L. Paoletti

Concurrent Cyclophosphamide, Methotrexate, and 5-Fluorouracil Chemotherapy and Radiotherapy for Early Breast Carcinoma

PURPOSE The optimal sequencing of adjuvant chemotherapy (CT) and radiation therapy (RT) in patients with early-stage breast cancer remains unclear. PATIENTS AND METHODS We retrospectively compared 485 patients treated with conservative breast surgery and postoperative whole-breast RT and six courses of CMF (cyclophosphamide 600 mg/m(2), methotrexate 40 mg/m(2), and 5-fluorouracil 600 mg/m(2)) with 300 patients who received postoperative CMF only and with 509 patients treated with postoperative whole-breast RT only. The mean radiation dose delivered was 50 Gy (range, 46-52 Gy) with standard fractionation. The boost dose was 6-16 Gy according to resection margins and at the discretion of the radiation oncologist. Acute and late RT toxicity were scored using respectively the Radiation Therapy Oncology Group and the Late Effects in Normal Tissues Subjective, Objective, Management and Analytic scale. RESULTS A slightly higher Grade 2 acute skin toxicity was recorded in the concurrent group (21.2% vs. 11.2% of the RT only group, p < 0.0001). RT was interrupted more frequently in the CMF/RT group respective to the RT group (8.5% vs. 4.1%; p = 0.006). There was no difference in late toxicity between the two groups. All patients in the concurrent group successfully received the planned dose of RT and CT. Local recurrence rate was 7.6% in CT/RT group and 9.8% in RT group; this difference was not statistically significant at univariate analysis (log-rank test p = 0.98). However, at multivariate analysis adjusted also for pathological tumor, pathological nodes, and age, the CT/RT group showed a statistically lower rate of local recurrence (p = 0.04). CONCLUSIONS Whole-breast RT and concurrent CMF are a safe adjuvant treatment in terms of toxicity.

EP-1156: Radiotherapy for ductal carcinoma in situ: patterns of recurrence and risk factors stratification

withdrawn EP-1158 Should breathing adapted radiation therapy also be applied for right-sided breast irradiation? M. Essers Dr. Bernard Verbeeten Instituut, Department of Medical Physics, Tilburg, The Netherlands , P.M. Poortmans, K. Verschueren, S. Hol, D.C. Cobben Radboud University Medical Centre, Radiation Oncology, Nijmegen, The Netherlands Dr. Bernard Verbeeten Instituut, Radiation Oncology, Tilburg, The Netherlands Purpose or Objective: Voluntary moderate deep inspiration breath-hold (vmDIBH) is widely used for patients with left sided breast cancer. The purpose of this study was to investigate the utility of vmDIBH in local and locoregional radiation therapy (RT) for patients with right-sided breast cancer. Material and Methods: For fourteen patients with right-sided breast cancer, forward IMRT plans were calculated on freebreathing (FB) and vmDIBH CT-scans, for localas well as locoregional breast treatment, with and without internal mammary lymph nodes (IMN). We compared dose volume parameters to estimate the reduction in the risk of radiation pneumonitis, the influence on pulmonary lung function tests and the risk of secondary lung cancer with the use of vmDIBH. Results: For local breast treatment, no relevant reduction in mean lung dose (MLD) was found. For locoregional breast treatment without IMN, the average MLD reduced from 6.5 to 5.4 Gy (p<0.005) for the total lung and from 11.2 to 9.7 Gy (p<0.005) for the ipsilateral lung. For locoregional breast treatment with IMN, the average MLD reduced from 10.8 to 9.1 Gy (p<0.005) for the total lung and from 18.7 to 16.2 Gy (p<0.005) for the ipsilateral lung. We also found a reduction in mean heart dose between 0.6 and 2.6 Gy in four patients; with a mean of 0.4 Gy for all 14 patients together (p=0.07). We estimate that 1 out of 100 patients will not develop radiation pneumonitis when breath-hold is applied during locoregional right-sided breast cancer treatment. For eversmoking women, the risk of secondary lung cancer might also be reduced by vmDIBH. Conclusion: Breathing adapted radiation therapy in patients with left-sided breast cancer is becoming widely introduced. As a result of the slight reduction in lung dose found for

PO-0695: Lobectomy vs Stereotactic Ablative Radiotherapy in NSCLC:a multicentric series in four centers

S325 ________________________________________________________________________________ Patients were treated consecutively in the University Hospitals of Leuven between 2005 and 2014 and their data were retrospectively retrieved. PORT MPM patients were treated with RT doses up to 64 Gy in 2-Gy fractions. PORT NSCLC were treated with RT doses up to 60 Gy in 2-Gy fractions. Non-surgical patients were treated with RT doses up to 66 Gy in 2.75 Gy sequentially with chemotherapy or up to 70 Gy in 2 Gy fractions concurrently with chemotherapy. Dyspnea scores (CTCAE 4.03) before and after RT were retrieved and delta dyspnea was calculated as the difference between the dyspnea after RT (worse at any time point) and before RT. For every patient, 2 CT scans were retrieved: 1) CT0: a free breathing planning CT scan; 2) CT3M: deep inspiration breath-hold diagnostic follow up CT scan 3-6 months after the end of RT. CT0 and CT3M were non-rigidly co-registered in MIM. Differences in Hounsfield Unit (delta HU=HU3M-HU0) were represented as the slope of the dosedependent delta HU between 0 and 20 Gy (expressed in delta HU/Gy). Primary endpoint was delta dyspnea >= 2. Univariate and multivariate logistic regression analysis were performed in order to identify significant predictors of delta dyspnea >= 2. A p-value of < 0.05 was considered statistically significant.

A.201 - Dosimetric benefits and reproducibility of DIBH tecnique guided by an optical system

Results: The projected 2D CT bin areas for the 5 patients had a mean (standard deviation) area of 4.12(0.35), 5.17(0.40), 2.99(0.34), 9.28(0.52) and 3.96 (0.35) cm2. This is compared to the MR contoured areas of 5.02 (0.45), 7.13(0.67), 2.63(0.41), 7.52(0.57) and 4.07(0.41) cm2 (Figure 1). While there are differences that may be attributed to binning errors from 4D CT reconstruction and intra-observer variations, contours from real time MRI do not appear to be systematically biased on target area compared to the CT contours. Figure 1. Mean area for five lung tumors on CT, MRI and MIP. Error bars represent standard deviation.

Adjuvant whole pelvic radiotherapy in 43 patients with uterine serous cancer: outcome and patterns of failure

AIMS AND BACKGROUND Uterine serous cancer is associated with a poor outcome and poses a therapeutic challenge. We retrospectively evaluated the experience of the Radiotherapy Department of the University of Florence. METHODS Forty-three patients with stage I-III uterine serous cancer underwent surgery with (18 patients, group 1) or without complete surgical staging (25 patients, group 2) followed by adjuvant whole pelvic radiotherapy alone or combined with vaginal brachytherapy (in 35 and 8 cases, respectively). The median dose delivered with whole pelvic radiotherapy was 50 Gy (range, 45-56) and for brachytherapy was 20 Gy (range, 20-30). RESULTS Actuarial overall survival and disease-free survival rates at 5 years were 62.5% and 61%, respectively. Local failure was observed in 17 patients (39.5%) and distant metastasis in 10 (23.2%). Nine patients had both local failure and distant metastasis, which had developed concurrently in 7 cases. Isolated abdominal failure occurred in 4 cases (9.3%). Local relapse was noted in 22.2% of patients in group 1 compared to 52% in group 2. A trend towards a better 5-year overall survival (67.2% vs 58%), disease-free survival (63% vs 59%) and local control (70% vs 59%) was observed in group 1 than group 2, although the difference between the two groups failed to reach statistical significance. CONCLUSIONS Given the patterns of failure of patients with uterine serous cancer, adjuvant whole pelvic radiotherapy may be a reasonable approach, although novel integrated strategies are needed because the results achieved remain disappointing. Adjuvant whole pelvic radiotherapy might improve overall survival, disease-free survival and local control in complete surgically staged patients, but further investigations are required.