Trends in Utilization and Medicare Spending on Shorter vs. Longer Radiotherapy Courses for Breast and Prostate Cancer

Abstract

Evidence based research supports shorter, similarly efficacious, and potentially more cost-effective hypofractionated treatment regimens in many clinical scenarios for breast cancer (BC) and prostate cancer (PC). However, practice patterns of hospital-affiliated and standalone facilities vary considerably. We used the most recent Centers for Medicare and Medicaid Services data to assess trends in radiotherapy (RT) costs and practice patterns among episodes of BC and PC. We performed a retrospective cohort analysis of all external beam episodes for BC and PC from 2015-2019. For patients with BC, receipt of shorter-course RT (SCRT) was defined as receiving 11-20 fractions of external beam radiation therapy (including IMRT), and conventional RT as >20 fractions. For patients with PC, SBRT was defined as receipt of <10 fractions and moderate hypofractionation as 10-30 fractions (SCRT defined as SBRT and moderate hypofractionation), and >30 fractions for conventional RT. Total Medicare spending were defined as the sum of winsorized payment for professional and technical services furnished during the episode in 2019 dollars. Multivariable logistic regression defined adjusted odds ratios (ORs) of receipt of SCRT over conventional RT by treatment modality, age, year of diagnosis, type of practice, as well as a time*treatment setting interaction term. Medicare spending was evaluated using multivariable linear regression controlling for duration of RT regimen (SCRT vs conventional) in addition to the covariables above. Of 47,283 BC episodes and 45,917 PC episodes, 23,705 (50.13%) and 9,125 (19.87%) were SCRT, respectively. Median total spending for SCRT among BC episodes was $9,324 (IQR, $7,916-$10,921) vs. $13,372 (IQR, $11,511-$15,283) for conventional RT. Among PC episodes, median total spending was $12,917 (IQR, $9,551-$15,271) for SBRT, $18,944 (IQR, $16,530-$20,615) for moderate hypofractionation, and $26,935 (IQR, $25,062-$28,959) for conventional RT. For both cancers, total episode spending was reduced with SCRT utilization [(BC adjusted β, -$4,200; p<0.001), (PC adjusted β, -$8,747; p<0.001)], older age, and non-IMRT-based treatment. On logistic regression, receipt of SCRT was associated with older age among both BC and PC episodes (p<0.001), as well as treatment at hospital-affiliated over freestanding sites [(BC OR [95% CI], 1.41 [1.29-1.54], p<0.001), (PC OR, 1.64 [1.39-1.94], p<0.001)]. In this evaluation of all BC and PC RT episodes from 2015-2019, we found that shorter-course RT resulted in increased cost-savings vs. conventional RT. SCRT was also more common in hospital-affiliated sites. Further research is needed to devise payment incentives that encourage SCRT when clinically applicable in the two most common sites treated with RT, and to prospectively study cost-effective hypofractionation in other disease sites.