Stereotactic Body Radiotherapy in Latin America: Real-World Evidence of Health Outcomes

Abstract

Stereotactic body radiotherapy (SBRT) is an ultrafractionated radiotherapy modality approach to treat oligometastatic disease. Randomized trials have shown significant benefit on overall survival and disease-free survival. In the last decade multiple studies have support efficacy and safety of this new technique. However, data from Latin America and Mexico are limited. In Mexico only 5% of facilities develop SBRT in daily practice. Therefore, the aim of this study was to investigate the real-world outcomes of applying SBRT for oligometastatic in a Mexico institution. This study investigated a consecutive cohort of patients treated with SBRT. at Centro medico ABC in Mexico City (Mexico). Oligometastatic disease have been treated using different schedules from 30-60Gy/5-8 fractions (fx.). All p. were treated on LINAC (Novalis Tx), IGRT with ConeBeam CT and Exactrack. The study primary outcome was local control rates per lesion. Secondary outcomes included progression-free survival (PFS), overall survival (OS), and toxicity profile (CTCAE 3.0). Between February 2015 and October 2022, 51 patients (p.) have been treated with SBRT in 71 lesions. The median follow-up was 17 months (2-60). Mean age was 59 years old (8-99), 1:1 sex ratio. primary tumor 21p. GI tumors, 10p. GU tumors, 6 p. sarcomas, 6 p. lung cancer, 6p., 5p. breast ca. and others 7p. locations treated were 21p. lung lesions, 16p. bone, 10p. liver, 6p. nodes and others (9p.). The average number of fractions and total dose prescribed was 5 (1-8)/38 Gy (18-60 Gy). Local response rates were complete response 24p. (33%), partial response 16p. (22%), stable 8p. (11%), progression 13p. (18%). Overall survival rate was 55 months. Acute toxicity grade 3 was observed in 2p. gastric ulcer surgically treated, 1p. liver disfunction (prior Child B). Late toxicity was observed in 2 p. painful lung fibrosis surgically resected. Our results indicate that SBRT is effective (high local control and acceptable toxicity) for treating oligometastatic in a real-world scenario in Mexico.