ESTRO 37 Abstract book

S730

ESTRO 37

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).

Results With a median follow-up of 22.5 months (range 5-33), 1p (0.7%) presented local relapse, 3p (2.1%) regional nodal relapse and 4p (2.9%) distant metastases including the 2p that presented stage IV at diagnoses. At date of last follow-up, 136p (97.1%) are alive without tumor, 3p (2.1%) alive with tumor and 1p (0.7%) has died because of breast cancer. Actuarial 3-year locoregional free survival (LRFS), disease free survival (DFS) and overall survival (OS) were 89.9%, 87.3% and 99% respectively. Acute toxicity was null or mild. Nearly all patients (135p, 96.4%) experienced skin toxicity: grade 1 = 89p (63.6%), grade 2 = 43p (30.7%) and grade 3 = 3p (2.1%). Other toxicities: arm lymphedema in 8p (5.7%): grade 1 = 6p (4.3%) and grade 2 = 2p (1.4%); acute pneumonitis in 2p (1.4%), both grade 1. Conclusion Hypofractionated schedules for whole breast and RNI is feasible and well tolerated. Longer follow-up is needed to address the observed outcomes. EP-1333 Predictive Factors of Recurrence after Mastectomy for Ductal Carcinoma in situ C. De la Pinta Alonso 1 , E. Fernández-Lizarbe 1 , A. Muriel 2 , B. Pérez Mies 3 , R. Hernanz De Lucas 1 , M. Martín Sánchez 1 , A. Montero Luis 4 , S. Sancho García 1 1 Hospital Ramon y Cajal, Radiation Oncology, Madrid, Spain 2 Hospital Ramon y Cajal, Statistical Department, Madrid, Spain 3 Hospital Ramon y Cajal, Pathological Department, Madrid, Spain 4 HM Madrid, Radiation Oncology, Madrid, Spain Purpose or Objective Mastectomy without radiotherapy is the standard of care in our institution for high-risk patients in Van Nuys Prognostic Index (VNPI) classification in Ductal carcinoma in situ (DCIS). The aim of this study is to identify predictive factors for tumour recurrence in this group of patients. Material and Methods From 2000 to 2014, 174 patients with DCIS treated by mastectomy were retrospectively studied. Tumor characteristics and treatment-factors were tested for influence on tumor recurrence. We analyzed overall survival (OS 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.