Does Quality of Radiation Therapy Predict Outcomes of Multicenter Cooperative Group Trials? A Literature Review

Abstract

Central review of radiotherapy (RT) delivery within multicentre clinical trials was initiated in the early 1970’s in the USA. Early quality assurance (QA) publications often focused on metrics related to process, logistics and timing. Our objective was to review the available evidence supporting correlation of RT quality with clinical outcomes within cooperative group trials. Medline search was performed to identify multicentre studies which described central subjective assessment of RT protocol compliance (quality). Data abstracted included method of central review, definition of deviations, and clinical outcomes. Seventeen multicentre studies (1980–2012) were identified, plus one Patterns of Care Study. Disease sites were hematologic, head and neck, lung, breast and pancreas. Between 0% and 97% of treatment plans received an overall grade of acceptable. In seven trials, failure rates were significantly higher after inadequate versus adequate RT. 5/9 and 2/5 trials reported significantly worse overall and progression-free survival after poor quality RT, respectively. One reported a significant correlation and two reported non-significant trends towards increased toxicity with non-compliant RT. Although more data are required, protocol-compliant RT may decrease failure rates and increase overall survival and likely contributes to the ability of collected data to answer the central trial question.

Executive summary of AAPM Report Task Group 113: Guidance for the physics aspects of clinical trials

“…It has been shown that the quality and consistency of the trial impacts patient outcomes 1, 2, 3, 4, 5. This report identifies physics and other team member practices that specifically improve the treatment planning and delivery data for clinical trials.…”

“…The importance of compliance in trials and the impact on detecting changes in outcome have been demonstrated in a number of trials,1, 2, 3, 4, 6 such as TROG 02.02 on advanced head and neck cancer (Fig. 1), and in meta‐analyses of other trials.…”

“…There is growing evidence1, 2, 3, 4, 5 on the need for standardization of treatment planning and delivery methods to ensure quality in clinical trials to help support the investigation of new safe and effective treatments and/or assessment methods in multi‐institutional settings. Such standardization will improve the consistency of the radiotherapy received by patients and the radiotherapy data submitted for a given clinical trial.…”

Radiation Oncology Quality and Safety Considerations in Low-Resource Settings: A Medical Physics Perspective

“…A recent review 4 which specifically addressed the question "Does quality of radiotherapy predict outcomes of multicenter cooperative group trials?" found, through a thorough literature review, that in nearly half the trials, clinical failure rates were significantly higher after inadequate versus adequate RT and that significantly worse overall and progressionfree survival occurred after poor quality RT.…”

Radiotherapy for Prostate Cancer: is it ‘what you do’ or ‘the way that you do it’? A UK Perspective on Technique and Quality Assurance

“…The US, via the Radiation Therapy Oncology Group (RTOG), has, with central funding, had formal QA programmes since the 1970's for clinical trials employing radiotherapy with detailed credentialing for trial centres for IMRT trials [36]. Funding from RTOG has allowed on-trial review and analysis of trial outcomes against levels of protocol adherence which has historically been beyond our scope in the UK.…”