfit for other local therapies. However, information on optimal treatment indications, doses, and methods remains limited. In HCC, significant differences in patient characteristics and treatment availability exist by country. In addition, the prognosis of HCC is greatly influenced by underlying liver dysfunction and treatment itself in addition to tumor stage. Since they are closely linked to treatment approach, it is important to understand these differences in interpreting outcomes from various reports. Further studies are required to validate and maximize the efficacy of SBRT by a large, multi-institutional setting.
doi:10.3748/wjg.v20.i12.3100
PMCID: PMC3964382  PMID: 24696597
Hepatocellular carcinoma; Liver cirrhosis; Liver neoplasms; Radiation therapy; Stereotactic body radiation therapy
5.  Clinical characteristics of brain metastases from lung cancer according to histological type: Pretreatment evaluation and survival following whole-brain radiotherapy 
Molecular and Clinical Oncology  2013;1(4):692-698.
The histological type of lung cancer in patients with brain metastases may affect response to treatment and survival. We evaluated the clinical characteristics of brain metastases from lung cancer according to histological type in 70 consecutive patients with brain metastases from histologically confirmed lung cancer, who had been previously treated with whole-brain radiotherapy (WBRT). Histological type was divided into three categories: adenocarcinoma, small-cell lung carcinoma (SCLC) and other non-small cell lung cancer (NSCLC). The number, size and maximum diameter of brain metastases, the size and maximum diameter of peritumoral edema, the ratio of tumor and peritumoral edema, the asymptomatic ratio, the tumor size reduction rate, the complete response (CR) rate, the intracranial progression-free survival (PFS) and the overall survival (OS) were also evaluated. The median survival time for all patients was 26.2 weeks. Patients with SCLC exhibited a significantly smaller edema size and maximum diameter of edema compared to patients with other NSCLC (P=0.016 and 0.010, respectively). The ratio of tumor and peritumoral edema was also significantly lower in patients with SCLC compared to that in patients with adenocarcinoma and other NSCLC (P= 0.001). Significant differences in intracranial PFS and OS between adenocarcinoma and other NSCLC were also observed (P=0.018 and 0.004, respectively). Patients with adenocarcinoma who were treated with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) following WBRT, demonstrated a significant improvement in intracranial PFS and OS (P=0.008 and 0.004, respectively). The findings presented in this study may provide useful information for the management of brain metastases. Patients with SCLC exhibit a tendency to develop peritumoral edema to a lesser extent, compared to patients with other histological tumor types. Findings in the present study suggest that patients with adenocarcinoma, particularly those treated with EGFR-TKIs, exhibit improved survival rates.
doi:10.3892/mco.2013.130
PMCID: PMC3915483  PMID: 24649230
tyrosine kinase inhibitors; peritumoral edema
6.  Evaluation of beam hardening and photon scatter by brass compensator for IMRT 
Journal of Radiation Research  2012;53(6):999-1005.
When a brass compensator is set in a treatment beam, beam hardening may take place. This variation of the energy spectrum may affect the accuracy of dose calculation by a treatment planning system and the results of dose measurement of brass compensator intensity modulated radiation therapy (IMRT). In addition, when X-rays pass the compensator, scattered photons are generated within the compensator. Scattered photons may affect the monitor unit (MU) calculation. In this study, to evaluate the variation of dose distribution by the compensator, dose distribution was measured and energy spectrum was simulated using the Monte Carlo method. To investigate the influence of beam hardening for dose measurement using an ionization chamber, the beam quality correction factor was determined. Moreover, to clarify the effect of scattered photons generated within the compensator for the MU calculation, the head scatter factor was measured and energy spectrum analyses were performed. As a result, when X-rays passed the brass compensator, beam hardening occurred and dose distribution was varied. The variation of dose distribution and energy spectrum was larger with decreasing field size. This means that energy spectrum should be reproduced correctly to obtain high accuracy of dose calculation for the compensator IMRT. On the other hand, the influence of beam hardening on kQ was insignificant. Furthermore, scattered photons were generated within the compensator, and scattered photons affect the head scatter factor. These results show that scattered photons must be taken into account for MU calculation for brass compensator IMRT.
doi:10.1093/jrr/rrs048
PMCID: PMC3483849  PMID: 22915779
Brass compensator IMRT; beam hardening; dose distribution; quality correction factor; scatter photon
7.  Incidence of seed migration to the chest, abdomen, and pelvis after transperineal interstitial prostate brachytherapy with loose 125I seeds 
Background
The aim was to determine the incidence of seed migration not only to the chest, but also to the abdomen and pelvis after transperineal interstitial prostate brachytherapy with loose 125I seeds.
Methods
We reviewed the records of 267 patients who underwent prostate brachytherapy with loose 125I seeds. After seed implantation, orthogonal chest radiographs, an abdominal radiograph, and a pelvic radiograph were undertaken routinely to document the occurrence and sites of seed migration. The incidence of seed migration to the chest, abdomen, and pelvis was calculated. All patients who had seed migration to the abdomen and pelvis subsequently underwent a computed tomography scan to identify the exact location of the migrated seeds. Postimplant dosimetric analysis was undertaken, and dosimetric results were compared between patients with and without seed migration.
Results
A total of 19,236 seeds were implanted in 267 patients. Overall, 91 of 19,236 (0.47%) seeds migrated in 66 of 267 (24.7%) patients. Sixty-nine (0.36%) seeds migrated to the chest in 54 (20.2%) patients. Seven (0.036%) seeds migrated to the abdomen in six (2.2%) patients. Fifteen (0.078%) seeds migrated to the pelvis in 15 (5.6%) patients. Seed migration occurred predominantly within two weeks after seed implantation. None of the 66 patients had symptoms related to the migrated seeds. Postimplant prostate D90 was not significantly different between patients with and without seed migration.
Conclusion
We showed the incidence of seed migration to the chest, abdomen and pelvis. Seed migration did not have a significant effect on postimplant prostate D90.
doi:10.1186/1748-717X-6-130
PMCID: PMC3206434  PMID: 21974959
Brachytherapy; 125I; Migration; Prostate cancer; Seed
8.  Definitive chemoradiotherapy of limited-disease small cell lung cancer: Retrospective analysis of new predictive factors affecting treatment results 
Oncology Letters  2011;2(5):855-860.
The aim of this study was to evaluate potential predictive factors in the treatment of limited-disease small cell lung cancer (LD-SCLC). A total of 33 patients with LD-SCLC who underwent definitive chemoradiotherapy at our institute between April 1996 and May 2007 were enrolled in our retrospective study. The relationship between a range of potential predictive factors and the initial response, time to progression and pattern of failure was analyzed. The factors evaluated included the tumor markers Pro-gastrin-releasing peptide (Pro-GRP) and neuron-specific enolase; net tumor size (sum of each lesion mass on computed tomography at 1-cm intervals); total radiation dose; biological effective dose (BED); overall treatment time (OTT); time between the start of any type of treatment and the end of radiation therapy (SER). In addition, the novel factors of radiation dose-intensity (RDI = BED/OTT) and RDI/NTS (= RDI/net tumor size) were defined. Of the 33 patients evaluated in our study, 22 (67%) achieved a complete response (CR) and 27 (82%) experienced treatment failure or recurrence. High RDI/NTS values showed a significant correlation with CR (P=0.043). Prolonged OTT and lower values of RDI and RDI/NTS showed a significant correlation with recurrence within 12 months (P=0.022, 0.033 and 0.015, respectively). The lower values of RDI and RDI/NTS showed a significant correlation with distant metastasis as a first failure site (P=0.038 and 0.044, respectively). Patients with RDI/NTS ≥0.08 had a more favorable prognosis (P=0.045). Thus, RDI and RDI/NTS may become beneficial predictive factors in the treatment of LD-SCLC. However, further studies are required to confirm our preliminary results.
doi:10.3892/ol.2011.361
PMCID: PMC3408015  PMID: 22866140
9.  Preimplant factors affecting postimplant CT-determined prostate volume and the CT/TRUS volume ratio after transperineal interstitial prostate brachytherapy with 125I free seeds 
Background
The aim was to identify preimplant factors affecting postimplant prostate volume and the increase in prostate volume after transperineal interstitial prostate brachytherapy with 125I free seeds.
Methods
We reviewed the records of 180 patients who underwent prostate brachytherapy with 125I free seeds for clinical T1/T2 prostate cancer. Eighty-one (45%) of the 180 patients underwent neoadjuvant hormonal therapy. No patient received supplemental external beam radiotherapy. Postimplant computed tomography was undertaken, and postimplant dosimetric analysis was performed. Univariate and multivariate analyses were performed to identify preimplant factors affecting postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.
Results
Preimplant prostate volume by transrectal ultrasound, serum prostate-specific antigen, number of needles, and number of seeds implanted were significantly correlated with postimplant prostate volume by computed tomography. The increase in prostate volume after implantation was significantly higher in patients with neoadjuvant hormonal therapy than in those without. Preimplant prostate volume by transrectal ultrasound, number of needles, and number of seeds implanted were significantly correlated with the increase in prostate volume after implantation. Stepwise multiple linear regression analysis showed that preimplant prostate volume by transrectal ultrasound and neoadjuvant hormonal therapy were significant independent factors affecting both postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.
Conclusions
The results of the present study show that preimplant prostate volume by transrectal ultrasound and neoadjuvant hormonal therapy are significant preimplant factors affecting both postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.
doi:10.1186/1748-717X-5-86
PMCID: PMC2954882  PMID: 20875137

Results 1-9 (9)