MRI restaging of rectal cancer: The RAC (Response–Anal canal–CRM) analysis joint consensus guidelines of the GRERCAR and GRECCAR groups

• Published in: Diagnostic and interventional imaging Vol. 104; no. 7-8; pp. 311 - 322
• Main Authors: Nougaret, Stephanie, Rousset, Pascal, Lambregts, Doenja M.J., Maas, Monique, Gormly, Kirsten, Lucidarme, Oliver, Brunelle, Serge, Milot, Laurent, Arrivé, Lionel, Salut, Celine, Pilleul, Franck, Hordonneau, Constance, Baudin, Guillaume, Soyer, Philippe, Brun, Vanessa, Laurent, Valérie, Savoye-Collet, Celine, Petkovska, Iva, Gerard, Jean-Pierre, Cotte, Eddy, Rouanet, Philippe, Catalano, Onofrio, Denost, Quentin, Tan, Regina Beets, Frulio, Nora, Hoeffel, Christine
• Format: Journal Article
• Language: English
• Published: France Elsevier Masson SAS 01.07.2023; Elsevier
• Subjects: Computer Science; Magnetic resonance imaging; Medical Imaging; Neoadjuvant therapy; Re-staging; Rectal neoplasms; Watch-and-wait; Re-staging; ADC; ECRT; MRF; NAT; Neoadjuvant therapy; Watch-and-wait; GRECCAR group; GRERCAR group; LARC; MRI; Rectal neoplasms; FOV; TME; mrTRG; TNM; Magnetic resonance imaging; DWI; T2W; ESGAR; EMVI; CRM
• ISSN: 2211-5684; 2211-5684
• DOI: 10.1016/j.diii.2023.02.002

•The evaluation of tumor response in rectal cancer is a challenge for the radiologist.•The main features to evaluate can be summarized through the “RAC assessment: Response–Anal canal– Circumferential resection margin”.•The combination of functional and morphological tumor features on MRI helps assess rectal tumor response to neoadjuvant therapy.•After a near complete tumor response on MRI, another MRI evaluation at six to ten weeks is recommended to potentially propose a watch and wait approach. To develop guidelines by international experts to standardize data acquisition, image interpretation, and reporting in rectal cancer restaging with magnetic resonance imaging (MRI). Evidence-based data and experts’ opinions were combined using the RAND-UCLA Appropriateness Method to attain consensus guidelines. Experts provided recommendations for reporting template and protocol for data acquisition were collected; responses were analysed and classified as “RECOMMENDED” versus “NOT RECOMMENDED” (if ≥ 80% consensus among experts) or uncertain (if < 80% consensus among experts). Consensus regarding patient preparation, MRI sequences, staging and reporting was attained using the RAND-UCLA Appropriateness Method. A consensus was reached for each reporting template item among the experts. Tailored MRI protocol and standardized report were proposed. These consensus recommendations should be used as a guide for rectal cancer restaging with MRI.