ESTRO 2023 - Abstract Book

S1020

Digital Posters

ESTRO 2023

Results With a median follow-up of 18 months (range7-31), all patients are alive without evidence of local, regional or distant relapse. Acute tolerance: 182p (48%) developed skin toxicity grade 1 and 15p (4%) grade 2; breast edema G1 in 9p (2%), G2 in 2p (0.5%). No other acute toxicities were observed. Late complications: G1 breast edema in 6p (2%); G1 hyperpigmentation in 20p (5%); G1 late fibroses in 10p (3%) and G2 in 2p (0.5%) We found a statistically significant correlation between the mPTVbreast and presence of skin toxicity (p =0.028) as well as a significant correlation between late hyperpigmentation with the mPTVboost (p = 0.007) and the ratio PTV boost volume/PTV breast volume (p = 0.042) (Table 2).

Conclusion UHF-WBI with SIB in 5 fractions along one-week is feasible and well tolerated. Higher boost volumes are associated with a slightly worse long-term cosmetic outcome. However, longer follow-up is necessary to confirm these results.

PO-1276 Quality of life analysis of adjuvant external beam APBI in prospective randomized trial.

P. Burkon 1,2 , I. Selingerova 3,4 , M. Slavik 1,2 , T. Kazda 1,2 , M. Vrzal 1 , P. Slampa 1,2 , K. Polachova 1

1 Masaryk Memorial Cancer Institute, Department of Radiation Oncology, Brno, Czech Republic; 2 Faculty of Medicine, Masaryk University, Department of Radiation Oncology, Brno, Czech Republic; 3 Masaryk Memorial Cancer Institute, Research Centre for Applied Molecular Oncology, Brno, Czech Republic; 4 Faculty of Medicine, Masaryk University, Department of Pharmacology, Brno, Czech Republic Purpose or Objective Accelerated partial breast irradiation (APBI) represents a valid option for adjuvant therapy of selected early breast cancer (BC). Mentioned single-institution prospective randomized study compared the effectiveness and side effects of the external APBI using the stereotactic approach with the more commonly used accelerated WBI. Evaluation of health-related quality of life (HRQoL) was likewise included. After the 1-year follow-up, the results of the HRQoL analysis are presented. Materials and Methods Eligible patients were women over 50 years with early BC after breast-conserving surgery. APBI arm consisted of 30 Gy in 5 fractions and WBI of 40,05 Gy in 15 fractions plus 10 Gy in 5 fractions boost on tumour bed. A total of 84 patients were enrolled in the study (42 in APBI and 42 in WBI arm). For HRQoL assessment, patients were asked to complete the official Czech translation of EORTC QoL questionnaires, QLQ-C30, and the QLQ-BR45 questionnaires before the radiation (baseline), at the end of radiation (M0) and 1 (M1), 3 (M3), 6 (M6), and 12 (M12) months after radiation. Results No significant difference was observed between the two arms at HRQoL scores at baseline. Global health status and most scores of the functional and symptom scales of QLQ-C30 and the QLQ-BR45 did not show significant differences between