Redesigning radiotherapy quality assurance: opportunities to develop an efficient, evidence-based system to support clinical trials--report of the National Cancer Institute Work Group on Radiotherapy Quality Assurance.

PURPOSE: In the context of national calls for reorganizing cancer clinical trials, the National Cancer Institute sponsored a 2-day workshop to examine challenges and opportunities for optimizing radiotherapy quality assurance (QA) in clinical trial design. METHODS AND MATERIALS: Participants reviewed the current processes of clinical trial QA and noted the QA challenges presented by advanced technologies. The lessons learned from the radiotherapy QA programs of recent trials were discussed in detail. Four potential opportunities for optimizing radiotherapy QA were explored, including the use of normal tissue toxicity and tumor control metrics, biomarkers of radiation toxicity, new radiotherapy modalities such as proton beam therapy, and the international harmonization of clinical trial QA. RESULTS: Four recommendations were made: (1) to develop a tiered (and more efficient) system for radiotherapy QA and tailor the intensity of QA to the clinical trial objectives (tiers include general credentialing, trial-specific credentialing, and individual case review); (2) to establish a case QA repository; (3) to develop an evidence base for clinical trial QA and introduce innovative prospective trial designs to evaluate radiotherapy QA in clinical trials; and (4) to explore the feasibility of consolidating clinical trial QA in the United States. CONCLUSION: Radiotherapy QA can affect clinical trial accrual, cost, outcomes, and generalizability. To achieve maximum benefit, QA programs must become more efficient and evidence-based.

The lessons of QUANTEC: recommendations for reporting and gathering data on dose-volume dependencies of treatment outcome.

The 16 clinical articles in this issue review the dose-volume dependence of toxicities of external beam radiotherapy. They are limited by the difficulty of synthesizing results from different publications. The major problems stem from incomplete reporting of results and use of incompatible or ambiguous endpoints. Here we specify these problems; give recommendations to authors, editors, and reviewers on standards of reporting; and provide methods of defining endpoints suitable for the dose-volume analysis of toxicity. Adopting these recommendations will facilitate meta-analysis and increase the utility of individual studies of the dependence of complications on dose distributions.