Feasibility and Efficacy of Local Radiotherapy With Concurrent Novel Agents in Patients With Multiple Myeloma

IntroductionThis study evaluated the safety and efficacy of radiotherapy (RT) with concurrent novel agents (NAs), cytotoxic therapy (CTx), or both in the management of osteolytic bone lesions in multiple myeloma (MM).Patients and MethodsA total of 39 patients with MM received RT to 64 different bone sites during the 2007-2012 period, with a dose of 8 to 37.5 Gy (mean, 26.8 Gy) delivered in 1 to 15 fractions (median, 10 fractions). Of these patients, 21 also received concurrent NAs or CTx. Pain response, M protein and κ light chain response, and adverse events were evaluated.ResultsRT was completed in 35 of 39 patients (89.7%) in this study. Pain relief was observed in 30 of 31 patients (96.7%). Hematologic toxicity (grade 3 or 4 by the Radiation Therapy Oncology Group system) was seen in 43.2% of treated patients, and NA therapy was stopped in 2 patients owing to grade 4 toxicity. RT adverse effects resolved at 4 to 6 weeks posttreatment. Changes in pre- and posttreatment levels of M protein trended toward significance in patients treated with RT + systemic therapy (ST) versus. RT alone (ΔM ProteinRT+ST = 5.6 g/L; ΔM ProteinRT = 0 g/L; P = .089).ConclusionTreating MM with RT concurrently with CTx including NAs was safe and well tolerated in the majority of patients (14 of 16 [87.5%] for those taking NAs and 19 of 21 [90.5%] for all patients). Excellent clinical pain response (> 95%) was also seen in patients regardless if they were treated with RT + ST or RT alone.