Hypofractionated Prostate Radiation Therapy: Adoption and Dosimetric Adherence Through Clinical Pathways in an Integrated Oncology Network.

Abstract

Updates to consensus guidelines in October 2018 recommending moderately hypofractionated external beam radiotherapy (mHF-EBRT) in prostate cancer lagged several years after publication of evidence supporting its efficacy. In January 2018, we amended our prostate cancer clinical pathway (CP) to facilitate adoption of mHF-EBRT. Herein, we analyze patterns of care and changes in mHF-EBRT use after the CP modification. Our prostate CP was amended in January 2018 to make mHF-EBRT the recommended treatment for patients with low- and intermediate-risk prostate cancer pursuing curative EBRT monotherapy. Normal-tissue dose constraints accompanied the CP modification to guide planning. Use of mHF-EBRT from 2015 to 2017 was compared with use in 2018 after the CP modification, using the Cochran-Armitage test for trend. Predictors of mHF-EBRT use and adherence to dose constraints were analyzed with binary logistic regression. In 560 patients treated with EBRT monotherapy, mHF-EBRT use increased from 3.7% in 2015-2017 to 85.6% in 2018 (<i>P</i> < .001), whereas conventionally fractionated EBRT (CF-EBRT) use decreased from 96.3% to 14.4% (<i>P</i> < .001). Consultation year of 2018 (odds ratio [OR], 214.6; 95% CI, 94.5 to 484.6; <i>P</i> < .001), treatment at an academic facility (OR, 4.5; 95% CI, 1.8 to 11.3; <i>P</i> = 0.001), and having a smaller prostate (OR, 0.99; 95% CI, 0.97 to 1.00; <i>P</i> = .028) predicted for mHF-EBRT use. At least five of six recommended bladder and rectal dose constraints were met in 89.4% of patients. Modification of our prostate cancer CP, in concert with institutional policies to monitor and audit CP compliance, facilitated rapid adoption of mHF-EBRT in our large, integrated cancer center with good adherence to dosimetric constraints.