ESTRO 36 Abstract Book

S91 ESTRO 36 2017 _______________________________________________________________________________________________

To examine 5-year rates of local control for breast cancer patients with local relapses after second conservative surgery and accelerated partial breast irradiation (APBI). Material and Methods Eligibility included local relapses of breast cancer <3 cm in size after lumpectomy with negative surgical margins. The APBI dose delivered was 34 Gy in 10 twice-daily fractions over 5 days for high-dose-rate. This analysis focuses on ipsilateral breast recurrence(LBR), regional recurrence (RR), and distant metastases (DM), disease- free and overall survival. Results The median follow-up was 49.6 months (5-98m). Fithty two patients (p) were accrued from Sep 2008 to August 2015. Histology: Intraductal carcinoma 15 p, Ductal carcinoma 31 p, Lobulillar carcinoma: 5 p; Papilar carcinoma : 1p; 50 p had T1 tumors and 2 p had T2. Seventy-five percent were estrogen receptor and/or progesterone receptor positive. There have been 4 local breast recurrences, 1 regional recurrence (RR), and 1 distant metastases (DM), The 5- year Local Recurrence Disease Free rate was 91.6%. The 5-year Disease Free Survival and Overall Survival rates are 87 % and 100%, respectively. Conclusion This prospective trial studying APBI in local relapses of Breast Cancer show a high local control, so this treatment is an real option to Mastectomy in these patients OC-0181 Long-term clinical and cosmetic outcomes of high-dose-rate brachytherapy for early breast cancer F. Arcidiacono 1 , L. Chirico 1 , M. Italiani 1 , P. Anselmo 1 , M. Casale 1 , L. Draghini 1 , F. Trippa 1 , S. Fabiani 1 , M. Basagni 1 , E. Maranzano 1 1 "S.Maria" Hospital, Radiotherapy Oncology Centre, Terni, Italy Purpose or Objective To report long-term clinical and cosmetic outcomes of partial breast irradiation (PBI) with 192 Ir high-dose-rate brachytherapy (HDR-BRT) in early breast cancer patients. Material and Methods From May 2005 to February 2012, 124 patients undergoing conservative surgery for early breast cancer were recruited in a phase II trial of exclusive 192 Ir HDR-BRT. Inclusion criteria were: age >40, PS 0-2, unifocal invasive ductal cancer, intraductal cancer component <25%, negative axillary nodes and tumor size ≤2.5 cm. Treatment schedule was 4 Gy twice a day for 4-5 days, up to a total dose of 32 Gy in 8 fractions with a minimum interval between daily fractions of at least 6 hours. Late toxicity was graded at each follow-up visit according to RTOG/EORTC scoring criteria and cosmetic outcomes according to Harvard criteria and scored as excellent, good, fair and poor. Results Median age was 67 years (range, 42-85). There were 10 (8%) pT1a, 38 (31%) pT1b, 68 (55%) pT1c and 8 (6%) pT2. Estrogenic and progestinic receptors were positive in 113 (91%) and 104 (85%) cases, respectively. 110 (88%) and 15 (12%) patients received adjuvant hormonal therapy and chemotherapy, respectively. Median follow-up was 77 months (range, 8-132). 1 (0,8%) isolated out-field breast relapse occurred 109 months after HDR-BRT. 1 (0,8%) patient developed contralateral breast cancer and another one (0,8%) regional relapse in axillary node. 13 (10,5%) patients reported a second primary cancer. 5- and 10-year overall survival and cancer specific free survival were 95% and 88%, 100% and 98%, respectively. At last follow-up, 114 (92%) patients were alive without disease and 3 (2,5%) with systemic disease. 10 (8%) patients died: 1 (0,8%) for breast cancer, 2 (1,6%) for other cancers and 7 (5%) for other causes. Cosmetic outcomes were excellent in 102 (82%), good in 11 (9%), fair in 8 (6%) and unknown in 3 (2,5%) patients. Late skin

toxicity was registered in 29 (23,4%) patients, grade 1-2 in 28 (22,5%), grade 3 in 1 (0,8%). Late toxicity was significantly related to the skin administered doses (≤ 55% vs. > 55%, P < 0.05). Conclusion PBI delivered with 192 Ir HDR-BRT in selected breast cancer patients was associated to high local control and survival with excellent cosmetic outcomes. An appropriate patient selection and skin dose ≤ 55% provided optimal clinical outcomes. OC-0182 2nd breast conserving therapy with interstitial BT vs mastectomy for treatment of local recurrences V. Smanykó 1 , N. Mészáros 1 , M. Ujhelyi 2 , G. Stelczer 1 , T. Major 1 , Z. Mátrai 2 , C. Polgár 1 1 National Institute of Oncology, Center of Radiotherapy, Budapest, Hungary 2 National Institute of Oncology, Center of Surgery, Budapest, Hungary Purpose or Objective To compare the clinical outcomes of second breast conserving therapy (BCT) with perioperative high-dose- rate (HDR) interstitial brachytherapy (iBT) versus salvage mastectomy (sMT) for the treatment of ipsilateral breast tumor recurrences (IBTRs). Material and Methods Between 1999 and 2016, 92 patients who presented with an IBTR after previous BCT were salvaged either with reexcision and perioperative HDR multi-catheter iBT (n=35) or sMT (n=57). In the BCT + HDR iBT group a median of 7 (range: 4-23) catheters were implanted intraoperatively. A total dose of 22 Gy in 5 fractions of 4.4 Gy was delivered to the tumor bed with a margin of 1-2 cm perioperatively on 3 consecutive days. Similar proportion of patients received adjuvant chemotherapy in the two groups (17% after BCT + HDR iBT vs 21% after sMT) and/or hormonal treatments (71% vs 70%, respectively). Five-year oncologic outcomes (including ultimate local tumor control, regional tumor control, disease-free survival [DFS], cancer specific survival [CSS], and overall survival [OS]) were estimated by the Kaplan-Meier method. Survival curves were compared with the log-rank test. Results Mean follow up time was 63 months (range: 2-183) in the BCT + HDR iBT group vs 30 months (range: 4-164) in the sMT group. The mean diameter of IBTRs was 16.8 mm (range: 2-70) vs 24.5 mm (range: 2-60), respectively. There was no significant difference in any other patient (e.g. age, menopausal status) or IBTR related (e.g. grade, vascular invasion, margin status, receptor status) parameters between the two groups. Three out of 35 (8.6%) and 7 out of 57 (12.3%) second local recurrences occurred in the BCT + HDR iBT and the sMT group, respectively. The 5-year actuarial rate of second local recurrence was 7.4% after BCT + HDR iBT vs 17.5% after sMT (p=0.11). The respective 5-year rates of regional recurrence were 7.2% vs 5.3% (p=0.17). The 5-year probability of DFS, CSS, and OS were 69.7% vs 73.5% (p=0.79), 74.9% vs 80.5% (p=0.72), and 74.9% vs 69.6% (p=0.73), respectively. At the time of analysis data on cosmetic results were available for 31 patients (88.6%) in the BCT + HDR iBT group. Among these, 3 (9.7%), 16 (51.6%), 5 (16.1%), and 7 (22.6 %) patients had excellent, good, fair, and poor cosmetic results. Grade 2 and 3 late skin toxicity occurred in 2 (5.7%) and 1 (2.9%) patients, while grade 2 and 3 fibrosis developed in 9 (25.7%) and 1 (2.9%) patients. Asymptomatic fat necrosis was detected in 11 (31.4%) women. Conclusion Second BCT + HDR iBT is a safe and feasible option for the management of IBTRs resulting similar 5-year oncologic outcomes compared to standard sMT. HDR iBT may