Radiotherapy Quality Assurance for the Peace 1 Trial: An Individual Case Review Analysis

Abstract

Purpose Radiotherapy quality assurance (RTQA) is essential for ensuring adherence to trial protocols. This paper summarizes the individual case review (ICR) results from the PEACE-1 trial, a phase-III study investigates standard of care (androgen deprivation therapy with or without docetaxel) with or without local radiotherapy; and with or without abiraterone acetate plus prednisone in patients with metastatic hormone-sensitive prostate cancer (mHSPC).Materials and Methods Participating institutions submitted radiotherapy (RT) plans for central review, assessing protocol compliance in target volume and organs at risk (OARs) delineation, as well as dose specifications. ICRs were conducted either retrospectively (r-ICRs), after starting RT, or prospectively (p-ICRs), before RT initiation. Case reviews were categorized as acceptable per protocol, acceptable variation, or unacceptable variation based on delineation and dose and plan parameters.Results Out of 585 patients in the RT arms, 527 (90%) had r-ICRs, primarily using intensity-modulated radiotherapy (IMRT). Delineation review approved 417 (87%) r-ICRs and 44 (92%) p-ICRs. The main reasons for unacceptable delineation were erroneous clinical target volume (CTV) delineation. In dose and plan reviews, 399 (96%) r-ICRs cases and 46 (96%) p-ICRs were approved, with unacceptable cases primarily due to PTV dose distribution issues.Conclusion RTQA is crucial in prostate cancer trials, primarily for proper target volume delineation. It is recommended to omit r-ICRs due to resource demands and lack of impact on RTQA outcomes, using limited p-ICRs with early feedback for site deviations and reserving full p-ICRs for trails with new techniques or dose regimens.

Note:
Funding declaration: Janssen-Cilag, Ipsen, Sanofi, and the French Programme Hospitalier de Recherche Clinique. The funding entities had no role in the design of the study, in the collection, analysis, or interpretation of data, in the writing of the manuscript, or in the decision to submit the article for publication.

Conflict of Interests: The author & co-authors have no potential Conflict of Interest.

Ethical Approval: The initial protocol was reviewed and approved by the French Independent Ethics Committee of Ile de France VII and by local institutional review boards at each study site. This study was conducted in compliance with the ethical principles defined by the Declaration of Helsinki and conformed with the International Conference on Harmonization and Good Clinical Practice guidelines, as well as applicable regulatory requirements. Approval was obtained from the ethics committee of each participating centre and is available upon request.

Keywords: PEACE-1, prostate cancer, RTQA, Quality Assurance