Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Multicenter Study
. 2023 Oct;48(10):3039-3049.
doi: 10.1007/s00261-023-03961-7. Epub 2023 Jun 26.

Predicting response to chemoradiotherapy in rectal cancer via visual morphologic assessment and staging on baseline MRI: a multicenter and multireader study

Najim El Khababi  1   2 , Regina G H Beets-Tan  1   2 , Renaud Tissier  3 , Max J Lahaye  1   2 , Monique Maas  1   2 , Luís Curvo-Semedo  4 , Raphaëla C Dresen  5 , Stephanie Nougaret  6 , Geerard L Beets  2   7 , Doenja M J Lambregts  8   9 ; rectal MRI study group
Collaborators, Affiliations
Multicenter Study

Predicting response to chemoradiotherapy in rectal cancer via visual morphologic assessment and staging on baseline MRI: a multicenter and multireader study

Najim El Khababi et al. Abdom Radiol (NY). 2023 Oct.

Abstract

Purpose: Pre-treatment knowledge of the anticipated response of rectal tumors to neoadjuvant chemoradiotherapy (CRT) could help to further optimize the treatment. Van Griethuysen et al. proposed a visual 5-point confidence score to predict the likelihood of response on baseline MRI. Aim was to evaluate this score in a multicenter and multireader study setting and compare it to two simplified (4-point and 2-point) adaptations in terms of diagnostic performance, interobserver agreement (IOA), and reader preference.

Methods: Twenty-two radiologists from 14 countries (5 MRI-experts,17 general/abdominal radiologists) retrospectively reviewed 90 baseline MRIs to estimate if patients would likely achieve a (near-)complete response (nCR); first using the 5-point score by van Griethuysen (1=highly unlikely to 5=highly likely to achieve nCR), second using a 4-point adaptation (with 1-point each for high-risk T-stage, obvious mesorectal fascia invasion, nodal involvement, and extramural vascular invasion), and third using a 2-point score (unlikely/likely to achieve nCR). Diagnostic performance was calculated using ROC curves and IOA using Krippendorf's alpha (α).

Results: Areas under the ROC curve to predict the likelihood of a nCR were similar for the three methods (0.71-0.74). IOA was higher for the 5- and 4-point scores (α=0.55 and 0.57 versus 0.46 for the 2-point score) with best results for the MRI-experts (α=0.64-0.65). Most readers (55%) favored the 4-point score.

Conclusions: Visual morphologic assessment and staging methods can predict neoadjuvant treatment response with moderate-good performance. Compared to a previously published confidence-based scoring system, study readers preferred a simplified 4-point risk score based on high-risk T-stage, MRF involvement, nodal involvement, and EMVI.

Keywords: Chemoradiotherapy; Magnetic resonance imaging; Rectal cancer; Response.

PubMed Disclaimer

Conflict of interest statement

The authors have nothing to declare.

Figures

Fig. 1
Fig. 1
Instructions provided to the study readers to assign a 4-point risk score based on the presence/absence of 4 key high-risk features: obvious MRF invasion, high-risk T-stage (bulky/irregular, T3c-4), obvious node-positive disease, and obvious EMVI. Readers were instructed to only select yes if they were confident that a respective worrisome feature was present. When in doubt, readers were instructed to select ‘no’
Fig. 2
Fig. 2
Instructions provided to study readers to assign a dichotomized (2-point) risk score. Green = low risk, i.e., tumor likely to achieve a (near-)complete response. Red = high risk, i.e., tumor unlikely to achieve a (near-)complete response
See this image and copyright information in PMC

References

    1. Oronsky B, Reid T, Larson C, Knox SJ. Locally advanced rectal cancer: The past, present, and future. Semin Oncol. 2020;47(1):85–92. doi: 10.1053/j.seminoncol.2020.02.001. - DOI - PubMed
    1. Fernandes MC, Gollub MJ, Brown G (2022) The importance of MRI for rectal cancer evaluation. Surg Oncol 43:101739. 10.1016/j.suronc.2022.101739 - PMC - PubMed
    1. van der Valk MJM, Hilling DE, Bastiaannet E, et al. Long-term outcomes of clinical complete responders after neoadjuvant treatment for rectal cancer in the International Watch & Wait Database (IWWD): an international multicentre registry study. Lancet. 2018;391(10139):2537–2545. doi: 10.1016/S0140-6736(18)31078-X. - DOI - PubMed
    1. Bach SP, STAR-TREC Collaborative Can we Save the rectum by watchful waiting or TransAnal surgery following (chemo)Radiotherapy versus Total mesorectal excision for early REctal Cancer (STAR-TREC)? Protocol for the international, multicentre, rolling phase II/III partially randomized patient preference trial evaluating long-course concurrent chemoradiotherapy versus short-course radiotherapy organ preservation approaches. Colorectal Dis. 2022;24(5):639–651. doi: 10.1111/codi.16056. - DOI - PMC - PubMed
    1. Schurink NW, Lambregts DMJ, Beets-Tan RGH. Diffusion-weighted imaging in rectal cancer: current applications and future perspectives. Br J Radiol. 2019;92(1096):20180655. doi: 10.1259/BJR.20180655. - DOI - PMC - PubMed

Publication types