Palliation of painful metastatic disease involving bone with imaging-guided treatment: Comparison of patients' immediate response to radiofrequency ablation and cryoablation

OBJECTIVE. The purpose of this article was to compare periprocedural analgesic requirements and hospital length of stay for treatment of patients with painful metastatic tumors involving bone using either percutaneous radiofrequency ablation (RFA) or cryoablation. MATERIALS AND METHODS. A retrospective review was conducted of patients who underwent either imaging-guided cryoablation or imaging-guided RFA for painful metastatic tumors involving bone. The total analgesic usage for 24 hours after the procedure was expressed as a standard morphine-equivalent dose. Analgesic usage at admission served as a baseline for comparison. Total hospital stay was used as an additional measurement of procedure- related morbidity. RESULTS. Fifty-eight patients underwent either cryoablation (n = 36) or RFA (n = 22) for painful metastatic tumors involving bone. Twenty-two primary tumors were treated. The most common treatment site was the pelvis (n = 31). There was no significant difference between the two groups with regard to tumor histologic type (p = 0.52) and location (p = 0.72). The median tumor diameter was 4.4 cm for the cryoablation group and 5.0 cm for the RFA group (p = 0.63). Pretreatment pain scores, measured on a scale of 0 to 10, were not significantly different between the two groups: 6.5 for cryoablation and 6.0 for RFA (p = 0.78). Analgesic use in the 24 hours immediately after the procedure decreased significantly by 24 morphine-equivalent doses after cryoablation, whereas it increased by a median of 22 morphine-equivalent doses after RFA (p = 0.03). Total hospital length of stay for patients undergoing cryoablation was a median of 2.5 days less than that for patients receiving RFA (p = 0.003). CONCLUSION. The use of cryoablation compared with RFA is associated with a greater reduction in analgesic dose and shorter hospital stays after the procedure in the perioperative time frame.