Magnetic Resonance-based Response Assessment and Dose Adaptation in Human Papilloma Virus Positive Tumors of the Oropharynx treated with Radiotherapy (MR-ADAPTOR): An R-IDEAL stage 2a-2b/Bayesian phase II trial

• Published in: Clinical and translational radiation oncology 2018-11, Vol.13, p.19-23
• Main Authors: Bahig, Houda, Yuan, Ying, Mohamed, Abdallah S.R., Brock, Kristy K., Ng, Sweet Ping, Wang, Jihong, Ding, Yao, Hutcheson, Kate, McCulloch, Molly, Balter, Peter A., Lai, Stephen Y., Al-Mamgani, Abrahim, Sonke, Jan-Jakob, van der Heide, Uulke A., Nutting, Christopher, Li, X. Allen, Robbins, Jared, Awan, Mussadiq, Karam, Irene, Newbold, Katherine, Harrington, Kevin, Oelfke, Uwe, Bhide, Shreerang, Philippens, Marielle E.P., Terhaard, Chris H.J., McPartlin, Andrew J., Blanchard, Pierre, Garden, Adam S., Rosenthal, David I., Gunn, Gary B., Phan, Jack, Cazoulat, Guillaume, Aristophanous, Michalis, McSpadden, Kelli K., Garcia, John A., van den Berg, Cornelis A.T., Raaijmakers, Cornelis P.J., Kerkmeijer, Linda, Doornaert, Patricia, Blinde, Sanne, Frank, Steven J., Fuller, Clifton D.
• Format: Article
• Language: English
• Subjects: Adaptive radiotherapy; Human papilloma virus; Magnetic resonance imaging guided radiotherapy; Oropharyngeal cancer
• ISSN: 2405-6308; 2405-6308
• DOI: 10.1016/j.ctro.2018.08.003

•Treatment de-escalation in HPV+ oropharynx cancer is an active area of research.•A Bayesian phase II trial of MR-guided radiotherapy dose adaptation is proposed.•High dose volume will be adapted on weekly MRI based on tumor response.•The non-inferiority of dose adaptation compared to standard IMRT will be assessed. Current standard radiotherapy for oropharynx cancer (OPC) is associated with high rates of severe toxicities, shown to adversely impact patients’ quality of life. Given excellent outcomes of human papilloma virus (HPV)-associated OPC and long-term survival of these typically young patients, treatment de-intensification aimed at improving survivorship while maintaining excellent disease control is now a central concern. The recent implementation of magnetic resonance image – guided radiotherapy (MRgRT) systems allows for individual tumor response assessment during treatment and offers possibility of personalized dose-reduction. In this 2-stage Bayesian phase II study, we propose to examine weekly radiotherapy dose-adaptation based on magnetic resonance imaging (MRI) evaluated tumor response. Individual patient’s plan will be designed to optimize dose reduction to organs at risk and minimize locoregional failure probability based on serial MRI during RT. Our primary aim is to assess the non-inferiority of MRgRT dose adaptation for patients with low risk HPV-associated OPC compared to historical control, as measured by Bayesian posterior probability of locoregional control (LRC). Patients with T1-2 N0-2b (as per AJCC 7th Edition) HPV-positive OPC, with lymph node