Abstract Book

S732

ESTRO 37

metastatic disease in 21 Gy arm. The cumulative 5 yy LRFS, DFS and OS were 96.7%, 96% and 96.4%, respectively. No significative difference in LRFS, DFS and OS was detected in 18 Gy arm vs 21 Gy arm (5 yy LRFS 96.8% vs 97.8% - P=0.6, 5 yy DFS 96.8% vs 96.6% - P=0.266, 5 yy OS 95.8% vs 96.9%- P=0.83). At definitive histological examination 154 pts presented DCI and 15 pts other histology (none LIC or DCSI), 19 pts positive nodes, 4 pts positive or close margins and 33 pts underwent to adjuvant chemotherapy. As regards hystology (DCI vs other) and molecular subtypes (Luminal A, Luminal B, HER2+, basal like) no significant differences (P=0.139 and 0.238, respectively) were detected in the two groups (18 Gy vs 21 Gy). Grouping the patients according to ASTRO guidelines for accelerated partial breast irradiation, 114 (67%), 38 (22%) and 17 (10%) pts resulted suitable, cautionary and unsuitable, respectively. As regards toxicity, in 9 patients (3 and 9 in 18 Gy and 21 Gy arm, respectively) breast ultrasound showed liponecrosis. Conclusion Although 21 Gy remains the standard dose for exclusive IORT in breast cancer, from our data emerged no differences for 18 Gy group. A longer follow up and further randomized trials are necessary to confirm these results. EP-1338 No Axillary Dissection Among Women With Invasive Breast Cancer and Sentinel Node wit Macrometastasis I. García Ríos 1 , A. Fernández Forné 1 , I. Domenech Navarro 1 , M.J. Garcia Anaya 1 , M. Pamos Ureña 1 , R. Correa Generoso 1 , R. Ordoñez Marmolejo 1 , A. Otero Romero 1 , A. Román Jobacho 1 , J. Gomez Millán 1 , J.E. Montes García 1 , J.A. Medina Carmona 1 1 HOSPITAL UNIVERSITARIO VIRGEN DE LA VICTORIA, Radiation Oncology, Málaga, Spain Purpose or Objective Clinical practice has changed since publication of the ACOSOG Z0011 trial. Recently have been reported, 10- year overall survival for patients treated with sentinel lymph node dissection alone was noninferior to overall survival for those treated with axillary lymph node dissection. These findings do not support routine use of axillary lymph node dissection in this patient population based on 10-year outcomes. The Breast Cancer Committee of our hospital approved the implementation of the protocol ACOSOG Z0011. The primary end point was to determine disease free survival, defined as the time from diagnosis to the first documented recurrence of breast cancer. Breast cancer recurrence was categorized as locoregional disease (tumor in the breast or ipsilateral supraclavicular, subclavicular, internal mammary or axillary nodes) or distant metastases. These morbidities have been reported. Material and Methods

adenopathy, negative axilla evaluated by ultrasound, and SLNs positive for metastatic breast cancer documented by or hematoxylin-eosin staining on permanent section. Women were ineligible if they had 3 or more positive SLNs (they received axillary lymph node dissection in the second time) and patients candidates to mastectomy. All women received whole-breast opposing tangential-field radiation therapy and axillary radiotherapy included levels I and II, but no levels III and IV. All patients. The use of adjuvant systemic treatment was applied at the discretion of the treating multidisciplinary team. Results From February 2011 to December June 2017, 148 patients met the inclusion criteria and were selected for analysis 114 patients with positive SLNs and at least one year since end treatment with Radiotherapy. The patients were treated with Hypofractionated radiation therapy (HFRT) with total dose of 40,05 Gy in 15 fractions over 3 weeks or once-weekly hypofractionated (32.5 Gy in 5 fractions /6.5 Gy once a week or 28,5 Gy in 5 fractions (5,7 Gy once a week). All patients had invasive breast carcinoma and 1 or 2 sentinel node metastasis. The average tumor size was 2 cm (0.6 to 3.7 cm). The size tumor: pT1b: 10,5%, pT1c: 48.2%, pT2: 40.4% pT3 0.9% (1 patientes). Median number of excised lymph nodes was 2 and sentinel node with metastasis was 1. Phenotipe was: Luminal A 38,6%, luminal B her2 – 43%, luminal B her2 + 10,5%, Triple negative 6,1% , Her2 + no luminal: 1,8%. At a median follow-up of 49 months, no regional recurrence was observed, and one recurrence in a different breast quadrant was presented. The 6 year disease free survival was 90.2% and global survival 90.3%.

Conclusion In patients with limited SLN metastasis breast cancer treatment with breast conservative surgery and radiation therapy, the use of SLND and radiotherapy to levels I and II, avoiding the lymphadenectomy, provides excellent locoregional control and survival. The results of this study are limited by the short follow up EP-1339 Evaluation of Sleep Quality in Breast Cancer Patients Receiving Radiation Therapy E. Yirmibesoglu Erkal 1 , S. Karabey 1 , G. Aksu 1 , H. Erkal 2 1 Kocaeli University, Department of Radiation Oncology, Kocaeli, Turkey 2 Sakarya University, Department of Radiation Oncology, Sakarya, Turkey Purpose or Objective The etiology of sleep disturbances in breast cancer patients is multi-factorial. Demographic, environmental and lifestyle factors, psychological disturbances and comorbid disorders have been pointed to as main factors contributing for sleep disturbances. Cancer-related treatments, and their wide range of side effects, are other important feature frequently associated with the occurrence of sleep disturbances. In addition, the

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Inclusion criteria: adult women with histologically confirmed breast carcinoma T1-T2, no palpable