Percutaneous Microwave Ablation and Cementoplasty: Clinical Utility in the Treatment of Painful Extraspinal Osseous Metastatic Disease and Myeloma

OBJECTIVE. The purpose of this study was to review the efficacy and durability of pain control and local tumor control using microwave ablation and cementoplasty in treating extraspinal osseous tumors. Painful osseous metastases are a common cause of cancer-related morbidity. Percutaneous thermal ablation presents an attractive minimally invasive option in this vulnerable patient group. MATERIALS AND METHODS. A retrospective review included 65 patients (35 men, 30 women) with 77 tumors who underwent image-guided microwave ablation and cementoplasty at a tertiary referral academic center over 18 months. Procedural efficacy was determined with a visual analog scale before the procedure and 24 hours, 2-4 weeks, and 20-24 weeks after the procedure. Locoregional control was assessed at follow-up cross-sectional imaging. RESULTS. The 77 tumors were in the following locations: ilium, 38; acetabulum on supraacctabular region, 23; femur, five; humerus, four; shoulder, four; sternum, three. The tumors were 15 multiple myelomas and metastases from cancers of the following organs: colon, nine; lung, 15; breast, 12; thyroid, seven; prostate, three; and kidney, four. Complete, successful ablation of all 77 tumors was achieved. Mean ablation time was 6 minutes 15 seconds (SD, 12 seconds), and mean energy used was 5.49 (SD, 2.97) kJ. The mean visual analog scale scores were 6.32 (SD, 1.94) before the procedure, 1.01 (SD, 1.24) at 24 hours, 1.71 (SD, 1.31) at 2-4 weeks, and 2.01 (SD, 1.42) at 20-24 weeks. Follow-up imaging at 20-24 weeks showed no local progression in 42 of 65 patients (64.6%). Six patients died 24-52 weeks after the procedure. No procedure-related complications were reported. CONCLUSION. Microwave ablation is efficacious in alleviating pain due to osseous metastases. The modality has promise for locoregional control of metastases, particularly in the context of oligometastatic (limited disseminated) disease.