Computed Tomography-Guided Microwave Ablation Combined with Osteoplasty for the Treatment of Bone Metastases: A Multicenter Clinical Study

Purpose: To evaluate the efficacy and safety of combined microwave ablation (MWA) and osteoplasty as a palliative therapy for painful bone metastases. Materials and Methods: As an extension of a previous limited single-center study, a retrospective review was conducted for 147 patients (77 male, 70 female) with painful bone metastases who underwent MWA combined with osteoplasty. In total, 102 (69.4%), 41 (27.9%), and 4 (2.7%) patients had spinal metastases, extraspinal metastases, and both, respectively. Treatment efficacy was determined by comparing visual analog scale (VAS) scores, daily morphine equivalent opioid consumption, and Oswestry disability index (ODI) scores before treatment and during the follow-up period (mean follow-up, 9.8 months; range 3-16). Results: The mean VAS score significantly declined from 6.4 +/- 2.3 before treatment to 3.2 +/- 2.1, 1.9 +/- 1.6, 1.8 +/- 1.6, 1.8 +/- 1.6, and 1.9 +/- 1.6 at 24 hours, 1 week, 4 weeks, 12 weeks, and 24 weeks after treatment, respectively (P < .01). Furthermore, the mean daily morphine equivalent opioid consumption was significantly reduced from 81.5 +/- 32.8 mg before treatment to 40.0 +/- 20.6, 32.4 +/- 10.2, 26.4 +/- 10.0, 21.5 +/- 8.3, and 19.3 +/- 7.4 mg. The mean ODI score also declined after treatment (P < .0001). Major complications occurred in 4 of 147 patients, with 1 pathologic fracture, 1 nerve injury, and 2 mild skin infections. Minor cement leakages were observed at 69 sites (32.8%). Conclusions: MWA combined with osteoplasty is an effective and safe treatment for painful bone metastases.