Brain metastasis occurs in up to 20-40% of patients with advanced malignancy, and its incidence is further rising as result of increased accessibility of more sensitive neuroimaging.
Historically, brain metastasis is regarded an ‘end-of-life event’, associated with very poor prognosis and limited treatment options. For decades, whole brain radiotherapy (WBRT) has been considered a standard of care, despite lack of benefit in overall survival or quality of life across clinical trials. On the other hand, it is associated with negative impact on long term neurocognitive function.
In recent years, there has been rapid evolution in the treatment landscape of systemic therapy, with emergence of novel biomarker-directed treatment options, allowing improvement in disease control and survival for patients with brain metastasis. As patients survive longer, they are also vulnerable to treatment toxicity. In the modern era of anti-cancer treatment, personalised care to maximise the therapeutic ratio to improve intracranial control and minimise treatment-related toxicity and maintain neurocognitive function is paramount.
Radiotherapy treatment paradigm has shifted to modern techniques such as stereotactic radiosurgery (SRS), producing excellent local tumour control and superior neurocognitive preservation and quality of life compared to WBRT, and has gained popularity in clinical practice in the past decade. Furthermore, emerging clinical evidence and advancement in radiotherapy technology support SRS treatment for suitable patients with more extensive intracranial disease. Other neurocognitive protection strategies such as WBRT with hippocampal avoidance and memantine also produce encouraging treatment results.
In real-world practice, advanced radiotherapy treatment requires careful case selection, and calls for high precision in the process of radiotherapy treatment planning, quality assurance and image guidance, under the concerted effort of a multidisciplinary team. Here, we discuss on the available evidence for modern radiotherapy treatment strategies for brain metastasis, highlight on the procedures in radiotherapy planning, and share on local treatment experience.
