Toxicity and cost-effectiveness analysis of intensity modulated radiation therapy versus 3-dimensional conformal radiation therapy for postoperative treatment of gynecologic cancers

• IMRT is associated with significant reductions in late toxicity compared to 3DCRT, without compromising clinical outcome.
• While the reductions in late toxicity come at an increased cost, IMRT becomes more cost-effective over time.
• Long-term survivors may realize the most economic benefit of post-hysterectomy IMRT.

ObjectiveTo evaluate toxicity and cost-effectiveness of intensity modulated radiation therapy (IMRT) versus 3-dimensional conformal radiation therapy (3DCRT) in the postoperative treatment of uterine and cervical cancer.MethodsBetween 2000 and 2012, eighty patients at our institution received post-hysterectomy 3DCRT (46) or IMRT (34) for uterine or cervical cancer. Baseline characteristics, outcome, and ≥ CTCAE grade 2 toxicities were compared between the two groups. Predictors of toxicity-free survival were identified. A decision analysis model was designed to capture individual health states at 1, 2, and 3 years after treatment. Micro-costing technique and estimated quality-adjusted life years (QALYs) were used to calculate incremental cost-effectiveness ratio (ICER).ResultsUtilization of IMRT increased from 25% (2005–2007) to 75% (2008–2012). Recurrence-free and overall survival rates were not different between the two groups. Toxicity rates were reduced with IMRT versus 3DCRT (HR 0.42, p = 0.04). Women who received IMRT had numerically lower rates of late gastrointestinal and genitourinary toxicity and significantly lower rates of late overall toxicity at 3 years (16% vs. 45%, p = 0.04). On univariate analysis, IMRT was associated with decreased late toxicity (HR 0.43, p = 0.04). Treatment costs were higher and toxicity costs were lower with IMRT. IMRT had an ICER of $235,233 (year 1), $114,270 (year 2), and $75,555 (year 3) per QALY gained.ConclusionIMRT is associated with reduced late overall toxicity compared to 3DCRT without compromising clinical outcome. IMRT is not cost-effective during the early chronic toxicity phase, but it becomes more cost-effective over time.