ESTRO 2025 - Abstract Book

S905

Clinical - Haematology

ESTRO 2025

Radiation Oncology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain

Purpose/Objective: Cutaneous lymphomas are a heterogeneous group of non-Hodgkin's lymphomas, mostly T-cell type. Low dose radiotherapy has been proved as an effective treatment for local control, both in monotherapy and as part of a multidisciplinary management. The aim of our study is to analyse the local control and patterns of relapse in patients with cutaneous lymphomas treated with radiotherapy in our institution. Material/Methods: A retrospective study has been conducted in patients treated with superficial radiotherapy for cutaneous lymphoma between 2014 and 2023. Treatment characteristics, dosimetric parameters and clinical data were analysed. Results: A total of 29 patients with 37 lesions were treated with radiotherapy in a period of 10 years. Median age was 77 (range 35 - 96 years). 55.2% of patients received other treatments before radiotherapy, including corticosteroid, phototherapy, chemotherapy and surgery. Regarding radiotherapy treatment, the median dose was 15 Gy in 5 fractions (range 8-30 Gy in 1-15 fractions). All of the schedules included were daily sessions. 27 out of 29 patients were treated with 50kV RX for a 0.5-2cm of depth, The median follow-up was 4.3 years (range 1.4 – 9.9). 1 year local control was 74%. Complete response was observed in 69% of patients at last follow up, while 44.8% of patients showed distant progression and 27.6% local progression. All cases of local progression were B-cell lymphomas. 6 of the 8 patients that presented local progression were re-irradiated. In a multivariate analysis with Cox regression method, no significant differences were found between local recurrence and sex (p=0.11), histology (p=0.96), treated site (p=0.76), diameter of lesion (p=0.98) or dose (p=0.96). Mean overall survival was 7.7 years. 3 of the 8 deaths were related to progression of the lymphoma. Acute toxicity was observed in 27.5% of patients (17.2% G1-2 epithelitis and 6.9% alopecia). Only one patient had toxicity G3 (epithelitis). Late toxicity with radiodermatitis was detected in 10.3% of cases. whereas the other 2 patients with 80kV for a 4cm of depth. The patients and treatment characteristics are shown in Table 1.