Cognitive Outcome After SRS or WBRT in Patients With Multiple Brain Metastases (CAR-Study B)

A Prospective Randomized Study to Compare Cognitive Outcome After Stereotactic Radiosurgery or Whole Brain Radiation Therapy in Patients With 11-20 Brain Metastases

Whole Brain Radiation Therapy (WBRT) has long been the mainstay of treatment for patients with multiple brain metastases (BM). Meanwhile, Gamma Knife radiosurgery (GKRS) has been increasingly employed in the management of multiple BM to spare healthy tissue. Hence, GKRS is expected to cause fewer cognitive side effects than WBRT. Treatment of multiple BM without cognitive side effects is becoming more important, as more patients live longer due to better systemic treatment options. There are no published randomized trials yet directly comparing GKRS to WBRT in patients with multiple BM, including objective neuropsychological testing.

CAR-Study B is a prospective randomized trial comparing cognitive outcome after GKRS or WBRT in eligible patients with 11-20 BM.

CAR-Study B is a prospective randomized trial comparing cognitive outcome after GKRS or WBRT in eligible patients with 11-20 BM on a triple dose gadolinium-enhanced MRI-scan. Neuropsychological assessment will be performed at baseline and at 3, 6, 9, 12 and 15 months after treatment. Follow-up assessments will be combined with 3-monthly MRI-scans.

Patients will be randomized to either GKRS or WBRT. Groups will be balanced at baseline (prior to radiotherapy), taking into account several (stratification) factors that may influence cognitive functioning over time, such as: total tumor volume in the brain, systemic treatment, KPS, age, histology, and baseline HVLT-R total recall score.

Inclusion Criteria:

• Histologically proven malignant cancer
• 11-20 newly diagnosed brain metastases on a triple dose gadolinium-enhanced MRI-scan
• Maximum total tumor volume ≤ 30 cm3
• Lesion ≥ 3 mm from the optic apparatus
• Age ≥ 18 years
• Karnofsky Performance Status (KPS) ≥ 70
• Anticipated survival > 3 months

Exclusion Criteria:

• No prior histologic confirmation of malignancy
• Primary brain tumor
• A second active primary tumor
• Small cell lung cancer (SCLC)
• Lymphoma
• Leukemia
• Meningeal disease
• Progressive, symptomatic systemic disease without further treatment options
• Prior brain radiation
• Prior surgical resection of BM
• Cardiovascular accident (CVA) < 2 years ago
• Additional history of a significant neurological or psychiatric disorder
• Contra indications to MRI or gadolinium contrast
• Underlying medical condition precluding adequate follow-up
• Participation in a concurrent study in which neuropsychological testing and/or health-related QOL assessments are involved
• Lack of basic proficiency in Dutch
• IQ below 85
• Severe aphasia
• Paralysis grade 0-3 according to MRC scale (Medical Research Council)