Abstract:
Objective To evaluate the efficacy and safety of CyberKnife radiosurgery for the treatment of brainstem metastases.
Methods We retrospectively reviewed the medical records of 55 brainstem metastases in 49 consecutive adult patients treated with CyberKnife at Tianjin Medical University Cancer Hospital between January 2013 and January 2018. Overall survival and local control rate after treatment were analyzed. The variables included sex, age, tumor location, tumor size, resection extent, primary pathology, KPS score and with or without whole brain radiotherapy.
Results The median size of the treated lesions was 1.96 (0.1-15.6) cm3. The prescribed dose was (8-40) Gy, delivered by 1-5 days. The median single session equivalent dose (α/β=10) was 18.2 (8-23.7) Gy. The median maximum single session equivalent dose was 25.2 (11.8-37.4) Gy. Of 55 treated lesions, the local control rate was 87.3% (15 CR, 27 PR and six SD). The median survival time was 14 months and the median progression-free survival time was 17.4 months. The overall survival ratios after treatment at 0.5, 1, and 2 years were 75.5%, 55.1%, and 28.6%, respectively.
Conclusions CyberKnife radiotherapy is a safe and effective treatment for patients with brainstem metastases. CyberKnife allows for hypofractionation or multisession treatments, which may reduce complications and adverse effects involving surrounding brain tissue while enabling the treatment of larger lesions.