ESTRO 2024 - Abstract Book

S2536

Clinical - Urology

ESTRO 2024

During the period, 261 lesions were treated, of which 105 were excluded, thus resulting in 156 lesions in 118 patients to be analyzed. 71 lesions were vertebral metastases, and 27 lesions were treated with EQD2>44 Gy. After a median FU of 24 months, local control was 73% and 27 local recurrences observed. In the MVA, the type of bone metastases (spine vs non-spine [HR=2.96, p=0.007]) and EQD2 (dose >44 Gy [HR=0.26, p=0.02]) both statistically significantly affected local control. Median survival was 38.5 months (2-year OS 56%). In the MVA, reduced general condition (ECOG>1 [HR=2.09, p=0.004]), number of metastases (n>4 metastases [HR=2.96, p<0.001]) and type of metastases treated (spine vs non-spine [HR=2.36, p<0.001]) statistically significantly influenced overall survival.

Conclusion:

In patients with bone metastases from RCC, a higher EQD2, amongst other factors, leads to improved local control and overall control. The extent, to which improved local control has an influence on patient-relevant endpoints, should be evaluated in prospective studies.

Keywords: Renal cell cancer, bone metastases, dose response

2475

Digital Poster

The impact of lifestyle and health on second primary cancer risks after EBRT for prostate cancer

Wilma D Heemsbergen 1 , Luca Incrocci 1 , Katja KH Aben 2,3 , Kim C de Vries 1 , Mischa Hoogeman 1 , Maartje J Hooning 4 , Marie C Jahreiss 1 1 Erasmus MC Cancer Institute, Radiotherapy, Rotterdam, Netherlands. 2 Netherlands Comprehensive Cancer Organization, Research Dept, Utrecht, Netherlands. 3 Radboud UMC, Dept for Health Evidence, Nijmegen, Netherlands. 4 Erasmus MC Cancer Institute, Medicall Oncology, Rotterdam, Netherlands

Purpose/Objective:

In evaluating second primary cancers (SPC) following External Beam Radiotherapy (EBRT) lifestyle factors like smoking and comorbidities are frequently not considered due to data limitations in sources like national cancer registries. This is regarded as a potential bias factor because patients undergoing EBRT represent a subset of non operable cases with underlying health issues (1). Moreover, it has been suggested that the increased SPC risk observed in EBRT-treated patients cannot be solely attributed to radiation exposure. We investigated the association between smoking, comorbidities and SPC risks in the pelvic and non-pelvic anatomical subsites within a cohort treated with EBRT for localized prostate cancer (PCa).

Material/Methods: