Is Prostate Brachytherapy a Dying Art? Evidence of Increasing Utilization in Ontario, Canada

Abstract

A worldwide decline in prostate brachytherapy (BT) utilization has been reported in multiple health care settings/jurisdictions, despite strong evidence for efficacy and safety compared to other alternatives. We sought to evaluate contemporary trends in BT, EBRT and prostatectomy utilization in a publicly funded healthcare system. Men with localized prostate cancer diagnosed and treated between 2007 and 2017 in Ontario, Canada were identified using administrative data from the Institute for Clinical Evaluative Sciences. Men were coded to have received EBRT, BT (monotherapy or boost) or prostatectomy as initial definitive management. Trends were evaluated using the Cochran-Armitage test. Multivariate logistic regression was used to evaluate patient-, tumor-, and provider-factors on treatment utilization over time. There were 57,655 men were included in our study. Prostate BT use increased from 7.5% of all treatments in 2007 to 15.4% in 2017 (p<0.01), primarily due to increased use of BT boost (1.7% in 2007 to 10.4% in 2017, p<0.01). Relative to EBRT, BT use increased from 17.9% in 2007 to 28.1% in 2017 (p<0.01). On multivariate analysis (MVA), BT boost use increased by 28% per year (OR 1.28, 95% CI 1.26–1.31, p<0.01) and BT monotherapy use increased by 12% per year (OR 1.12, 95% CI 1.10–1.14, p<0.01), offset by decreasing prostatectomy use (12% per year, OR 0.88, 95% CI 0.87–0.89, p<0.01). Comparing BT to EBRT, the strongest predictors of receiving BT were geographic residence (OR 27.6, 95% CI: 20.3–37.6, p<0.01 between highest/lowest Local Health Integration Networks) and whether the first consulting radiation oncologist performed BT (OR 3.46, 95% CI: 3.15–3.80, p<0.01). Other significant factors predicting BT use vs. EBRT included lower age, lower PSA, lower Charlson comorbidity score and increasing neighborhood income quintile. Low-intermediate, high-intermediate and high-risk groups were predictive of receiving BT boost, whereas BT monotherapy was predominantly used in low-risk disease. Contrary to trends observed in other jurisdictions, utilization of prostate BT is increasing over time in Ontario. However, substantial variation in BT utilization was found, strongly driven by both geographic region and radiation oncologist BT practice patterns. To our knowledge, this is the first study to report increasing BT utilization in the era of dose-escalated EBRT, with Ontario potentially serving as a model to promote BT utilization elsewhere.