ESTRO 36 Abstract Book

S635 ESTRO 36 _______________________________________________________________________________________________

Purpose or Objective Male breast carcinoma (MBC) is rare, and the incidence varies worldwide. It accounts for about 1% of all breast cancers. Due to the rarity of this disease, there is a lack of prospective clinical trials to define its optimum treatment. Current data consists mostly of small retrospective studies, hence treatment generally follows the principles established for that of female breast cancer. The purpose of this study was to review and analyse breast cancer in men managed from 2004 to 2013. Material and Methods Men with histologically confirmed breast cancer from 2004–2013 were studied. Information regarding patient demographics, presenting symptoms, tumor characteristics, treatment and outcomes were analysed. Results Over the 10 year period, 41 patients were studied, making 1.6% of all breast cancer cases managed. Median age at diagnosis was 66 years, ranging 36-89. Majority, 87.8%, self-detected a lump in the breast. The median time from onset of symptoms to diagnosis was 12 months, ranging 3–48. The commonest histology was invasive ductal carcinoma ,70.7%. Stage III disease represented 47.58%, while stage I, II and IV disease made up 7.32%, 19.61% and 25.49% respectively Hormone receptor (HR) status was unknown in 63.4%, 14.6% were estrogen receptor (ER) only positive, 7.3% were progesterone receptor (PR) only positive, 4.9% were ER and PR positive, and 9.8% were ER and PR negative. Of those who had their HR status checked, 73.2% were HR positive. Modified radical mastectomy was the most common surgical procedure, 46.3%, mastectomy only in 14.6% and breast conservation in 7.3%. 46.3% of patients received adjuvant radiotherapy. 48.8% did not receive adjuvant radiotherapy because they were metastatic, defaulted or presented late after the surgery. 40.3% received chemotherapy in adjuvant, neoadjuvant or metastatic setting. Hormone receptor positive patients had Tamoxifen. Median follow up duration was 7 months, ranging 0-64. Median survival was 13 months and 5 year overall survival of 2%. Conclusion MBC makes up 1.6% of all breast cancer presenting to our centre, consistent with worldwide findings of about 1%. Majority presented with locally advanced or metastatic disease. Outcomes are poor and could be due to late presentation. Screening programs may translate into better outcomes. MBC is frequently hormone receptor positive and may be more sensitive to hormonal therapy, hence receptor status testing is recommended. Low survival and poor follow up made disease free survival difficult to determine. EP-1169 Preoperative CT scan in tumor bed delineation after breast conserving surgery and oncoplasty T. Saxena 1 , V. Goel 1 , G. Kadyaprath 2 , D. Arora 3 , A.K. Verma 1 , P. Agarwal 1 , P. Kumar 1 , J. Jain 1 , R. Shukla 1 , P. Kumar 3 , A. Masanta 3 , T.R. Singh 4 , R. Kaur 4 , A.K. Anand 1 1 Max Hospital- Delhi- India, Radiation Oncology, Delhi, India 2 Max Hospital- Delhi- India, Surgical Oncology, Delhi, India 3 Max Hospital- Delhi- India, Medical Physics, Delhi, India 4 Max Hospital- Delhi- India, Radiation Therapy Technologist, Delhi, India

Purpose or Objective Background: Tumor bed (TB) boost, in addition to whole breast radiation therapy (WBRT) improves local control rates as compared to WBRT alone after breast conserving surgery (BCS). There are several pitfalls in localizing TB accurately. Surgical clips are generally placed over pectoralis muscle, even if the tumor is superficial and hence not truly representative and there is always a concern of clip migration. Mammogram and MR mammogram are not quite useful as they are done in a non-anatomic position. Problem of accurate TB identification is further compounded in patients with oncoplastic reconstruction. In oncoplastic surgeries (OPS), scar is often not representative of tumor location. Seroma cavity is generally obliterated by tissue repositioning. Hence, TB delineation is sum total of information from surgical notes, surgical clips, postoperative changes on radiation therapy (RT) planning scans, histopathology report and some calculated guess work. Objective: To determine utility of preoperative CT scan in TB delineation after BCS. Material and Methods This pilot study was conducted in Department of Radiation Oncology, Max Hospital, Delhi, India, on 21 breast cancer patients in whom prior to BCS, preoperative CT scan was done in treatment position on a flat couch, in CT simulator. A radio opaque fiducial was also placed at the centre of palpable lump. After BCS & chemotherapy (if any), RT planning CT scan was taken with similar set up as pre-operative CT scan. Both the scans were co-registered using non-deformable registration on Eclipse Version 10.0. TB was contoured on RT planning CT using surgical clips (TB1) and also on preoperative CT scan (TB2). Tumor bed on all RT planning scans were scored for Cavity Visualization Score (CVS). Relative shift in position of TB on both the scans was compared in all three [lateral (RL), cranio caudal (CC) and Antero-posterior (AP)] directions. Results In our patients, median age was 59 years (Range 42-71). Median of maximum tumor size was 2.5 cm (Range 1.0- 5.0). All patients underwent BCS with oncolplastic reconstruction. Median time between preoperative and RT planning scan was 4.6 months. CVS 1 and 5 was observed in 6 patients each and rest patients were having CVS 2, 3 or 4. Mean preoperative, postoperative and combined tumor volume were 10.9cc, 10.9cc and 23.4cc respectively. On evaluating relative positions of tumor bed on pre-operative vs RT planning scan, mean (± SD) RL shift was 2.8 cm (± 1.8), which was larger than for the other directions (CC shift 1.2 cm, SD ± 0.9; AP shift 1.6 cm, SD ± 1.1). When relative shifts of TB were co-related with tumor location, RL & CC shifts were more in outer quadrant tumors (p=0.0005 & 0.016 respectively), while in AP direction, p value (0.26) was not statistically Preoperative CT scan in treatment position is an additional useful tool in calculated guess work of TB delineation and helps in improving the accuracy of target volume delineation for TB boost. EP-1170 Hypofractionated radiotherapy for ductal carcinoma in situ using VMAT: acute toxicity and cosmesis F. De Rose 1 , A. Fogliata 1 , D. Franceschini 1 , C. Iftode 1 , A.M. Ascolese 1 , T. Comito 1 , L. Di Brina 1 , A. Tozzi 1 , C. Franzese 1 , E. Clerici 1 , G.R. D'Agostino 1 , P. Navarria 1 , F. Lobefalo 1 , M. Scorsetti 1 1 Istituto Clinico Humanitas, Radiotherapy and Radiosurgery, Rozzano Milan, Italy significant. Conclusion