Radiologist Involvement in Radiation Oncology Peer Review: A Systematic Review and Meta-Analysis.

Importance: Radiotherapy (RT) plan quality is an established predictive factor associated with cancer recurrence and survival outcomes. The addition of radiologists to the peer review (PR) process may increase RT plan quality. Objective: To determine the rate of changes to the RT plan with and without radiology involvement in PR of radiation targets. Data Sources: PubMed, Scopus, and Web of Science were queried for peer-reviewed articles published from inception up to March 6, 2024. Search terms included key words associated with PR of contoured targets for the purposes of RT planning with or without radiology involvement. Study Selection: Studies reporting PR of contoured radiation targets with or without radiology involvement. Studies were excluded if they lacked full text, reported clinical trial-specific quality assurance, or reported PR without dedicated review of RT targets. Data Extraction and Synthesis: Data were extracted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Titles and abstracts were screened by 2 reviewers. In the case of discordance, discussion was used to reach consensus regarding inclusion for full-text review. RT plan changes were characterized as major when the change was expected to have a substantial clinical impact, as defined by the original study. Pooled outcomes were estimated using random-effects models. Main Outcomes and Measures: Primary outcome was pooled rate of RT plan changes. Secondary outcomes included pooled rates of major and minor changes to RT targets or organs at risk. Results: Of 4185 screened studies, 31 reporting 39 509 RT plans were included (390 with radiology and 39 119 without). The pooled rate of plan changes was 29.0% (95% CI, 20.7%-37.2%). Radiologist participation in PR was associated with significant increases in plan change rates (49.4% [95% CI, 28.6%-70.1%] vs 25.0% [95% CI, 17.0%-33.1%]; P = .02) and in clinically relevant major changes (47.0% [95% CI, 34.1%-59.8%] vs 10.2% [95% CI, 4.6%-15.8%]; P < .001). There was no difference in minor changes (15.2% [95% CI, 9.7%-20.6%] vs 13.8% [95% CI, 9.3%-18.3%]; P = .74). Subgroup analyses identified increases in the rates of changes to the gross tumor and planning target volumes with radiology-based PR. The highest rates of plan changes were observed in head and neck or lung cancer studies, studies performing PR prior to RT planning, and prospective studies. Conclusions and Relevance: In this systematic review and meta-analysis of radiation oncology PR of contoured targets, radiologist involvement in peer review was associated with a significant increase in the rate of total and clinically meaningful changes to the RT targets with no change in minor change rates. These results support the value of interdisciplinary collaboration with radiology during RT planning.