This study is being done to answer the following question: Can a patient’s life be extended by adding a type of radiation therapy called whole-brain radiation therapy that avoids the hippocampus to preserve memory plus the medication memantine that is FDA approved to treat dementia to the usual treatment?
This study aims to find out if adding Hippocampal-Avoidant Whole Brain Radiotherapy and memantine is better or worse than the usual approach for your brain cancer.
- Patients must have developed their first or second distant brain relapse(s) at least 8 weeks after upfront SRS and within 21 days prior to randomization
- Brain metastasis velocity (BMV) since upfront SRS must be ≥4 brain metastases/year.
- Pathologically (histologically or cytologically) proven diagnosis of non-small cell lung cancer, melanoma, breast cancer, renal cell carcinoma, or gastrointestinal cancer within 10 years prior to randomization.
- Prior WBRT or prophylactic cranial irradiation.
- Local relapse of metastasis previously treated with upfront SRS (i.e., relapse outside previously SRS-treated metastases is allowed)
- Brain metastases from primary germ cell tumor, small cell carcinoma, or lymphoma.
Participants will either get treatment with SRS plus HA-WBRT and memantine, or treatment with SRS alone.
Participants will receive the usual treatment, Stereotactic radiosurgery, which delivers a high dose of radiation only to the small areas of cancer in the brain and avoids the surrounding normal brain tissue. SRS is a single treatment over one day (or in some cases a few days) as an outpatient procedure.
If participants receive HA-WBRT, they will receive it 5 days per week Monday through Friday for about 2 weeks as an outpatient procedure. Whole brain radiation therapy delivers a low dose of radiation to the entire brain including the normal brain tissue. Hippocampus avoidance during whole-brain radiation therapy (HA-WBRT) decreases the amount of radiation that is delivered to the hippocampus which is a brain structure that is important for memory. The medicine memantine is also often given with whole brain radiation therapy because it may decrease the risk of side effects of radiation on thinking and memory. Participants will receive memantine as a tablet by mouth for 6 months.
After treatment, the doctor and study team will watch participants for side effects and follow their condition. They will check every 2 to 3 months for at least 1 year after finishing SRS. If the participants are receiving memantine, the doctor will continue to see them in the clinic as needed.