National variation in the delivery of radiation oncology procedures in the non-facility-based setting.

PURPOSE: Though utilization of medical procedures has been shown to vary considerably across the United States, similar efforts to characterize variation in the delivery of radiation therapy (RT) procedures have not been forthcoming. Our aim was to characterize variation in the delivery of common RT procedures in the Medicare population. We hypothesized that delivery would vary significantly based on provider characteristics. METHODS: The Centers for Medicare and Medicaid Services (CMS) Physician and Other Supplier Public Use File was linked to the CMS Physician Compare (PC) database by physician NPI to identify and sum all treatment delivery charges submitted by individual radiation oncologists in the non-facility-based (NFB) setting in 2016. Multivariable logistic regression analysis was carried out to determine provider characteristics (gender, practice rurality, practice region, and years since graduation) that predicted for the delivery of 3D conformal RT (3DCRT), intensity modulated RT (IMRT), stereotactic body RT (SBRT), stereotactic radiosurgery (SRS), low dose rate (LDR) brachytherapy, and high dose rate (HDR) brachytherapy delivery in the Medicare patient population. The overall significance of categorical variables in the multivariable logistic regression model was assessed by the likelihood ratio test (LRT). RESULTS: In total, 1,802 physicians from the NFB practice setting were analyzed. Male gender predicted for greater LDR brachytherapy delivery (OR 8.19, 95% CI 2.58-26.05, p < 0.001), but not greater delivery of other technologies. Metropolitan practice was the only predictor for greater HDR brachytherapy utilization (OR 12.95, 95% CI 1.81-92.60, p = 0.01). Practice region was predictive of the delivery of 3DCRT, SRS and SBRT (p < 0.01, p < 0.001, and p < 0.001, respectively). With the Northeast as the reference region, 3DCRT was more likely to be delivered by providers in the South (OR 1.33, 95% CI 1.09-1.62, p < 0.01) and the West (OR 1.38, 95% CI 1.11-1.71, p < 0.01). At the same time, SRS use was less likely in the Midwest (OR 0.71, 95% CI 0.55-0.91, p < 0.01), South (OR 0.49, 95% CI 0.40-0.61, p < 0.001), and West (OR 0.43, 95% CI 0.34-0.55, p < 0.001). SBRT, on the other hand, was more commonly utilized in the Midwest (OR 2.63, 95% CI 1.13-6.13, p = 0.03), South (OR 3.44, 95% CI 1.58-7.49, p < 0.01), and West (OR 4.87, 95% CI 2.21-10.72, p < 0.001). HDR brachytherapy use was also more likely in the Midwest (OR 1.97, 95% CI 1.11-3.49, p = 0.02) and West (OR 1.87, 95% CI 1.08-3.24, p = 0.03). While the degree held by the billing physician did not predict for delivery of a given procedure, greater years since graduation was related to decreased likelihood of SBRT use (OR 0.98, 95% CI 0.96-0.99, p < 0.001) and increased likelihood of LDR brachytherapy use (OR 1.02, 95% CI 1.00-1.04, p = 0.02). CONCLUSIONS: Substantial geographic variation in the use of specific RT technologies was identified. The degree to which this variation reflects effective care, preference-sensitive care, or supply-sensitive care warrants further investigation.

Provider-Level Variation in Treatment Planning of Radiation Oncology Procedures in the United States.

PURPOSE: Variation in the use of radiation oncology procedures and technologies is poorly characterized. We sought to identify associations between the treatment planning codes used to bill for radiotherapy procedures and the demographic characteristics of the radiation oncologists submitting them. METHODS: The Physician and Other Supplier Public Use File was linked to the Physician Compare database by using the physician National Provider Identifier for the year 2016. Analysis was stratified by practice setting, considering both the freestanding non-facility-based (NFB) setting and the facility-based (FB) setting. Multivariable logistic regression was used to determine provider characteristics (gender, practice rurality, and years since graduation) that predicted for the use of 3D-conformal RT (3DCRT) planning, intensity-modulated RT (IMRT) planning, and brachytherapy planning in the Medicare population. RESULTS: Three thousand twenty-nine physicians were linked for analysis. In both the FB and NFB settings together, male gender predicted for decreased likelihood of 3DCRT planning (OR, 0.70, 95% CI, 0.62 to 0.80, P < .001) and increased likelihood of IMRT planning (OR, 1.35, 95% CI, 1.19 to 1.54, P < .001). Brachytherapy planning was also more likely with increasing years since medical school graduation (OR, 1.03, 95% CI, 1.01 to 1.04, P < .001) in the combined FB and NFB settings. These significant associations persisted when examining the NFB and FB settings individually. In both settings overall, brachytherapy planning was more likely in male providers (OR, 1.75, 95% CI, 1.10 to 2.76, P = .02) and also more likely for providers practicing in metropolitan regions compared with those practicing in rural areas (OR, 3.01, 95% CI, 1.23 to 7.39, P = .02). CONCLUSION: Male gender predicts for utilization of IMRT planning, whereas female gender predicts for utilization of 3DCRT planning. Future research is warranted to better understand the role that provider gender and rurality play in the selection of radiation planning techniques for Medicare patients.

Time-Driven Activity-Based Costing Comparison of CT-Guided Versus MR-Guided SBRT.

PURPOSE: Magnetic resonance-guided radiation therapy (MRgRT) has recently become commercially available, offering the opportunity to accurately image and target moving tumors as compared with computed tomography-guided radiation therapy (CTgRT) systems. However, the costs of delivering care with these 2 modalities remain poorly described. With localized unresectable hepatocellular carcinoma as an example, we were able to use time-driven activity-based costing to determine the cost of treatment on linear accelerators with CTgRT compared with MRgRT. MATERIALS AND METHODS: Process maps, informed via interviews with departmental personnel, were created for each phase of the care cycle. Stereotactic body radiation therapy was delivered at 50 Gy in 5 fractions, either with CTgRT using fiducial placement, deep inspiration breath-hold (DIBH) with real-time position management, and volumetric-modulated arc therapy, or with MRgRT using real-time tumor gating, DIBH, and static-gantry intensity-modulated radiation therapy. RESULTS: Direct clinical costs were $7,306 for CTgRT and $8,622 for MRgRT comprising personnel costs ($3,752 v $3,603), space and equipment costs ($2,912 v $4,769), and materials costs ($642 v $250). Increased MRgRT costs may be mitigated by forgoing CT simulation ($322 saved) or shortening treatment to 3 fractions ($1,815 saved). Conversely, adaptive treatment with MRgRT would result in an increase in cost of $529 per adaptive treatment. CONCLUSION: MRgRT offers real-time image guidance, avoidance of fiducial placement, and ability to use adaptive treatments; however, it is 18% more expensive than CTgRT under baseline assumptions. Future studies that elucidate the magnitude of potential clinical benefits of MRgRT are warranted to clarify the value of using this technology.