Stereotactic Radiation Therapy Outperforms Whole-Brain Radiation for Brain Metastases

A recent phase III randomized trial has demonstrated that stereotactic radiation therapy, which targets individual brain tumors, can be more beneficial for patients with brain metastases compared to whole-brain radiation. This approach has the potential to enhance patients' quality of life by maintaining cognitive functions, an essential aspect for those undergoing cancer treatment. The study, led by Dr. Ayal Aizer, Director of Central Nervous System Radiation Oncology at Brigham and Women's Hospital, has been published in JAMA.

Traditionally, patients with a limited number of brain metastases (four or fewer) have been treated with stereotactic radiation due to its ability to improve cognitive function without affecting overall survival, unlike whole-brain radiation. However, for patients with a greater number of brain tumors, whole-brain radiation has been the standard treatment. Recent advancements have introduced hippocampal-avoidance techniques in whole-brain radiation, which are associated with better cognitive outcomes than traditional whole-brain radiation.

The study by researchers at Mass General Brigham Cancer Institute included 196 patients with five to 20 brain metastases from four treatment centers. These patients were randomly assigned to receive either stereotactic radiation or hippocampal-avoidance whole-brain radiation. Outcomes were assessed based on a system that measured both the severity of symptoms and the effect on daily living activities.

Six months post-treatment, patients who received stereotactic radiation reported improvements in symptom severity scores, while those receiving whole-brain radiation with hippocampal-avoidance experienced a decline in their scores. Additionally, the group treated with stereotactic radiation maintained better overall performance status and exhibited greater dependency in daily activities. Cognitive testing further corroborated that stereotactic radiation recipients had superior outcomes.

In terms of survival, no significant differences were noted between the groups. However, patients who underwent stereotactic radiation experienced a higher incidence of new metastases (45% vs. 24% at one year). Most of these new metastases were successfully managed with repeat stereotactic treatments. Notably, only 3.2% of patients experienced a recurrence of a previously treated tumor with stereotactic radiation, compared to 39.5% in the whole-brain radiation cohort.

Some limitations of the study included the inability to blind investigators to treatment assignments and potential biases due to the high mortality rates associated with multiple brain metastases. The research received funding from Varian, a Siemens Healthineers Company.