Emerging radiotherapy technology in a developing country: A single Brazilian institution assessment of stereotactic body radiotherapy application.

Objective:: To provide a quantitative profile of the indications and use of stereotactic body radiotherapy (SBRT) in a developing country oncology-based institution. In addition, to describe the patients' and treatment characteristics, and to provide a temporal analysis.

Method:: SBRT patients treated from 2007 to 2015 were retrospectively evaluated by two independently investigators. Data were stratified and compared in two periods: first experience (FE) (May 2007 to April 2011), and following experience (FollowE) (May 2011 to April 2015). The following parameters were compared between the groups: total number of treated patients and lesions, treatment site, additional image fusion used, formal protocol adoption, and SBRT planning technique.

Results:: One hundred and seventy-six (176) patients with 191 lesions were treated: 34 (18%) lesions in the FE and 157 (82%) lesions in FollowE. The majority of lesions were metastases (60.3%), and lung (60.2%) was the most common treatment site, followed by spine (31%), and others (8.8%). An average of 1.4 (±0.6) additional imaging exams for delineation was performed. Conformal 3D radiotherapy planning technique was used in 64.4%, and intensity modulated radiotherapy (IMRT) or volumetric-modulated arc therapy (VMAT) in the remaining 35.6% (p=0.0001). Higher rates of curative treatments were observed in FE, as well as more lung lesions, patients ≥ 70 years, 3D conformal, number of additional images and ECOG 0, and all presented p<0.05. The global rate of protocol statement was 79%, lung treatment being the most stated.

Conclusion:: SBRT application is rapidly increasing in our setting. Treatment sites and planning techniques are becoming more diversified and complex.