In a study reported in JCO Oncology Practice, Schad et al found that modifying the prostate cancer clinical pathway in an integrated oncology network to designate moderately hypofractionated external-beam radiotherapy (mHF-EBRT) as the recommended curative EBRT monotherapy in low- and intermediate-risk prostate cancer resulted in rapid uptake of the modality within 1 year.
The investigators stated, “Updates to consensus guidelines in October 2018 recommending 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 to facilitate adoption of mHF-EBRT.”
Study Details
The study involved data from 560 patients treated with EBRT monotherapy between 2015 and 2018 in the UPMC Hillman Cancer Center network. The clinical pathway was modified on January 31, 2018, to list mHF-EBRT as the preferred treatment option. Prior to this, it was listed as a treatment option but not specified as the preferred option. After the alteration, physicians choosing to use conventionally fractionated EBRT (CF-EBRT) had to communicate their rationale to pathway directors.
According to the clinical pathway, mHF-EBRT consisted of 70 Gy in 28 fractions or 60 Gy in 20 fractions via intensity-modulated radiation therapy. Recommended normal tissue dose constraints were volume receiving 70 Gy (V70) < 10 cc, V65 < 15%, and V40 < 35% for the bladder and V70 < 10 cc, V65 < 10%, and V40 < 35% for the rectum.
Key Findings
Among the 560 patients receiving EBRT monotherapy, 437 patients received CF-EBRT and 123 received mHF-EBRT over the study period. All patients receiving mHF-EBRT received 70 Gy in 28 fractions (none received 60 Gy in 20 fractions).
Use of mHF-EBRT increased from 3.7% in 2015–2017 to 85.6% in 2018 (P < .001), whereas use of CF-EBRT decreased from 96.3% to 14.4% (P < .001).
On multivariate analysis, factors significantly associated with use of mHF-EBRT were consultation year being 2018 (odds ratio [OR] = 214.6, P < .001), treatment at an academic facility vs community center (OR = 4.5, P = .001), and smaller prostate as continuous variable (OR = 0.99, P = .028).
Among patients receiving mHF-EBRT, all six recommended bladder and rectal normal tissue dose constraints were met in 61.8% of patients and at least five were met in 89.4%. Adherence to bladder V70, V65, and V40 dose constraints occurred in 82.1%, 98.4%, and 91.1% of patients; all three constraints were met in 74.0% and at least two were met in 98.4%. Adherence to rectal V70, V65, and V40 dose constraints occurred in 99.2%, 87.8%, and 85.6% of patients; all three constraints were met in 81.3% and at least two in 91.9%.
The investigators concluded, “Modification of our prostate cancer clinical pathway, in concert with institutional policies to monitor and audit clinical pathway compliance, facilitated rapid adoption of mHF-EBRT in our large, integrated cancer center with good adherence to dosimetric constraints.”
Sushil Beriwal, MD, MBA, of UPMC Hillman Cancer Center, Department of Radiation Oncology, University of Pittsburgh School of Medicine, is the corresponding author for the JCO Oncology Practice article.
Disclosure: The study was supported by a grant from the Shadyside Hospital Foundation. For full disclosures of the study authors, visit ascopubs.org.
