Stereotactic Radiotherapy Versus Hippocampal-Avoidance Whole Brain Radiation

As patients live longer with advanced cancer, brain metastases are now becoming a frequent and even chronic condition managed with a variety of systemic agents and local treatments. Radiotherapy plays a key role in treatment of intracranial lesions.

Whole brain radiation therapy (WBRT) has the benefit of treating both imaging-apparent and microscopic disease. This approach can offer general intracranial disease control, but can damage healthy brain tissue, resulting in neurocognitive impairment associated with irradiation of the hippocampus.

The innovation of hippocampal-avoidance WBRT (HA-WBRT) maintains global intracranial disease control while reducing neurocognitive decline relative to traditional WBRT, even in the setting of the neuroprotectant memantine (0.74; 95% CI, 0.58-0.95; P = .02), making HA-WBRT a standard-of-care approach to appropriate patients. Nevertheless, HA-WBRT requires several weeks of daily treatments and often time off systemic therapy.

Conversely, stereotactic radiation (SRT) is given over 1 to 3 treatments to the visible lesions, allowing for higher radiation dose, better focal disease control, and sparing of healthy brain tissue, which further reduces neurocognitive toxic effects.