Masahiro Sasaoka

Clinical assessment by MRI for patients with Stage II cervical carcinoma treated by radiation alone in multicenter analysis: are all patients with Stage II disease suitable candidates for chemoradiotherapy?

PURPOSE From recent randomized trials, patients with Stage II cervical carcinoma are thought to be candidates for chemoradiotherapy. To refine the strategy for Stage II patients, we performed a retrospective multi-institutional analysis using MRI. METHODS AND MATERIALS From three institutions, 84 patients with Stage II cancer diagnosed by MRI were entered into the study. All patients received intracavitary brachytherapy with (n = 83) or without (n = 1) external beam radiotherapy. Uni- and multivariate analyses were performed to identify the prognostic factors for overall survival (OAS), disease-free survival (DFS), pelvic control (PC), and distant metastasis-free survival (DMFS). RESULTS The 5-year DFS rate of patients with maximal tumor size (D(max)) > or =50 mm (46.2%) was significantly lower than that for patients with D(max) <50 mm (88.0%; p <0.0001). Large size or volume and lymph node swelling were also significant prognostic factors of OAS, DFS, PC, and DMFS. In the multivariate model, size or volume was a significant prognostic factor of OAS, DFS, PC, and DMFS, and lymph node swelling was a prognostic factor for DFS, PC, and DMFS. Using these two prognostic factors, patients were divided into 3 subgroups. The 5-year DFS rate of patients with risk 0 (D(max) <50 mm and negative lymph node swelling), 1 (D(max) > or =50 mm or positive lymph node swelling), and 2 (D(max) > or =50 mm and positive lymph nodes) was 93.2%, 53.3%, and 25.0%, respectively (p <0.0001). CONCLUSION In this stage-limiting analysis, we clarified the stratification according to clinical risk with the aid of MRI. For patients with low-risk factors, especially for elderly patients, radiation alone would probability be a feasible option. In the future, a randomized trial using criteria with MRI would help to identify the optimal strategy for patients with Stage II disease.

High dose rate endobronchial brachytherapy using a new applicator

BACKGROUND AND PURPOSE To obtain adequate spatial dose distribution for endobronchial brachytherapy, we applied reference dose points according to the bronchial diameter. For this purpose, we devised a new applicator of which the source transfer tube is contained in the center of the lumen for high dose rate (HDR) brachytherapy. MATERIALS AND METHODS Thirty-nine patients with endobronchial cancer underwent endobronchial brachytherapy using an HDR afterloading machine with an Ir-192 source. In the nine patients treated with curative intent, treatment consisted of external beam radiotherapy with 40-60 Gy for 4-6 weeks and endobronchial brachytherapy with three fractions of 6 Gy. The 30 patients treated with palliative intent received one fraction of 10 Gy with or without external beam irradiation. The reference dose points were prescribed according to bronchial diameter, which was measured by the applicators radiopaque wing expansion reflecting the bronchial caliber. RESULTS The new applicator could be placed at the intended site in 37 lesions. Of 12 lesions which were treated with curative intent, eight (67%) disappeared after brachytherapy. The overall survival at 3 years of all patients and of the patients treated with curative intent was 22 and 64%, respectively. CONCLUSIONS The source should be positioned in the center of the lumen; this technique is helpful in reducing side-effects caused by inhomogeneous dose distribution of endobronchial brachytherapy.

Multi-Institutional Analysis of Early Glottic Cancer from 2000 to 2005

BackgroundThe purpose of this study is to analyze the outcome of patients with early glottic cancer (GC) treated with radiotherapy (RT) with or without chemotherapy at 10 institutions in the Tokai District, Japan.MethodsTen institutions combined data from 279 patients with T1-T2 GC treated with RT with or without chemotherapy between 2000 and 2005. The overall survival rate, disease-specific survival rate, and local control rate were evaluated in 270 patients, except for incomplete cases due to issues such as discontinuation, using the method of Kaplan-Meier and compared using the log-rank test. Results were considered statistically significant at the level of p < 0.05.ResultsFor 122 patients, the tumors were classified as T1a, while 64 patients had T1b tumors, and 84 patients had T2 tumors. In three cases of T1 tumors, the subtype was unknown. Combined chemoradiotherapy (CRT) was administered during each stage, and various chemotherapy drugs and regimens were used. The median follow-up period was 55.4 months. The 5-year LC rates for T1a, Tb, and T2 tumors in all patients were 87.9%, 82.7%, and 74.1%, respectively. The difference between T1a and T2 was statistically significant (p = 0.016). The 5-year LC rates for T1a, Tb, and T2 with CRT were 92.7%, 78.6%, and 80.7%, respectively, while the rates with radiation alone were 86.5%, 83.8%, and 64.4%, respectively. The difference between CRT and RT alone was not statistically significant in each stage.ConclusionsIn this survey, CRT was performed for early GC at most institutions in clinical practice. Our data showed no statistical difference in the LC rates between CRT and RT alone in each stage. However, there was a tendency for the LCRs of the CRT group to be more favorable than those of the RT group in the T2-stage.

Aichi Cancer Center 10-year experience with conservative breast treatment of early breast cancer: retrospective analysis regarding failure patterns and factors influencing local control

PURPOSE We analyzed the clinical results of conservative breast therapy in our institute to determine the risk factors influencing local and distant disease recurrence. METHODS AND MATERIALS From 1989 to 1997, 301 breasts of 295 women with early breast cancer were treated with conservative surgery and adjuvant radiotherapy. There were 212 incidences of Stage I breast cancer, and 89 of Stage II. Patients were routinely treated with local resection, axillar dissection, and 46--50 Gy irradiation given in 23--25 fractions. Some also received a radiation boost to the tumor bed. RESULTS The 5-/8-year overall survival, disease-free survival, and local control rates were 93.2/91.5%, 86.0/80.6%, and 95.1/92.5%, respectively. Using both univariate and multivariate analyses, tumor volume, estrogen receptor status, and age < 40 years were significant prognostic factors for disease-free survival. Both age < 40 years and surgical method had a strong effect on local control by uni- and multivariate analysis. Surgical margin status was a significant prognostic factor for local control at the univariate level (p < 0.0001), though it had only borderline significance at the multivariate level (p = 0.08). No patient experienced severe morbidity due to radiotherapy. CONCLUSION The results obtained are comparable to previously reported data. Although the follow-up period was too short to draw definite conclusions about long-term outcomes, the outcome from conservative breast treatment was acceptable.

Rectal dose reduction using three-dimensional conformal radiotherapy for locally advanced prostate cancer: A combination of conformal dynamic-arc and five-static field technique

BACKGROUND AND PURPOSE The aims of this study are to compare our three-dimensional conformal radiotherapy (3D-CRT) plan using a combination of conformal dynamic-arc and five-static field (DASF) technique with other 3D-CRT plans for prostate cancer, and to estimate whether dose escalation is possible with DASF radiotherapy (DASF-RT). METHODS AND MATERIALS Twenty patients with prostate cancer were included in this study. For each patient, five different treatment plans including DASF-RT were created to entire prostate and seminal vesicles. Dose distribution and rectal dose-volume histogram (DVH) for each planning technique were compared. RESULTS In DASF-RT treatment plan, rectum V40, V50, V60, and V70 were 61.6%, 39.6%, 21.4%, and 0.6%, respectively. Compared with four 3D-CRT techniques, DASF-RT technique significantly reduce rectum V50 to V70 without increasing irradiated bladder and femoral head volumes. In addition, in the simulation of dose escalation to 76Gy, the increase of each rectal dose-volume parameter (V40 to V75) was small enough. However, in dose escalation to 78Gy, rectum V75 exceeded 5%. CONCLUSION DASF-RT technique could significantly reduce rectal volumes receiving 50-70Gy compared with other 3D-CRT techniques. DASF-RT was safe and feasible for dose escalation to 76Gy in prostate radiotherapy.

Long-term clinical outcomes of postoperative pelvic radiotherapy with or without prophylactic paraaortic irradiation for stage I-II cervical carcinoma with positive lymph nodes: retrospective analysis of predictive variables regarding survival and failure patterns.

We performed retrospective analysis to classify the risk hazard of patients with stage I-II cervical cancer with lymph node metastases treated with postoperative radiotherapy. From 1981 to 1995, 106 patients with early stage cervical carcinoma who received adjuvant pelvic radiation were entered in the analysis. The median patient age was 53.0 years (range 21–73). The median dose of 45.3 Gy (range, 32.1–56.4 Gy) was delivered over the whole pelvis. Seventy patients also received prophylactic paraaortic radiation (median 44 Gy; range 22–46 Gy). The 5/10-year overall survival (OAS), disease-free survival (DFS), pelvic control, and distant metastasis-free survival rates were 69.1/63.5%, 62.4/58.1%, 85.7/84.3%, and 74.1/71.6%, respectively. In the uni-/multivariate analyses, the significant prognostic factors of OAS and DFS proved to be disease stage, duration period between operation and radiotherapy, histology, and presence or absence of common iliac lymph node metastasis. Using the results of these analyses, we devised a predictive model for DFS. In this model, the 5-year DFS rates of patients with low (N = 35), intermediate (N = 59), and high-risk factors (N = 12) were 88.1%, 56.7%, and 16.7%, respectively (p < 0.0001). The majority of analyzed patients did not have adequate DFS estimates in this series. High-risk patients should receive a more intensive strategy, such as concurrent chemoradiotherapy. On the other hand, the effort to reduce toxicity should be considered carefully.