A decade of prospective peer review: impact on safety culture and lessons learned in a multicenter radiation medicine department.

PURPOSE: Quality assurance (QA) is critical to the success of radiation therapy (RT) for cancer patients and impacts clinical outcomes. We report longitudinal findings of a prospective peer review evaluation system (PES) implemented at a major academic health system as part of RT QA over a ten-year period.

MATERIALS/METHODS: All cases treated within our department undergo prospective multi-disciplinary peer review and are assigned a grade (A, B, C). "A" cases require no changes, "Bs" require minor modification, and "Cs" require major modification, prior to treatment planning. The z-ratio test for the significance of the difference between the 5-year baseline (2012-2016) and follow-up (2017-2021) period was used to compare grades between the two periods. A 2-tailed p-value below 0.05 is considered significant.

RESULTS: Of the 20,069 cases, 15,659 (78%) were curative and were analyzed.  The fraction of A's decreased from 74.8% (baseline), to 64.5% (follow-up), while B's increased from 19.4% to 35.4%, and C's decreased from 5.8% to 0.1%. Of the 9 treatment locations, the main hospital site had a higher percentage of A grades relative to community locations in the baseline, (78.6% versus 67.8%, p<0.002), and follow-up, (66.9% versus 62.3%, p<0.002) periods. There was a decrease in the percentage of A's from the baseline to the follow-up period regardless of plan type (complex versus intermediate versus simple). There was a decrease in percentage of A's among specialists from baseline to follow-up (78.2% to 67.7%, p<0.002) and among generalists from baseline to follow-up (69.7% to 61.7%, p<0.002).

CONCLUSIONS: Our ten-year experience in contour peer review identified increased opportunities in improving treatment plan quality over time. The drop in A scores /rise in B score suggests increased scrutiny and findings-based improvements over time, while the drop in C scores indicates amelioration of 'major failures' addressed in the startup years. Peer review rounds upstream of treatment planning provides valuable RT QA and should be considered by other departments to enhance the quality and consistency of RT.