Stereotactic Ablative Body Radiotherapy (SABR) versus Radiofrequency Ablation and cryoablation for Primary Renal Cell Carcinoma: an economic evaluation of the FASTRACK II trial

PURPOSE: The FASTRACK II trial demonstrated the safety and efficacy of SABR in patients with inoperable renal cell carcinoma (RCC). In this study, we investigated whether SABR was cost-effective compared with the thermal ablation strategies of radiofrequency ablation (RFA) and cryoablation (CA). METHODS AND MATERIALS: The cost-effectiveness analysis was conducted from an Australian public health care system perspective using data from Australian patients enrolled into the FASTRACK II trial and used estimates from the literature for the comparators. Health-related quality of life (HRQoL) was measured using the European Organisation for Research and Treatment of Cance Core Quality of Life questionnaire and converted to utility values using the Quality of Life Utility - Core 10 Dimensions instrument with Australian utility weights. HRQoL was analyzed using a mixed model for repeated measures. SABR costs were obtained from linked administrative data records and were analyzed using a generalized linear model. A 10-year time horizon was applied to a Markov model with health states of localized RCC, progression-free, local progression, metastasis, and death was developed. Outcomes were expressed as quality-adjusted life years, with the intent to estimate an incremental cost-effectiveness ratio. Deterministic and probabilistic sensitivity analyses were conducted. RESULTS: The mixed model for repeated measures showed that over the study duration, there was a decrease in HRQoL after SABR compared with baseline. After an initial decline, mean scores approached baseline but remained lower, largely because of changes in fatigue and dyspnea. The economic evaluation showed SABR was more effective and less costly than RFA and CA. SABR remained dominant in all deterministic sensitivity analyses, and the probabilistic sensitivity analysis showed that SABR had a higher cost than RFA in only 10% of iterations, remaining cost-effective. CONCLUSIONS: Our findings show that although there is an initial reduction in HRQoL post-SABR, it is more effective and less costly than RFA and CA in patients with inoperable RCC. From a cost-effectiveness perspective, it should be considered the treatment of choice for this population.