ESTRO 38 Abstract book

S1174 ESTRO 38

CI95% [58.4-91.1] and 57.1%, IC 95% [40.8-79.8], (p = 0.0026). Similar results were found for 5-year PFS: 64.5% CI95% [49.5-84.1] for patients aged from 70 to 85 years, and 51.6% CI95% [35.8-74.5] for patients over 85 years old, respectively (p = 0.014). The 5-year OS was also statistically different according to the CCI score: 70.8% CI95% [57.0-87.9] for a CCI of 0, and only 59.8% CI95 % [42.4-84.3] for patients with a CCI Score ≥ 1 (p = 0.039). 10.6% of the patients had no toxicities; of those who experienced side effects, the most frequent were grade 1 and 2 radio dermatitis (59%). Late toxicities were observed in 39.4% of the patients, mostly of grade 1 and 2. No late toxicity of grade ≥ 3 was observed. Conclusion Exclusive radiation therapy for non-metastatic BC in older women is feasible and well-tolerated when adapted techniques are used, but the prognostic is poor in comparison with younger patients as the outcome is strongly impacted by age and comorbidities. EP-2123 APBI with Interstitial Brachytherapy versus Whole-Breast Irradiation for Early-Stage Breast Cancer A. Figueiredo 1 , D. Delgado 1 , J. Santos 1 , A. Florindo 1 , V. Purpose or Objective To report long-term outcomes of adjuvant accelerated partial breast irradiation (APBI) with multicatheter interstitial high dose rate brachytherapy (HDR BT) at our department and compare these results to adjuvant whole- breast irradiation (WBI) with 3D external beam Between 2004 and 2017, 25 patients (pts) with early-stage breast cancer (pT1-2 (≤ 30 mm) pN0) were treated with interstitial HDR BT after breast-conserving surgery. The characteristics of these pts are presented in table 1. The prescribed dose was 8 fractions of 4 Gy, twice a day, in all patients. A propensity-score matching approach was performed to compare the survival outcomes of APBI to WBI using a database of 260 pts treated with adjuvant WBI at our center. radiotherapy (EBRT). Material and Methods Mendonça 1 , M. Jorge 1 , M. Filomena de Pina 1 1 Centro Hospitalar Lisboa Norte, Serviço de Radioterapia, Lisboa, Portugal

Results During the study period, 233 patients were treated with BCS/oncoplastic surgery and IORT: 218 (93.6%) patients as monotherapy, 12 (5.1%) patients as a boost, and 3 (1.3%) patients were treated out of protocol, accepted by the Tumor board because of comorbidities, elderly and social issues. Patients: mean age 67 y.o. (48.2-88.9) Histology: IDC 205 (88.0%), ILC 8 (3.4%), other subtypes of IDC 20 (8.6%). ER + 225 (91.0%). HER-2/neu 3+ or SISH+ 7 (3.0%).Ki 67 >15% 160 (68.7%). Surgery: average IORT time 11.2 min (9.5-16.5), average operation time 150.5 min (65-315). BCS 219 (94.0%), oncoplastic surgery 14 (6.0%). SLNB 224 (96.1%): positive (micrometastases or macrometastases) 64 (28.3%) Reinterventions 20 (8.6%): rescission 6 (2.6%), MRM 1 (0.4%), ALND 5 (2.1%), complications 8 (3.5%). Adjuvant therapy: chemotherapy 50 (21.5%), hormone- therapy 220 (94.4%), EBRT 65 (27.9%). Oncologic outcomes: local recurrences 3 (1.3%). Metastases (liver, bone) 2 (0.9%). Major complications: RTOG 3-4: 2 (1.0%), seroma that required >3 drainages 2 (0.9%), infection that required intravenous antibiotic or surgical drainage 4 (1.7%), hematoma that required surgical drainage 4 (1.7%), fistula that required surgical fixing 4 (1.7%), palpable fibrosis 14 (6.1%). Median follow up: 857.5d (215-1210). Cancer related mortality: 0. Non cancer related mortality 7 (3.0%). Conclusion IORT is a feasible technique with several benefits and good short-term outcomes in selected patients. EP-2122 Outcome of exclusive RT for BC in older women according to age and comorbidity: A retrospective study W. Lorraine 1 , K. Cao 1 , M. Carton 2 , A. Fourquet 1 , Y. Kirova 1 1 Curie institute, Radiotherapy, Paris, France; 2 Curie Institute, Biostatistics, Paris, France Purpose or Objective Older women with breast cancer (BC) are less likely to receive standard care. In specific circumstances when surgery is omitted as first step of treatment, RT seems to be an adequate local solution as a non-invasive option. The aim of this study was to assess the efficacy, tolerance and impact of comorbidities on outcomes in older women treated by exclusive radiation therapy (RT) for non- metastatic breast cancer (BC) Material and Methods We studied retrospectively women aged ≥ 70 years at diagnosis who received exclusive conformational RT for their BC between 2003 and 2012 in our Department. We calculated the Charlson Comorbidity Index (CCI) for each patient. Conventionally fractionated or hypofractionated RT was prescribed at the physician’s discretion in a case- by-case basis. We analysed overall survival (OS), progression free survival (PFS), and specific survival (SS). Acute and late toxicities were assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v3.0. Results On sixty-six patients included, median age was 84.8 years [71.3-91.7]. Most patients had a CCI score ≥ 1 (n = 41, 62.1%). Nearly half (47%) had T1-2N0M0 BC (n = 31). Surgery was omitted in most cases because of patients’ refusal (54.2%) and/or patients’ comorbidities (41.7%). Most of them (87.9%) were treated by hypofractionated RT and received hormonal therapy for their HR+ HER2- BC (84.8%). With a median follow-up of 6.8 years [1.3-12.3], OS, SS and PFS at 5 years were 65.5% CI95%[54.1-79.3], 86.3% CI95% [77.2-96.4]), and 58.4% CI95%[46.9-72.7], respectively. Five-year OS was statistically different according to age younger or older than 85 years: 72.9%