Uptake and outcomes of intensity-modulated radiation therapy for uterine cancer.

Objective: While intensity-modulated radiation therapy (IMRT) allows more precise radiation planning, the technology is substantially more costly than conformal radiation and, to date, the benefits of IMRT for uterine cancer are not well defined. We examined the use of IMRT and its effect on late toxicity for uterine cancer.

Methods: Women with uterine cancer treated from 2001 to 2007 and registered in the SEER-Medicare database were examined. We investigated the extent and predictors of IMRT administration. The incidence of acute and late-radiation toxicities was compared for IMRT and conformal radiation.

Results: We identified a total of 3555 patients including 328 (9.2%) who received IMRT. Use of IMRT increased rapidly and reached 23.2% by 2007. In a multivariable model, residence in the western U.S. and receipt of chemotherapy were associated with receipt of IMRT. Women who received IMRT had a higher rate of bowel obstruction (rate ratio=1.41; 95% CI, 1.03-1.93), but other late gastrointestinal and genitourinary toxicities as well as hip fracture rates were similar between the cohorts. After accounting for other characteristics, the cost of IMRT was $14,706 (95% CI, $12,073 to $17,339) greater than conformal radiation.

Conclusion: The use of IMRT for uterine cancer is increasing rapidly. IMRT was not associated with a reduction in radiation toxicity, but was more costly.