TY - JOUR
T1 - Selection of Patients for Organ Preservation After Chemoradiotherapy
T2 - MRI Identifies Poor Responders Who Can Go Straight to Surgery
AU - Haak, Hester E.
AU - Maas, Monique
AU - Lahaye, Max J.
AU - Boellaard, Thierry N.
AU - Delli Pizzi, Andrea
AU - Mihl, Casper
AU - van der Zee, Dennis
AU - Fabris, Cristina
AU - van der Sande, Marit E.
AU - Melenhorst, Jarno
AU - Beets-Tan, Regina G. H.
AU - Beets, Geerard L.
AU - Lambregts, Doenja M. J.
N1 - Publisher Copyright:
© 2020, Society of Surgical Oncology.
PY - 2020/8
Y1 - 2020/8
N2 - Objective The aim of this study was to evaluate whether magnetic resonance imaging (MRI) can accurately identify poor responders after chemoradiotherapy (CRT) who will need to go straight to surgery, and to evaluate whether results are reproducible among radiologists with different levels of expertise. Methods Seven independent readers with different levels of expertise retrospectively evaluated the restaging MRIs (T2-weighted + diffusion-weighted imaging [T2W + DWI]) of 62 patients and categorized them as (1) poor responders - highly suspicious of tumor; (2) intermediate responders - tumor most likely; and (3) good - potential (near) complete responders. The reference standard was histopathology after surgery (or long-term follow-up in the case of a watch-and-wait program). Results Fourteen patients were complete responders and 48 had residual tumor. The median percentage of patients categorized by the seven readers as 'poor', 'intermediate', and 'good' responders was 21% (range 11-37%), 50% (range 23-58%), and 29% (range 23-42%), respectively. The vast majority of poor responders had histopathologically confirmed residual tumor (73% ypT3-4), with a low rate (0-5%) of 'missed complete responders'. Of the 14 confirmed complete responders, a median percentage of 71% were categorized in the MR-good response group and 29% were categorized in the MR-intermediate response group. Conclusions Radiologists of varying experience levels should be able to use MRI to identify the +/- 20% subgroup of poor responders who will definitely require surgical resection after CRT. This may facilitate more selective use of endoscopy, particularly in general settings or in centers with limited access to endoscopy.
AB - Objective The aim of this study was to evaluate whether magnetic resonance imaging (MRI) can accurately identify poor responders after chemoradiotherapy (CRT) who will need to go straight to surgery, and to evaluate whether results are reproducible among radiologists with different levels of expertise. Methods Seven independent readers with different levels of expertise retrospectively evaluated the restaging MRIs (T2-weighted + diffusion-weighted imaging [T2W + DWI]) of 62 patients and categorized them as (1) poor responders - highly suspicious of tumor; (2) intermediate responders - tumor most likely; and (3) good - potential (near) complete responders. The reference standard was histopathology after surgery (or long-term follow-up in the case of a watch-and-wait program). Results Fourteen patients were complete responders and 48 had residual tumor. The median percentage of patients categorized by the seven readers as 'poor', 'intermediate', and 'good' responders was 21% (range 11-37%), 50% (range 23-58%), and 29% (range 23-42%), respectively. The vast majority of poor responders had histopathologically confirmed residual tumor (73% ypT3-4), with a low rate (0-5%) of 'missed complete responders'. Of the 14 confirmed complete responders, a median percentage of 71% were categorized in the MR-good response group and 29% were categorized in the MR-intermediate response group. Conclusions Radiologists of varying experience levels should be able to use MRI to identify the +/- 20% subgroup of poor responders who will definitely require surgical resection after CRT. This may facilitate more selective use of endoscopy, particularly in general settings or in centers with limited access to endoscopy.
KW - ADVANCED RECTAL-CANCER
KW - CLINICAL COMPLETE RESPONSE
KW - DIFFUSION-WEIGHTED MRI
KW - PREOPERATIVE CHEMORADIOTHERAPY
KW - TUMOR-REGRESSION
KW - CHEMORADIATION
KW - OUTCOMES
KW - WATCH
U2 - 10.1245/s10434-020-08334-8
DO - 10.1245/s10434-020-08334-8
M3 - Article
C2 - 32172333
SN - 1068-9265
VL - 27
SP - 2732
EP - 2739
JO - Annals of Surgical Oncology
JF - Annals of Surgical Oncology
IS - 8
ER -