ESTRO 38 Abstract book

S721 ESTRO 38

eligible if affected by T1-T3 invasive BC, with no or limited axillary involvement. The scheme was offered to elderly women (age threshold of 65 years) and to those with commuting difficulties or disabling diseases. Results Median age was 76 (45.5-86.4) years. Median follow-up was 24.6 (6.2-65.7) months. Most of BC were T1 (77%), while the remaining were T2 (22.2%), T3 (0.4%). Axillary status was negative in 68.3%, minimally involved in 14.4% (pN1) and not assessed in 17.3% of the cases (Nx). Most of the women received hormonal therapy (84%), while 10.7% received chemotherapy. The schedule was delivered either with three-dimensional conformal RT (n=133) or with intensity-modulated RT (n=138). No statistically significant difference was observed between the two techniques in terms of toxicity and efficacy. For 271 patients, maximum acute toxicity at the end of RT was as follows: grade (G) 1, 2 and 3 erythema in 63%, 7% and 0.4% of patients, respectively. G2 edema was detected in 10% of patients. Desquamation occurred in 4.4% as G1 and 1.5% as G2 of cases. At median 2-year follow up, LENT-SOMA assessment was available for 137 patients. Fibrosis (G1 and G2 in 46.7% and 9.5%, respectively) and skin changes (G1 and G2 hyper- or hypo- pigmentation in 29.2% and 2.2% respectively, G1 and G2 telangiectasia in 3 patients) were observed. A minority complained pain of G1 (n=26) and G2 (n=2) intensity. Two-year oncologic outcome was assessed for 257 patients. At the last follow-up examination, 244/257 patients were alive and free from any event. There was a total of 5 (1,9%) isolated locoregional recurrences: 4 involved the breast and 1 the axillary lymph nodes. Three women experienced a second cancer in other sites. Two died for other reasons (at 3 years, disease-free survival and overall survival were 100% and 99%) Predictive factors for toxicity were breast volume >500 cm 3 for acute toxicity, while none was correlated with severe late toxicity. Conclusion Toxicity was mild and acceptable with high patients’ satisfaction. Local control was acceptable, none died of BC and overall survival was 99% at 3 years. EP-1316 Radiotherapy in elderly breast cancer patients with hormone therapy: A population-based study D. Medenwald 1 , A. Glowka 1 , D. Vordermark 1 , K. Medenwald 1 1 Martin Luther University Halle-Wittenberg, 1\tDepartment of Radiation Oncology, Halle/Saale, Germany Purpose or Objective For breast cancer patients above an age of 70 with a stage of pT1 and N0 receiving hormone therapy the value of additional radiotherapy has been challenged. The objective of this study is to analyze treatment patterns and outcomes of elderly female breast cancer patients above an age of 70 years in the general population. Material and Methods patients. This data set incorporates data on incident cancer cases and contains information on stage, histological features, and received treatment and survival outcomes. For this study, we excluded patients where the diagnosis of breast cancer was only available from autopsy/death certificates. Additionally, we only considered data from states with a high coverage of newly diagnosed cases (>70%, East Germany including Berlin, Bavaria, Rhineland-Palatine, Schleswig-Holstein). For subsequent analyses, we considered female breast cancer cases with recorded operative and hormone treatment, and histological confirmation of the cancer diagnosis. For survival analyses, we used Cox proportional hazard models where we computed hazard ratios (HR) with respective 95 confidence intervals (CI). In order to respect

Conclusion A strong correlation between the dose to the heart, LV and LAD was found. This correlation could allow us estimating the dose in LAD and LV through the MHD, being possible to avoid the contouring of the LAD and LV. We are currently working on the validation of a prediction model for acute/ischemic cardiac events in these patients. EP-1315 The FAST approach as adjuvant whole breast irradiation for frail breast cancer patients M.A. Zerella 1,2 , S. Arculeo 1,2 , E. Miglietta 1 , A. Casbarra 1,2 , S. Dicuonzo 1 , V. Dell'Acqua 1 , M.A. Gerardi 1 , A. Morra 1 , C. Fodor 1 , F. Cattani 3 , V.E. Galimberti 4 , P. Veronesi 2,4 , R. Orecchia 5 , M.C. Leonardi 1 , B.A. Jereczek-Fossa 1,2 1 European Institute of Oncology IRCCS, Division of Radiation Oncology, Milan, Italy ; 2 University of Milan, Department of Oncology and Hemato-oncology, Milan, Italy ; 3 European Institute of Oncology IRCCS, Unit of Medical Physics, Milan, Italy ; 4 European Institute of Oncology IRCCS, Division of Breast Surgery, Milan, Italy ; 5 European Institute of Oncology IRCCS, Scientific Directorate, Milan, Italy Purpose or Objective To evaluate the outcome in terms of toxicity, local control and survival of elderly breast cancer (BC) patients treated with adjuvant once-weekly hypofractionated radiotherapy (RT). Material and Methods From 7/2011 to 4/2018, 271 BC patients were given received 5.7 Gy once a week for 5 weeks to the whole breast, without the boost to the tumor bed, after breast- conserving surgery. Data were extracted from a dedicated databank for research projects called “Adjuvant radiation treatments with intensity-modulated radiotherapy and/or hypofractionated schedules for breast cancer” which was notified to the IEO Ethical Committee. Patients were