ESTRO 36 Abstract Book

S617 ESTRO 36 2017 _______________________________________________________________________________________________

Hypofractionated radiotherapy for post-operative breast cancer has consolidated as the standard treatment for breast cancer due to similar results compared with mastectomy in terms of local relapse, disease recurrence and survival rates. On clinical trials, Multiples fractionated schemes have been tested in the past years, demonstrating that hypofractionated whole-breast irradiation was not inferior to standard radiation treatment in women who had undergone breast- conserving surgery for invasive breast cancer with clear surgical margins and negative axillary nodes. The purpose of this study was to compare the economic outcomes in our institution resulting from an hypofractionated treatment in selected patients. Material and Methods A retrospective review from January 1º 2010 to December 31º 2015 of hypofractionated whole-breast irradiation was performed. Inclusion criteria was: Early breast cancer (I, II) Breast-conserving surgery, Age >18 years and absence of previous RT treatment at the same area. Pregnancy, breastfeeding and axillary nodes involvement were excluded. 3D conformal radiotherapy was delivered with 6-15 MV photons: 40 Gy in 15 fractions, 5 fractions per week. Additionally, boost doses to the tumor bed in patients <50 years, close margins of IDC or positive margins on DCIS with an equivalent dose in 2Gy fractions (EQD2) of 10-20 Gy. The estimated cost by treatment was obtained multiplying the number of sessions received by the stipulated cost of each session according to the law in force. Additionally we calculated an estimated cost of the treatment as if it has been performed with conventionally fractionated schedule, comparing the total amount between treatments. Results 361 patients who fitted the inclusion criteria were treated in our institution using hypofractionated schemes. The cost by session was estimated in 285,53€ according with the law in force provided by the Economic department of our institution. 75,6% (n273) of patients received 15 fractions with an estimated cost by treatment of 1.169.245,35€ and the remain 24,4% of patients (n88) received 18 fractions with an estimated cost of 452.279,52€. Comparing a standard irradiation in 25 fractions with hypofractionated irradiation in 15 fractions, a total saving estimated on 779.496,9€ was obtained. Likewise in patients who underwent boost doses to the tumor bed receiving 18 fractions, a total saving of 301.519,68€ was calculated compared to a conventional treatment of 30 fractions. Conclusion The increasing demand of treatments in health care institutions makes necessary the implementation of cost- efficacy strategies, in attendance of each patients needs without letting a side the importance of optimization of health resources. Hypofractionated schedules reduces the total time of treatments which translates in a reduction of sanitary personnel costs, time machine, waiting lists, transportation and patient discomfort among others. EP-1144 Old age impact on radiotherapy omission in breast cancer patients S. Cima 1 , B. Muoio 1 , P. Fanti 1 , A. Richetti 1 , C. Azinwi 1 , F. Martucci 1 , K. Yordanov 1 , G. Pesce 1 , M. Valli 1 1 Istituto Oncologico della Svizzera Italiana, Radiation Oncology, Bellinzona, Switzerland Purpose or Objective Increasing life expectancy and overall aging in the western countries will improve the impact of breast cancer treatment in old women. The aim of this study was to analyse the impact of age on post-operative radiotherapy (RT) omission in breast cancer patients, older than 69 years. Material and Methods

We analysed retrospectively 384 women, treated from January 2007 to June 2015, dividing them into three subgroups: 70 to 79 years, 80 to 89 years and 90 years and older. Results A total of 280 patients (72.9%) were treated with conservative surgery. The adjuvant RT was given to 135 patients (71.4%) aged 70-79 years, 27 patients (34.2%) aged 80-89 years and 3 patients (25%) older than 90 years. RT was omitted in 115 (41.1%) cases. A significant correlation was observed between age and RT omission, comparing younger subgroup to the others (p<0.001 and p=0.002), with a smaller number of older patients treated with RT. The 2 and 5 year DFS of patients treated with conservative surgery was 94.5% and 82.7% without significant difference between age subgroups (p=0.36). No significant difference in 2 and 5 years DFS was detected (p=0.12) between patients treated with adjuvant RT and conservative surgery alone (p 0.12). The 5 year OS was 81% in patients aged 70-79 years; 71% in patients aged 80-89 years and 65% in patients older than 90 years, with a significant difference (p=0.009). The 5 year OS in patients treated with adjuvant RT was 79% while it was 75 % in patients treated with conservative surgery alone, without significant difference (p=0.11). Mastectomy was performed in 124 patients: 17 patients (13.7%) received RT while 107 (86.3%) no further RT, with omission in 22 patients (17.7%).The adjuvant RT was given to 13 patients (16.7%) aged between 70-79 years, 4 patients (10.3%) aged between 80 and 89 years, while no patients older than 90 years was treated with post-mastectomy RT. No statistically significant difference in term of RT omission was observed between age subgroups, comparing younger subgroup to the others (p=0.40 and p=0.60). The 2 and 5 year DFS of patients treated with mastectomy was 90% and 81.7% without significant difference between age subgroups (p=0.51). The 2 year DFS in patients treated with adjuvant RT was 91% and 89% in patients treated with mastectomy alone. The 5 year DFS in patients treated with adjuvant RT was 86% and 65% in patients treated with mastectomy alone. No significant difference was detected (p=0.26). The 5 year OS was 70% in patients aged 70-79 years; 55% in patients aged 80-89 years and 14% in patients older than 90 years, with a significant difference (p<0.001). The 5 year OS was 64% and 52% in patients treated with or without adjuvant RT respectively, without significant difference (p=0.12). Conclusion An higher percentage of patients aged between 70-79 years received RT after conservative surgery if compared with the older subgroups. No difference was detected in RT omission after mastectomy. EP-1145 Troponin I for the detection of cardiac toxicity in adjuvant breast cancer radiotherapy K. Boudaoud 1 , H. Allioueche 2 , O. Haderbeche 2 , K. Sifi 3 , S. Taleb 4 , C. Kourteli 5 , K. Benmebarek 3 , M. Setta 6 , S. Serradj 6 , T. Filali 7 , A. Djemaa 4 , N. Abadi 3 1 Scientific research laboratory of molecular biology and genetics- Faculty of Medicine- UC3, Radiation oncology, Constantine, Algeria 2 CHUC, Radiation oncology, Constantine, Algeria 3 Scientific research laboratory of molecular biology and genetics- Faculty of Medicine- UC3, Laboratory of biochemistry, Constantine, Algeria 4 Faculty of medicine- UC3, Radiation oncology, Constantine, Algeria 5 University Constantine 1, Radiation oncology, Constantine, Algeria 6 Faculty of Natural and Life Sciences- UC1, Department of animal biology, Constantine, Algeria 7 Scientific research laboratory of molecular biology and genetics- Faculty of Medicine- UC3, Medical oncology, Constantine, Algeria