Radiotherapy for cranial and brain metastases from prostate cancer: a systematic review

Intracranial metastasis from prostate cancer is rare. As treatment of castration-resistant prostate cancer improves, the incidence of men with intracranial metastasis from prostate cancer is increasing. Radiation therapy for treatment of intracranial metastasis from prostate cancer is systematically reviewed. A comprehensive review examining peer-reviewed, English language articles from 1990 to 2015 was performed on multiple databases, yielding 1274 articles. These articles were reviewed and selected for studies that met the following inclusion criteria: (1) patients with intracranial metastases from prostate cancer; (2) patients underwent radiation therapy as primary or adjuvant therapy; (3) the sample size of patients was larger than 2. All studies that met inclusion criteria utilized whole-brain radiation therapy (WBRT) in at least one patient. Other treatment regimens included stereotactic radiosurgery (SRS), surgical resection followed by WBRT, as well as concurrent cabazitaxel and WBRT. The range of average time from initial diagnosis of prostate cancer to diagnosis of brain metastasis was 29-45 months. The range of reported median survival time after WBRT was 4-9 months, whereas median survivals after SRS ranged from 9 to 13 months. Intracranial metastases from prostate cancer occur late in the disease process, and are increasing as novel therapies for metastatic disease prolong survival. The reviewed literature suggests that outcomes of patients with prostate cancer intracranial metastases appear similar to those of intracranial metastases from other histologies. Prospective examinations of systemic therapies that cross the blood-brain barrier in conjunction with targeted radiotherapy appear warranted for this increasingly common clinical problem.