Abstract Book

S730

ESTRO 37

Results Median age was 53, 9 years (range 23-90). Classification with VNPI in all patients was high risk depending on: size tumor, grade tumor, age patient and margins. After median follow-up of 112 months, recurrence occurred in 18 patients (10,3%), including 5 patients DCIS ipsilateral recurrence (2,8%), 6 patients ipsilateral invasive carcinoma recurrence (3,5%), 3 patients locoregional recurrence (1,7%) and 4 patients distant metastases (2,3%). Predictive factors for recurrence were identified: presentation, margins and endocrine therapy; clinical presentation (p=0,002), close (<1-9mm) margins (p=0,01) and endocrine adjuvant therapy (p=0,05) were associated to recurrence by univariate analysis. Other factors were analyzed but were not significant in statistical analysis. The 5-year overall survival (OS) was 96.55%. Conclusion Clinical presentation, close margins in tumor and endocrine treatment was identified as predictive factors of recurrence for DCIS treated with mastectomy. In this cases we need consider evaluate radiotherapy as local adjuvant treatment. EP-1334 The role of coronary CT angiography for early detection of heart coronary disease after breast EBRT N. Jornet 1 , D. Viladés-Mendel 2 , M. Lizondo 1 , M. Fuentes 3 , R. Leta 2 , P. Carrasco de Fez 1 , A. Latorre-Musoll 1 , P. Delgado 1 , A. Ruiz-Martinez 1 , T. Eudaldo 1 , J. Isern 3 , M. Ribas 1 1 Hospital de la Santa Creu i Sant Pau, Medical Physics, Barcelona, Spain 2 Hospital de la Santa Creu i Sant Pau, Cardiology, Barcelona, Spain 3 Hospital de la Santa Creu i Sant Pau, Radiation Oncology, Barcelona, Spain Purpose or Objective Higher risk for the development of cardiovascular disease has been described for left breast cancer patients being treated with RT when compared to normal population. The aim of this cross-sectional study was, by the use of coronary CT angiography, to look for possible correlations between the extension and severity of the coronary lesions with different heart dosimetric dose-volume parameters. Material and Methods 13 left-sided breast cancer patients treated with RT (3D- CRT or IMRT) with mean doses (D mean ) to the heart ranging from 5 to 20 Gy were selected. All, except of 3 patients, were asymptomatic for heart disease at the study time (3 years post RT). The mean age was 62 years (SD 11). Only 4 presented Hypertension (HT). None had received cardio toxic chemotherapy. A control group of 19 non-oncologic women matched in age, HT and smoking habits but with slightly higher Hypercholesterolemia and Diabetes Mellitus (DM) was used. For these two groups of patients a ECG-gated prospective coronary CT angiography (CTA) with a 256-slice CT scan was performed. On CT images the Segment Involvement Score (SIS), Segment Stenosis Score (SSS), Coronary Artery Disease Reporting and Data System classification (CAD-RADS) and incidence of ostial lesions were obtained. Patient age and cardiovascular risk factors (HT, Hypercholesterolemia, DM and smoking habits), treatment technique and RT heart dosimetric indexes (V30, V25, D mean and D2) were collected. Correlations between CTA findings (SIS, SSS and CAD- RADS) and RT heart dosimetric indexes (V30, V25, D mean and D2) were evaluated. Differences in SIS and SSS between the study and control groups were analysed. Results This study shows that this series of irradiated patients have a higher extension and severity of asymptomatic CAD than the control group. Being the SIS for control group 1.9 and the irradiated group 2.4, SSS 0.43 and 1.42

respectively, with a tendency to significance (p=0.11). Fig.1 shows CTA images for one patient. Table1 shows the correlations between CTA findings and dosimetric heart indexes. SIS, SSS and CAD-RADS correlate with V25 and V30 while D mean correlates only with SSS and D2 does not shown any correlation. No correlations were found for ostial lesions. SSS index correlated with D mean larger than 10Gy (P=0.07).

Conclusion The results of this cross-sectional study are a proof of concept that CTA is a useful to detect CAD after left breast irradiation, showing that for the irradiated group, there is a tendency to significance in the number and severity of coronal lesions when compared with the control group. For the irradiated group V30 looks as a better surrogate for CAD than Dmean. In view of these results, a prospective longitudinal study including a larger number of patients with base-line pre-radiotherapy imaging is being designed. Longer follow up is needed to establish if these early image findings correlate with future clinical manifestations. EP-1335 Efficacy and Safety of hypofractionated loco- regional radiotherapy for breast cancer patients. M. Caubet 1 , P. Bontemps 1 , A. Anota 2 , F. Boulbair 1 , Y. Hammoud 1 , K. Peigneaux 3 , G. Créhange 3 , B. De Bari 1 1 Hôpital Univ. Jean Minjoz CHU Minjoz Jeans & Belfort- Montbéliard Hospital, Radiation Oncology, Besançon, France 2 Methodology and Quality of life in Oncology Unit, Medical Oncology, Besançon, France 3 Georges François Leclerc Centre, Radiation Oncology, Dijon, France Purpose or Objective To retrospectively evaluate efficacy and safety of hypofractionated locoregional radiotherapy (HLRT) in breast cancer (BC) patients. We compared this schedule with a population of patients treated, in the same period, with hypofractionated radiotherapy on the breast/wall chest only (HRT). Material and Methods Clinical charts of patients with a biopsy-proven BC treated with postoperative HLRT (n= 275, 63%) or HRT (n=