Fractionated Stereotactic Radiotherapy for Brain Metastases: A Moroccan Multicenter Experience

Stereotactic radiotherapy is currently an essential therapeutic tool in the treatment of brain metastases. The aim of our study was to report a multicenter Moroccan experience on stereotactic radiotherapy using linear accelerators in the treatment of brain metastases.

We conducted a multicenter retrospective study that included 130 patients treated at five centers in Morocco for brain metastases during the period between January 2021 and December 2024. All patients received fractionated stereotactic radiotherapy delivered by a linear accelerator. Statistical analysis of the data was performed using Jamovi version 2.3.

We collected 130 patients with 248 treated brain metastases. The mean age was 58.4 (24-88) with a female predominance (59.2%). The most common primary tumor was lung cancer (77 patients, 59.2%), followed by breast cancer (29 patients, 22.3%) and colorectal cancer (eight patients, 6.1%). Adenocarcinoma was the predominant histological type (104 patients, 73.5%), followed by squamous cell carcinoma (11 patients, 8.5%). The majority of patients had fewer than three metastases. The mean tumor size was 23.8 mm, and the median volume was 8 cc (0.05-89). The two most prescribed irradiation regimens were 3 × 9 Gy and 5 × 6 Gy (37 cases or 28%). The lowest biologically effective dose with α/β = 10 (BED10) was 35.7 in five patients (4%), with a mean BED10 of 51. Follow-up data were available for 59 patients. After a median follow-up of 10.9 months (2-36 months) since the onset of brain metastases, overall survival at 24 months was 48.2%.

Stereotactic radiotherapy remains an effective treatment for local control of brain metastases. However, further studies are needed to homogenize practices and establish guidelines and procedures to improve long-term results.