Abstract Book

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ESTRO 37

diagnosis of breast cancer and the associated treatments may also contribute for worsening pre-existing sleep problems. In this study, we aimed to assess the relation between radiation therapy and sleep disturbances in patients with breast cancer. Material and Methods Thirty women with breast cancer about to receive RT following breast conserving surgery were evaluated for sleep quality (SQ) using Pittsburgh Sleep Quality Index (PSQI), depression using Beck Depression Inventory (BDI), hopelesness using Beck Hopelessness Scale (BHS) and QoL using cancer-specific (EORTC QLQ-C30 and EORTC QLQ- B23) questionnaires. Questionnaires were administered on the first day of RT. Global health status/QoL (QL2) scale for the EORTC QLQ-C30 questionnaire was scored from 0 to 100, the higher scores representing better QoL. Systemic therapy side effects scale (BRST) and future perspective scale (BRFU) for the EORTC QLQ-B23 questionnarie were scored from 0 to 100, the lower scores representing better QoL. Results PSQI scores ranged from 2 to 17 (median, 7). Scores over 8 were classified as poor sleepers. BDI scores ranged from 1 to 37 (median, 13). Scores over 10 were classified as having depression. BHS scores ranged from 0 to 12 (median, 3). Scores less than 4 were classified as having no hopelessness at all. Accordingly, there were 9 patients who were poor sleepers, 17 who had mild to severe depression and 13 who were hopeless. There was a strong, positive correlation between PSQI scores and BDI scores (p=0,004). There was a positive correlation between PSQI scores and BHS scores (p=0,09). EORTC QoL-C30 (QL2) scores ranged from 33 to 100 (mean, 64) EORTC QoL-BR23 (BRST) scores ranged from 0 to 90 (mean, 32) and EORTC QoL-BR23 (BRFU) scores ranged from 0 to 100 (mean, 40). There was a strong, positive correlation between PSQI scores and EORTC QoL-C30 (QL2) scores (p=0,02). There was a positive correlation between PSQI scores and EORTC Qol-BR23 (BRST and BRFU) scores (p=0,06 and p= 0.007). The mean EORTC QoLC30 (QL2) score for good sleepers was higher as compared to that for poor sleepers (69 versus 51, p=0.03) and the mean EORTCBR23 (BRST and BRFU) scores for good sleepers was lower as compared to those for poor sleepers (27 versus 42, p=0.20 and 32 vs 59, p=0.03). Conclusion Self-administered measurements such as PSQI, BDI, BHS and EORTCQ30 might be used as a simple means to collect data on multiple facets of SQ, the depression status and the level of hopelessness. In this study, poor sleep was prevalent among breast cancer patients, usually coupled with depression, hopelessness and poor QoL. Therefore, poor sleep deserves adequate medical attention in terms of supportive care. EP-1340 Assessment of risk/dosimetric factors of radiation induced toxicities in breast cancer radiotherapy M. Loos 1 , K.J. Borm 1 , M. Oechsner 1 , D. Paepke 1 , S.E. Combs 1 , M.N. Duma 1 1 Medical School- Technical University Munich- Munich- Germany, Department of Radiation Oncology- Klinikum Rechts der Isar- Technical University Munich- Munich- Germany, Munich, Germany Purpose or Objective 3DCRT is regarded as a standard therapy for breast cancer. Studies on IMRT postulate a better and more homogenous dose distribution and thus less side effects. The aim of our work was to examine risk/dosimetric factors of acute toxicities in a large cohort of patients treated with multiple field 3DCRT. Material and Methods The study comprises 276 patients with breast cancer. The median age was 54,5 (23-85 years). All patients received multiple filed, optimized, tangential 3DCRT. The median

prescribed dose was 50,4 (range 50-50,4) median boost 10 Gray (range 0-16). All patients received whole breast irradiation (WBI). 38 patients had no boost, 137 a sequential boost of 10 and 100 patients 16 Gy (1.8-2 Gy single dose) . Toxicities were evaluated by CTCAE v 4.03. Both, the skin dose as well as the breast tissue dose were evaluated. Using the dosis of the mammary gland the patients were categorized in groups with < 105 % of the prescribed dose (pd WBI), 105 %-107 % or > 107 % . Further 110% of the prescribed dose was analyzed as it is considered to be predictive for acute toxicities. In the group of 276 patients, there were 28 smokers, of whom 10 received a treatment with 50 Gy WBI+ 16 Gy boost. They were matched to a group of 90 non-smoking patients with same radiotherapy. Of all 276 patients 119 had chemotherapy. 26 of these 119 patients had a chemotherapy with Epirubicin, Paclitaxel and Cyclophosphamide and a radiotherapy of 50 Gy WBI +16Gy Boost. They were matched to 58 of the 276 patients who did not receive any chemotherapy, but the same radiotherapy-treatment. Results 3/276 patients(1,08%) had a >110%pdWBI; 33/276(11,95 %) >107%pdWBI; 209/276 (75,72%) 105%-107%pdWBI; 8/276 (2,89 %) < 105%pdWBI. Comparing the CTC-Scores of the different groups, there was no significant differnces between the 3 groups (p>0.05). 3(30%) of the smoking patients had a CTC °1; 7 (70%) a CTC °2 at the end of therapy. 41 (46,06%) of the non smoking patients had a CTC °1; 48 (53,93%) a CTC °2; 1(1.2%) a CTC °3. There was no significant difference between the patients with or without chemotherapy (p=0.8). 11 chemotherapy patients (42%) had a CTC °1 and 15 patients (57,69%) had a CTC °2. Of the 58 patients without chemotherapy 22 (37,93%) showed a CTC °1; 36 (61,01%) had a CTC °2. There was a statistical significant difference in the CTC- Score of the WBI with and without boost (p=0.008). There was no significant difference between the 10 Gy vs 16 Gy boost (p=0,78). Conclusion Modern multiple field tangential WBI 3D-CRT results in a homogenous dose distribution, with dosimetry similar to data published on randomized trials on IMRT. Thus the toxicities are low and within the reported with IMRT. Neither nicotine consumption nor chemotherapy stood in a significant relation with radiodermatitis in this large cohort. While there was a statistic significant difference between the boost vs no boost patients, there was no statistical difference between the of 10 Gy and 16 Gy group. EP-1341 Contralateral breast : A missing organ at risk in breast radiotherapy F. Nejla 1 , C. Ines 1 , M. Wafa 1 , F. Zied 1 , F. Leila 1 , K. Mouna 1 , S. Wicem 1 , D. Jamel 1 1 Hopital Habib Bourguiba, Radiation Oncology, Sfax, Tunisia Purpose or Objective The aim of this study was to determine the dose received by the contralateral breast (CB) during radiotherapy for breast cancer. Material and Methods Between January 2015 and September 2017, 100 newly diagnosed patients with non-metastatic breast cancer were treated with adjuvant radiotherapy in our department. The median age was 50.5 years (23-81 years). The majority of patients had a left breast cancer (68%). All patients received a 3D conformal radiotherapy. The prescribed dose was 66 Gy (2Gy per fraction) after conservative surgery (n=63) and 50 Gy (2Gy per fraction) after modified radical mastectomy (n=37). The contralateral breast was not considered as an organ at risk and we retrospectively contoured it to determine the received dose at its level. We then reported the