ESTRO 2024 - Abstract Book

S2080

Clinical - Sarcoma, skin cancer, melanoma

ESTRO 2024

NMSC research and education is very poorly represented at the annual ESTRO congress, representing only 0.5% of abstracts presented. This contrasts to the high and rapidly increasing number of patients with NMSC seen in clinical practice, including in skin radiotherapy/brachytherapy and immunotherapy. A focus on NMSC teaching and educational course is warranted given the further expected increase in patient numbers over time and burden on national health systems across the world.

Keywords: abstracts, non melanoma skin cancer, research

550

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Does radiation therapy play a role in osteoblastoma? The 25-year single institutional experience

Bartłomiej Szostakowski 1 , Tadeusz Morysiński 1 , Piotr Rutkowski 1 , Mateusz Jacek Spałek 1,2

1 Maria Sklodowska-Curie National Research Institute of Oncology, Department of Soft Tissue/Bone Sarcoma and Melanoma, Warsaw, Poland. 2 Maria Sklodowska-Curie National Research Institute of Oncology, Department of Radiotherapy I, Warsaw, Poland

Purpose/Objective:

Osteoblastoma is a very rare, locally aggressive benign bone tumor. Radiotherapy (RT) is one of the treatment options for unresectable or recurrent osteoblastoma. However, the outcomes of RT are rarely reported due to the rarity of the disease and lack of guidelines.

The objective of the study was the assessment of indications and efficacy of RT for patients with osteoblastoma who were treated in our tertiary center.

Material/Methods:

The study group was a retrospective cohort of consecutive patients with centrally reviewed and confirmed osteoblastoma treated in our institute that received definitive RT in the years 1998-2023. The following parameters were analyzed: indication for RT, irradiated site, total dose (TD), dose per fraction (DF), early and late tolerance, and survival.

Results:

A total of n=13 patients (age 17-68 years) who underwent definitive RT for osteoblastoma were identified. All but three patients had osteoblastoma of the spine. All but one patient received definitive RT for unresectable disease, mostly localized to the thoracic and lumbar spine. All patients underwent conventionally fractionated RT (DF 1.8-2.0 Gy) to TD 40-70.2 Gy. The median follow-up was 7 years. Only mild acute toxicity was observed. No late toxicity was reported. Local progression was observed in four patients, all of whom died.