1081 - Systematic Review of Quality Assurance Metrics Used to Standardize Target and Organ at Risk Contours on Cooperative Group Clinical Trials

L. Tchelebi¹, J. Lester¹, H. Geng², and Y. Xiao²; ¹Northwell, Lake Success, NY, ²Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA

Purpose/Objective(s): Quality assurance (QA) is critical to the success of radiation therapy (RT) for cancer patients and impacts trial outcomes. Rigorous RT QA has, therefore become a required component of cooperative group trials. While evaluation of radiation contours and plans is mandatory, there is no standardized quantitative method of evaluating RT plans, specifically with respect to target and organ at risk (OAR) contours. We aimed to evaluate the existence of standardized quantitative metrics used in grading contours as part of the RT QA process. Materials/

Methods: A systematic review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses. Pubmed and Embase were used to search relevant studies published in the last 15 years involving quality assurance analyses of target volume and OAR contours on randomized clinical trials conducted by cooperative groups in the United States or abroad. Our study endpoints were quantitative metrics being used to guide QA scoring.
Results: Our search yielded a total of 413 studies which were independently screened by two authors. A total of 46 studies were included in the final analysis. Eleven studies involved QA for CNS trials, eight gastrointestinal, seven lung, seven prostate, four breast, four head and neck, one lymphoma, one sarcoma, and three for multiple disease sites. Twenty-six studies involved a retrospective analysis of contours done on clinical trials involving either benchmark cases or dummy runs as part of the trials’ QA program. Eleven studies involved prospective evaluation of new contours generated for patients already treated on trial or by members of cooperative groups as a means of evaluating variability in contouring of the same targets or OARs. Six studies were contouring guidelines created by experts from cooperative groups to assist with target volume or OAR delineation, and 3 studies involved either the creation of objective scoring metrics or automated systems to generate or evaluate contours.
Conclusion: There is a concerning lack of standardized quantitative metrics used to evaluate RT target and OAR contours which can negatively impact clinical trial results. Effort is needed to create guidelines for objectively evaluating RT contours to be used across clinical trials to improve the quality and validity of RT QA.