Cost-Effectiveness Analysis of Stereotactic Ablative Radiation Therapy in Patients With Oligometastatic Cancer

The Stereotactic Ablative Radiation therapy for Comprehensive Treatment of Oligometastatic Tumors phase 2 randomized clinical trial found that stereotactic ablative radiation therapy (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 with standard therapy alone among cancer patients with oligometastatic disease.

We constructed a Markov model to simulate treatment with stereotactic ablative radiation therapy or standard therapy among patients with oligometastatic cancers. The model derived transition probabilities from Stereotactic Ablative Radiation therapy for Comprehensive Treatment of Oligometastatic Tumors clinical trial data to estimate risks of toxicity, disease progression and survival. Health care costs and health utilities were estimated from the literature. Probabilistic and one-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.

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, although 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.

The addition of SABR increased costs and improved quality adjusted survival, overall leading to a cost-effective treatment strategy for patients with oligometastatic cancer.