ESTRO 38 Abstract book

S707 ESTRO 38

In the adjuvant treatment of early-stage breast cancer the majority of departments (54.8%) used 3D - conformal tangential fields with a simultaneous integrated boost. 32.3% of the departments used intensity modulated radiation therapy (IMRT) with step-and-shoot, 29.0% with Rotation RT and 17.7% with sliding window ( Figure ). For internal mammary radiation the majority of participants (74.4%) used image guided radiation therapy (IGRT) with IMRT or volumetric modulated arc therapy (VMAT). When asked in which case participants would perform an irradiation of neck, supraclavicular and infraclavicular lymph nodes 67.2% indicated a case with 1-3 affected lymph nodes, with 100% treating a patient with >3 affected lymph nodes. Several questions focused on the participants’ standard treatment plans for various clinical situations.

MLD) as well as V20Gy for both organs were collected from treatment plans. Patients were classified according to RT technique used (3DCRT, IMRT or VMAT) and target volumes treated. Group comparisons were performed to analyze heart and lung doses for different techniques and for RT with and without irradiation of regional lymph nodes (LN). The relationship between patient characteristics (body mass index (BMI), heart and total lung volume) and radiation exposure of the heart and lung was assessed using correlation analyses. Results A total of 344 female patients treated with adjuvant radiotherapy for left-sided breast cancer were eligible for analysis. Patients received a median dose of 50 Gy to the breast or chest wall +/- regional LN. Two-third (n=227) were treated with 3DCRT, whereas one third (n=117) received IMRT/VMAT. Regional LN irradiation was performed in 32% of patients and more often involved usage of IMRT/VMAT (55.8% of treatments vs. 23.6% for cases without LN irradiation). Overall, IMRT/VMAT showed a higher MHD (4.8Gy vs 3.5Gy; p<0.01), left MLD (12.5Gy vs 8.6Gy; p<0.01) and V20Gy of the left lung (25% vs 16.9%, p<0.01) compared to 3DCRT. In a subgroup analysis of patients without LN irradiation (n=233), a difference remained for left MLD (IMRT/VMAT vs. 3DCRT 9.0Gy vs 7.2Gy; p<0.01) and V20Gy of the left lung (18.0% vs 13.6%; p<0.01). Inclusion of regional LN increased MHD (5.2Gy vs 3.4Gy; p<0.01) and left MLD (14.8Gy vs 7.6Gy; p<0.01) as well as V20Gy of the heart (5.3% vs 3.4%; p<0.01) and left lung (30.2% vs 14.6%; p<0.01) compared to treatment without regional LN. In particular, RT involving the internal mammary LN further increased heart and lung doses compared to RT involving only supraclavicular +/- axillary LN (p<0.01 for all values; MHD 8.3Gy vs. 4.6Gy). Assessment of patient characteristics revealed a weak negative association between total lung volume and both MHD (r=-0.38; p<0.01) and heart V20Gy (r=-0.36; p<0.01). In addition, a weak positive correlation of BMI and MHD (r=0.25; p<0.01) was observed. Conclusion While IMRT/VMAT has been shown to improve dose homogeneity and conformity in RT for breast cancer, this has to be weighed against an increase in radiation exposure of the lung and potentially the heart. Similarly, the impact of regional LN irradiation on heart and lung dose needs to be considered in clinical decision making. These observations may help tailor personalized RT for patients with left-sided breast cancer. EP-1291 Radiation Treatment Standards and Techniques in Breast Cancer in German speaking countries M. Mayinger 1 , C. Straube 2 , D. Habermehl 2 , S.E. Combs 2 1 Universitätsspital Zürich, Radiation Oncology, Zürich, Switzerland ; 2 Technical University of Munich, Radiation Oncology, Munich, Germany Purpose or Objective The large amount of prospective trials in early breast cancer has caused a vide variety in possible treatment techniques in early-stage breast cancer. Therefore the aim of this study is to assess radiation treatment standards and techniques in early-stage breast cancer in German speaking countries. Material and Methods Between July 2017 and August 2017, an email-based survey was sent to all 1408 physicians that are members of the German society of radiation oncology (DEGRO). The survey was completed by 180 physicians including 10 private practice owners and 52 heads of departments of community-hospital or university-hospital based radiation oncology services. The majority (82.1%) of the participants had >15 years of experience in radiation therapy (RT). Results

Conclusion Our patterns of care survey showed that the majority of departments and radiation oncologists in German speaking countries align with the new S3 and AGO guidelines. For the adjuvant treatment of early-stage breast cancer 3D - conformal tangential fields with a simultaneous integrated boost is the preferred treatment technique. The use of IMRT is still limited to a specific patient cohort, although the majority of participants selected IGRT – IMRT / VMAT for irradiating the internal mammary lymphatic chain. EP-1292 Zinc-L-Carnosine prevents dysphagia in breast cancer patients treated with adjuvant radiotherapy S. Saldi 1 , E. Perrucci 1 , V. Lancellotta 2 , I. Palumbo 2 , L. Falcinelli 1 , C. Mariucci 2 , S. Chierchini 2 , V. Bini 3 , C. Aristei 2 1 Santa Maria della Misericordia Hospital, Radiation Oncology, Perugia, Italy ; 2 University of Perugia, Radiation Oncology, Perugia, Italy ; 3 University of Perugia, Internal Medicine Section of Internal Medicine and Metabolic and Endocrine Disease, Perugia, Italy Purpose or Objective Irradiation of level III and IV draining nodes in breast cancer patients is often associated with dysphagia, requiring treatment with FANS and/or steroids. The present randomized phase III trial determined whether Zinc-L-Carnosine (ZLC, Hepilor®), prevents or delays the onset of dysphagia in these patients. Material and Methods December 2015-October 2017: 40 breast cancer patients undergoing radiation therapy (RT) to the breast or chest wall and level III and IV lymph-nodes were randomized to receive ZLC or placebo. All underwent RT with Tomotherapy at a total dose of 50 Gy in 25 fractions. 11/40 (27,5%) women who had received conservative surgery were given a 10 Gy boost to the tumor bed, using a simultaneous instantaneous boost technique. The primary end-point was no dysphagia, as evaluated by the CTCAE v 4.0 and EAT-10 questionnaire. The trial was approved by the Regional Ethics Committee and all