S634 ESTRO 36 _______________________________________________________________________________________________
considered as satisfactory or very satisfactory in 90% of cases. Lymphedema occurred in 17.1% of patients (minor: 14.4%, severe: 2.7%), related to axillary radiotherapy (p<0.001) and obesity (p=0.017). Long-term pulmonary toxicity reached 4% and was related to the irradiated volume. Among the 95 patients with pulmonary comorbidities, 9% experienced increased respiratory symptoms after radiation therapy; it is not possible to distinguish between radiation toxicity and respiratory disease evolution. Late cardiac events were reported in 21 patients (2.7%), of which 17 had received anthracyclines and 9 trastuzumab. Three patients developed ischemic heart disease, within 5 to 7 years after radiotherapy; all of them had received anthracyclines and were irradiated at the left chest wall and LN, but also had many cardiovascular risk factors (2 to 4). Mean heart doses were 4.35Gy (2.1-6.6) and 1.7Gy (0.52.9) and mean ipsilateral lung doses were 13.9Gy (10.817) and 12.4 (8.6-16.1), in case of left and right chest wall and LN irradiation respectively. Conclusion This series shows that our PMERT technique is well tolerated at short and long term. EP-1166 Patterns of post-operative radiotherapy in breast cancer patients after neoadjuvant chemotherapy K.M. Lopes1, T.B. De Freitas1, H.A. Carvalho1, A.A. Pereira2, S.B. Silva2, S.R. Stuart1, M.S. Mano2, J.R. Filassi3, G.N. Marta4,5 1 Faculdade de Medicina da Universidade de São Paulo, Radiation Oncology, Sao Pailo, Brazil 2 Faculdade de Medicina da Universidade de São Paulo, Clinical Oncology, Sao Pailo, Brazil 3 Faculdade de Medicina da Universidade de São Paulo, Breast Division, Sao Pailo, Brazil 4 Hospital Sírio-Libanês, Radiation Oncology, São Paulo, Brazil 5 Instituto do Câncer do Estado de São Paulo ICESP Faculdade de Medicina da Universidade de São Paulo, Radiation Oncology, Sao Paulo, Brazil Purpose or Objective Neoadjuvant chemotherapy (NCT) has the same results as adjuvant chemotherapy in regard to disease-free survival and overall survival and may also allow breast conserving surgery for patients with locally advanced breast cancer. Indications for adjuvant radiotherapy (RT), as well as treatment targets after NCT are not yet well established. The purpose of this study is to evaluate locoregional RT indications and treatment targets in breast cancer patients submitted to NCT. Material and Methods Retrospective study of 523 patients treated between March 2010 and April 2015 that were submitted to NCT and received post-operative RT. Demographics, tumor and treatment characteristics were evaluated. The variables were submitted to descriptive and frequencies analysis. Comparisons of categorical variables among groups were made with the Chi-square test. Significance level was set at 5% (p < 0.05). Results The mean age was 50 years (range 22 to 84 years). Most patients had stage cT3 or cT4 disease (74.6%) and clinically positive lymph node(s) (81.5%). Luminal “like” tumors comprised 45% of the patients and 27.9% were triple negative. Biopsy for suspected axillary lymph node was performed in 49.5% (32.8% of these were positive). Conservative surgery was performed in 23.1%. All patients received breast or chest wall irradiation; 91.5% supraclavicular fossa (SCF) and axillary levels 2 and 3 irradiation, 1.4% only SCF; 8.7% underwent additional
axillary level 1 irradiation and 8.8% also received internal mammary chain RT; boost was delivered in 21.4% of the patients. Conventional fractionation (25 x 200 cGy) was used in 96.6%. Indication of SCF and levels 2 and 3 axillary lymph nodes irradiation was significantly related to younger age (≤ 60 years)(p = 0.03), stage cT3 or cT4 (p = 0.027) and clinically compromised lymph nodes at the time of diagnosis (p = 0.0001). Internal mammary chain irradiation was also correlated to clinically positive lymph nodes (p = 0.01) and stage ypT3 or ypT4 (p = 0.028). Conclusion RT indications and targets were based on tumors characteristics pre-NCT. More advanced disease at the time of diagnosis and age were the main determinants to define RT to nodal targets independently of NCT response. EP-1167 Accelerated Partial Breast Irradiation: A single center analysis. K. Nugent1, D. Kelly2, J. McCaffrey3, M. Maher4 1 St Lukes Radiation Network, Radiation Oncology, Dublin, Ireland 2 Cork University Hospital, Medical Oncology, Cork, Ireland 3 Mater Misericordiae University Hospital, Medical Oncology, Dublin 6, Ireland 4 Mater Misericordiae University Hospital, Radiation Oncology, Dublin 6, Ireland Purpose or Objective Our objective was to analyse the use of adjuvant accelerated partial breast radiation (APBI) at our center over a ten year period. We calculated the local recurrence rates, median follow up and overall survival in breast cancer patients who received APBI from 2006 to 2016 . In this retrospective cohort, we obtained the average tumour size, histology grade, hormone status and lymphovascular invasion (LVI) presence in order to review the breast cancer characteristics of the patients we selected to treat with this modality. Material and Methods We conducted a single institution retrospective review of all adjuvant breast cancer patients who received APBI from between January 2006 to September 2016 . Patients were identified from a prospectively-maintained dataset of all patients commencing ABPI. A retrospective chart review was conducted as to determine long term follow up outcomes. The following patient details were recorded: median follow up time, demographics, histology, node status, surgery type, adjuvant treatment and local recurrence. Primary outcome was loco-regional recurrence noting if recurrences occurred within the treated breast quadrant. Results During this period a total of 106 procedures were carried out. The average mean age at time of treatment was 68.2 years. The mean tumour size was 14.65mm, all were estrogen receptor positive and node negative. LVI was present in 8% of the patient cohort. Median follow up was 65 months. The local recurrence rate within the treated breast quadrant was 1.8% (95 CI 0.42-2.44) while the local recurrence rate within the ipsilateral breast was 2.8% (95 CI 1.2-3.3). Overall survival was 97%. Conclusion Our findings suggest that APBI is a reasonable adjuavant option for selected low risk breast cancer patients. EP-1168 male breast cancer; a review of patients treated from 2004 - 2013 (10yrs) P. Scott1, V. Vanderpuye1, J. Yarney1, N. Aryeetey1, H. Ayettey1, M. Dadzie1, Z. Meles1 1 Korlebu Teaching Hospital, National Centre for radiotherapy and Nuclear Medicine, ACCRA, Ghana