Cost-effectiveness Analysis of Stereotactic Ablative Radiotherapy in Patients with Oligometastatic Cancer

Abstract Purpose The SABR-COMET phase 2 randomized clinical trial found that stereotactic ablative radiotherapy (SABR) improved outcomes among cancer patients with oligometastatic disease. Yet, the cost of SABR along with the large number of patients with oligometastatic disease raises the important question of value. This study sought to evaluate the cost-effectiveness of the addition of SABR compared to standard therapy alone among cancer patients with oligometastatic disease. Methods We constructed a Markov model to simulate treatment with stereotactic ablative radiotherapy or standard therapy among patients with oligometastatic cancers. The model derived transition probabilities from SABR-COMET clinical trial data to estimate risks of toxicity, disease progression and survival. Healthcare costs and health utilities were estimated from the literature. Probabilistic and 1-way sensitivity analyses evaluate model uncertainty. Cost-effectiveness was estimated from both the health care sector and societal perspectives with an incremental cost-effectiveness ratio (ICER) defined as dollars per quality-adjusted life year (QALY). An ICER less than $100,000/QALY was considered cost-effective. One-way and probabilistic sensitivity analyses were used to examine model uncertainty. Results The addition of SABR increased total costs by $54,260 (health care sector perspective) or $72,799 (societal perspective) and improved effectiveness by 1.88 QALYs compared with standard therapy, leading to an ICER of $28,906/QALY (health care sector perspective) or $38,783/QALY (societal perspective). The model was modestly sensitive to assumptions about tumor progression, though the model was not sensitive to assumptions about survival or cost of treatment. Probabilistic sensitivity analyses demonstrated that SABR was the cost-effective treatment option 99.8% (health care sector perspective) or 98.7% (societal perspective) of the time. Conclusion The addition of SABR increased costs and improved quality adjusted survival, overall leading to a cost-effective treatment strategy for patients with oligometastatic cancer.