Stereotactic Radiosurgery and Stereotactic Fractionated Radiotherapy in the Management of Brain Metastases

Abstract

The management of brain metastases (BM) remains an important and complex issue in the treatment of cancer-related neurological complications. BM are particularly common in patients diagnosed with lung, melanoma, or breast cancer. Over the past decade, therapeutic approaches for the majority of BM patients have changed. Considering and addressing the fact that patients with BM are living longer, the need to provide effective local control while preserving quality of life and neurocognition is fundamental. Over the past decade, SRS and SRT have become a more commonly chosen treatment option for BM. Despite significant advances in the treatment of BM, numerous questions remain regarding patient selection and optimal treatment sequencing. Clinical trials are critical to advancing our understanding of BM, especially as more therapeutic alternatives become available. Therefore, it is imperative for interdisciplinary teams to improve their understanding of the latest advances in SRS-SRT. This review aims to comprehensively explore SRS and SRT as treatments for BM, covering clinical considerations in their application (e.g., patient selection and eligibility), managing limited and multiple intact BM, addressing brainstem metastases, exploring combination therapies with systemic treatments, and considering the health economic perspective.

Keywords: brain intracranial metastases; review; stereotactic fractionated radiotherapy; stereotactic radiosurgery.

Figure 1

Illustration of a case of multiple brain metastases from lung cancer without drivers’ mutation treated in August 2018. In February 2021, he developed 16 BM. He had four sessions of SRS (20 Gray to the 70% isodose line): PTV_01 in February 2021 (n = 16); PTV_02 in May 2021 (n = 3); PTV_03 in August 2021 (n = 2); and PTV_04 in October 2021 (n = 3). He had no new brain metastases until the last MRI in April 2022. (A): three-dimensional image of the brain and the target BM: red: PTV_01; orange: PTV_02; pink: PTV_03; green: PTV_04. (B): axial CT-scan slice, showing the patient’s dose-color-wash, (C): Dose-Volume Histogram.

Figure 2

Illustration of the case of a single BSM from a melanoma without drivers’ mutation treated with one course of SRS (24 Gray to the 70% isodose line). (A): axial–sagital CT-scan and MRI slice, showing the target lesion and the patient’s dose-color-wash; (B): Dose-Volume Histogram.