Abstract and Introduction
Abstract
Background Although intensity modulation of the radiation beam has been shown to lower toxic effects for patients receiving whole-breast irradiation, relatively simple techniques may suffice. It is thus controversial whether such treatment justifies billing for intensity-modulated radiation therapy (IMRT).
Methods We used the claims data to determine billing for IMRT from Surveillance, Epidemiology, and End Results–Medicare records from 2001 to 2005 for 26 163 women aged 66 years or older with nonmetastatic breast cancer treated with surgery and radiotherapy. The impact of individual covariates (demographic, health services, tumor, and treatment factors) on cost of treatment was assessed using the Wilcoxon two-sample test. Two-sided multivariable logistic regression was used to identify predictors for IMRT use. Cost of radiation was calculated in 2005 dollars. All statistical tests were two-sided.
Results The number of patients with IMRT billing claims increased from 0.9% (49 of 5196) of patients diagnosed in 2001 to 11.2% (564 of 5020) in 2005. In multivariable analysis, IMRT billing was more likely for patients with left-sided tumors (odds ratio [OR] = 1.30, 95% confidence interval [CI] = 1.16 to 1.45), for those residing in a health service area with high radiation oncologist density (OR = 2.32, 95% CI = 1.47 to 3.68), for those treated at freestanding radiation centers (OR = 1.36, 95% CI = 1.20 to 1.53), or for those residing in regions where the Medicare intermediary allowed breast IMRT (OR = 10.87, 95% CI = 9.26 to 12.76, all P < .001). The mean cost of radiation was $7179 without IMRT and $15 230 with IMRT. IMRT adoption contributed to an increase in the mean cost of breast radiation from $6334 in 2001 to $8473 in 2005.
Conclusions IMRT billing increased 10-fold from 2001 through 2005, contributing to a 33% increase in the cost of breast radiation. These findings suggest that reimbursement policy and practice setting strongly influenced adoption of IMRT billing for breast cancer.
Introduction
Breast cancer is the most common cancer treated with radiation therapy in the United States, with approximately 120 000 women treated annually. For women with breast cancer, multiple high-quality randomized trials have demonstrated that radiation therapy plays an important role in enabling breast conservation, optimizing local-regional control, and improving survival. Although generally well tolerated, radiotherapy to the breast or chest wall may be associated with acute toxic effects such as dermatitis and late toxic effects such as soft tissue fibrosis and cardiovascular sequelae. The historic limitations of conventional radiotherapy delivered with two-dimensional planning may have contributed to the severity of these toxic effects. Specific limitations of two-dimensional radiotherapy include the inability to accurately calculate volumetric dose distributions and to account for dose inhomogeneity in off-axis planes and reliance on static wedge compensators of fixed dimensions, which often do not optimally account for irregular tissue separations.
To reduce the risk of radiation toxicity, three-dimensional treatment planning and dynamic multileaf collimators have been used to modulate the radiotherapy dose in three dimensions across the breast and chest wall, thereby improving the homogeneity of the dose deposited. A growing body of evidence now suggests that such three-dimensional modulation of the radiation beam profile improves dose homogeneity within the treated breast and lowers dose to the contralateral breast and, potentially, the heart. In addition, recently published randomized trials have demonstrated that this dosimetric gain translates into a lower risk of acute skin toxicity and improved long-term cosmetic outcome for patients receiving whole-breast irradiation following conservative surgery.
These clinically beneficial techniques that involve three-dimensional modulation of the radiation beam profile can be achieved using intensity-modulated radiation therapy (IMRT) or with other techniques that do not require IMRT. Prior research has indicated that treatment with IMRT is associated with increased cost, but to date, it is not known to what extent IMRT is used in the treatment of breast cancer and what factors may have affected its adoption. Identifying factors that promote the use of a more costly therapy is critically important, given the imperative to promote cost-effective value-oriented practice in today's health-care environment. Accordingly, we used population-based data to characterize adoption of IMRT billing for patients diagnosed with breast cancer between 2001 and 2005, to identify demographic, health services, tumor, and treatment factors associated with the use of IMRT billing, and to compare the cost of care between radiation therapy with and without IMRT billing.