Radiosurgery and Stereotactic Radiotherapy for Brain Metastases According the New Prognostic Indexes: our Preliminary Experience

Abstract

Purpose: This work is a retrospective analysis of our experience in the treatment of patients with BMs using SRS or SRT with Cyberknife ® (CK) system (Accuray Inc., Sunnyvale, California, USA). The aim is to evaluate the local control of disease and overall survival according to modern prognostic indices. Material and methods: From November 2012 to March 2014, we treated 116 patients, (178 brain metastases), with CK system, an image-guided frameless robotic SRS/SRT. We stratified the patients according to the Diagnosis- Specific GPA (DS-GPA) and we treated patients with a single fraction (10-24 Gy) in 72%, with two fractions (18-21 Gy) in 3%, with three fractions (18-24 Gy) in 23%, with five fractions (20-25Gy) in 2%. The dose was prescribed to 80% isodose line. All patients were evaluated with clinical and radiological follow-up using MRI every 2 months. We calculated the local tumor control rate according with RECIST (Response Evaluation Criteria in Solid Tumors) criteria. Results: Percentage of complete remission, partial remission, stable disease, was: 38% in NSCLC (Non-smallcell lung carcinoma) (16% in classes with best score), 28% in Melanoma (all in classes with best score), 52% in breast (43% in classes with best score). We noted a similar result for partial remission and stable disease, particularly in Melanoma and Breast cancer, who have a higher percentage of PR (partial response) and SD (stable disease) of 33- 23%, and in Melanoma of 40-50% in classes with higher scores. Conclusions: we confirm the precious contribution of the DS-GPA in correct selection of patients with brain metastases, and encourage the use of special technologies in properly selected patients.