Dose-Volume Histogram Compendium of Dose Constraints for Treatment Planning: An ASTRO Consensus Paper

Abstract

Purpose: This dose-volume histogram (DVH) compendium shares the knowledge and resources compiled by disease-site experts during an immense undertaking by the Veterans Affairs (VA) and American Society for Radiation Oncology (ASTRO) to develop performance indicators for radiation therapy as part of quality surveillance. The guidance for breast, head and neck, liver, lung, prostate, and rectal cancers supports physician decision-making during dosimetric treatment planning, directs the reader to additional resources, and contributes to the evolution of DVH metrics for external beam radiation therapy.

Methods and materials: DVH tables were developed for each disease site relating to the most common dose/fractionation regimens used in VA and non-VA radiation oncology centers nationwide. Dosimetric values with validation through prior clinical data and those used in ongoing multisite trials were prioritized, with references listed in the tables. In scenarios with a paucity of data for specific constraints, the disease-site panels discussed and agreed on appropriate clinical guidance. After panel discussion, each metric was voted on to obtain panel consensus. Panel consensus was evaluated with a modified Delphi approach using a prespecified threshold of ≥75% of raters who agree or strongly agree to establish consensus via a confidential survey. Where the content did not meet this threshold, it was removed or revised. Significant revisions went back to the full disease-site panel for review, approval, and a final consensus vote.

Results: The dose constraints are the result of quality measure development between the VA and ASTRO. They represent the body of work thus far, with the goal of expanding future resources to include other disease sites. There is still work to be done to optimize dose goals and constraints for target volumes and normal tissues. Different methodologies for calculating doses have produced varying data, and ongoing efforts will harmonize the lack of concordance where possible. Wide variation when reporting on toxicities and efforts to standardize provide an opportunity for future trial data to add to the depth of knowledge. This DVH compendium is pragmatic and reflective of general practice and established treatment regimens. Having accessible default constraints supports standardization and will help improve the quality of treatment planning and radiation delivery for all patients.