Stereotactic body radiation therapy (SBRT) for patients with oligometastatic/oligoprogressive adrenal metastases. Outcomes and toxicities profile in a monoinstitutional study

Aims: To evaluate survival outcomes and toxicology profiles in oligometastatic/oligoprogressive patients treated with SBRT for adrenal metastases. Methods: We retrospectively analyzed 25 metastatic adrenal lesions in 24 oligometastatic/oligoprogressive patients undergoing ablative Stereotactic Body Radiation Therapy (SBRT) between February 2010 and November 2019 in our department. The primary endpoint was overall survival (OS). Secondary endpoints were local overall response rate (ORR), acute and late toxicities. Results: The most common primary tumor was non-small cell lung cancer (54%). Twenty-one patients received chemo or immuno-therapy. The median planning target volume (PTV) was 41.7 cm3. Median SBRT dose was 36 Gy. Median dose per fraction was 15 Gy. Median survival was 35-months with OS outcomes ranging from 6-months (100%), 1-year (87.5%) and 2-years (66.7%). ORR based on RECIST criteria was 66.5%. 12 patients experienced acute toxicities, mostly grade 1–2 (8 patients, 32%). Conclusions: SBRT for oligometastatic/oligoprogressive patients with adrenal metastases showed acceptable survival outcomes and a safe toxicity profile.