This phase III trial compares the effect of stereotactic radiosurgery to standard of care memantine and whole brain radiation therapy that avoids the hippocampus (the memory zone of the brain) for the treatment of small cell lung cancer that has spread to the brain. Stereotactic radiosurgery is a specialized radiation therapy that delivers a single, high dose of radiation directly to the tumor and may cause less damage to normal tissue. Whole brain radiation therapy delivers a low dose of radiation to the entire brain including the normal brain tissue. Hippocampal 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 drug, memantine, is also often given with whole brain radiotherapy because it may decrease the risk of side effects related to thinking and memory. Stereotactic radiosurgery may decrease side effects related to memory and thinking compared to standard of care HA-WBRT plus memantine.
Pathologically (histologically or cytologically) proven diagnosis of small cell lung cancer within 5 years of registration. If the original histologic proof of malignancy is greater than 5 years, then pathological (i.e., more recent) confirmation is required (e.g., from a systemic or brain metastasis);
Patients with de novo or recurrent small cell lung cancer are permitted.
Brain metastases =< 4 cm in largest diameter and outside a 5-mm margin around either hippocampus must be visible on contrast-enhanced magnetic resonance imaging (MRI) performed =< 21 days prior to study entry.
The total tumor volume must be 30 cm^3 or less. Lesion volume will be approximated by measuring the lesion's three perpendicular diameters on contrast enhanced, T1-weighted MRI and the product of those diameters will be divided by 2 to estimate the lesion volume (e.g. xyz/2). Alternatively, direct volumetric measurements via slice by slice contouring on a treatment planning software package can be used to calculate the total tumor volume.
Planned infusion of cytotoxic chemotherapy on the same day as SRS or HA-WBRT treatment. Patients may have had prior chemotherapy. Concurrent immunotherapy is permitted.
For patients receiving fractionated SRS on an every-other-day basis, planned infusion of cytotoxic chemotherapy is not permitted between SRS treatments.
Brainstem metastasis > 10 cm^3
Prior allergic reaction to memantine.
NRG Oncology
Lead sponsor
National Cancer Institute (NCI)
Collaborator