Cost-Effectiveness of Prophylactic Cranial Irradiation vs MRI Surveillance for Small Cell Lung Cancer

A recent study revealed that prophylactic cranial irradiation is not cost-effective compared with MRI surveillance for extensive-stage small cell lung cancer (SCLC; Int J Radiat Oncol Biol Phys. 2021; S0360-3016[21]00477-6. doi:10.1016/j.ijrobp.2021.04.049).

“Owing to conflicting prospective data, controversy exists regarding prophylactic cranial irradiation in extensive-stage [SCLC],” wrote Hayeon Kim, PhD, DABR, Department of Radiation Oncology, UPMC Hillman Cancer Center, Pittsburgh, Pennsylvania, and colleagues.

This study evaluated the cost-effectiveness of prophylactic cranial irradiation compared with magnetic resonance imaging (MRI) surveillance in this patient population. Cost-effectiveness of the treatment approaches were based on currently available evidence and in the context of the proposed Centers for Medicare & Medicaid Services alternative payment model.

A Markov state transition model  was developed to compare MRI surveillance alone vs prophylactic cranial irradiation for extensive-stage SCLC. Medicare reimbursement data from 2019 was used to dictate cost estimates. The incremental cost-effectiveness ratio (ICER) was used to compare strategies with effectiveness in quality-adjusted life years (QALYs). The willingness-to-pay threshold was $100,000 per QALY gained.

The model revealed, in the base-case scenario, that prophylactic cranial irradiation was not cost-effective, with an ICER of $168,456 per QALY gained compared with MRI surveillance alone. The variation of overall survival and cognitive decline rates were sensitive factors between the two groups.

Model results were nearly cost-effective with prophylactic cranial irradiation when all patients received hippocampal-avoidance prophylactic cranial irradiation.

“[Prophylactic cranial irradiation] was not found to be cost-effective within this model compared with MRI surveillance alone, owing to the neurocognition decline effect of [prophylactic cranial irradiation] based on available evidence,” wrote Dr Kim and colleagues, concluding “Hippocampal-avoidance prophylactic cranial irradiation may be a potential cost-effective strategy for [extensive-stage] SCLC, with confirmation expected after an ongoing prospective clinical trial… which includes assessments of cognitive function.”—Marta Rybczynski