Radiation for Multiple Myeloma in the Era of Novel Agents: Indications, Safety, and Dose Selection.

Survival outcomes for multiple myeloma (MM) have drastically improved over the past two decades with the advent of highly effective biologic agents and integration of autologous stem cell transplant (ASCT) for select patients. Despite these advances, MM remains an incurable disease and duration of remission decreases with each relapse. Palliative radiotherapy (RT) for MM, including treatment of pain, relief of compression, and prevention of fracture, is highly effective and generally well tolerated. Though RT can be delivered concurrently with biologic agents, caution should be exercised for potential added hematologic toxicity that may disrupt systemic therapy, especially in heavily pretreated patients, who have limited bone marrow reserve. In this review, we discuss the safety of RT with biologic agents (proteasome inhibitors, immunomodulators, monoclonal antibodies), review indications for palliative RT in MM, and present a framework for how to personalize RT based on goals of treatment, classification of uncomplicated versus complicated lesions, and patient and lesion characteristics. Additionally, we discuss the emerging role of bridging RT prior to chimeric antigen receptor (CAR) T-cell therapy.