The role of radiation therapy for multiple myeloma in the era of novel agents.

Abstract

e18557 Background: Radiation therapy (RT) is one of the treatment modalities of multiple myeloma (MM), and it is commonly used in the treatment of pain, bone fractures, and spinal cord compression. We conducted a retrospective study of the use and clinical outcomes of RT in patients with MM diagnosed after the introduction of the three novel therapeutic agents: thalidomide, lenalidomide, and bortezomib. Methods: We retrospectively reviewed the medical records of 145 MM patients seen at the Penn State Hershey Cancer Institute in 2008. Results: Forty-six (32%) MM patients received RT, and 21 of them at more than one site, for a total number of 78 irradiated sites. The indications for local RT were palliation of bone pain (n= 49 sites), pathological fractures (n= 18), spinal cord compression (n= 7), and control of extramedullary disease (n= 4). The most common site of RT was the thoracic spine (18%). Spine and pelvis constituted together 53% of irradiation sites. RT was given within 6 months after the diagnosis of MM in 74% of cases, and at baseline (i.e., before starting systemic therapy) in 41% of cases. The mean number of stem cells collected for autologous transplantation was 12.6 x106 in 20 patients who received RT to spine and/or pelvis before the stem cell collection, and 26.2 x106 in 66 patients who did not, but the difference did not reach statistical significance (p=0.09). Conclusions: Despite the recent introduction of novel biological agents for the treatment of MM, RT continues to be a commonly utilized therapeutic strategy in the management of this disease. RT to spine and/or pelvis does not seem to significantly compromize the collection of peripheral blood stem cells for autologous transplantation. No significant financial relationships to disclose.