Author of 1 Presentation
SS 8.10 - Selection of patients for organ preservation after chemoradiotherapy: MRI identifies poor responders who can go straight for surgery
Abstract
Purpose
To evaluate whether MRI is accurate to identify poor responders after chemoradiotherapy who will need straight surgery and to evaluate whether results are reproducible amongst radiologists with different levels of expertise.
Material and methods
Seven independent readers with different expertise retrospectively evaluated the restaging MRIs (T2W+DWI) of 62 patients to categorize them as [1] poor responders—highly suspicious of tumour, [2] intermediate responders—tumour most likely, and [3] good—potential (near) complete responders. Reference standard was histopathology after surgery (or long-term follow-up in case of a watch-and-wait program).
Results
Fourteen patients were complete responders, 48 had residual tumour. Median percentage of patients categorized as “poor”, “intermediate” and “good” responders by the 7 readers was 21% (range 11-37%), 50% (range 23-58%) and 29% (range 23-42%). The vast majority of the poor responders had histopathologically confirmed residual tumour (of which 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 and 29% in the MR-intermediate response group.
Conclusion
Radiologists of varying experience levels should be able to use MRI to identify the subgroup of ±20% of poor responding patients who will unavoidably require surgical resection after CRT. This may facilitate a more selective use of endoscopy, particularly in general settings or in centers with limited access to endoscopy.
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Author of 1 Presentation
SS 8.10 - Selection of patients for organ preservation after chemoradiotherapy: MRI identifies poor responders who can go straight for surgery (ID 415)
Abstract
Purpose
To evaluate whether MRI is accurate to identify poor responders after chemoradiotherapy who will need straight surgery and to evaluate whether results are reproducible amongst radiologists with different levels of expertise.
Material and methods
Seven independent readers with different expertise retrospectively evaluated the restaging MRIs (T2W+DWI) of 62 patients to categorize them as [1] poor responders—highly suspicious of tumour, [2] intermediate responders—tumour most likely, and [3] good—potential (near) complete responders. Reference standard was histopathology after surgery (or long-term follow-up in case of a watch-and-wait program).
Results
Fourteen patients were complete responders, 48 had residual tumour. Median percentage of patients categorized as “poor”, “intermediate” and “good” responders by the 7 readers was 21% (range 11-37%), 50% (range 23-58%) and 29% (range 23-42%). The vast majority of the poor responders had histopathologically confirmed residual tumour (of which 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 and 29% in the MR-intermediate response group.
Conclusion
Radiologists of varying experience levels should be able to use MRI to identify the subgroup of ±20% of poor responding patients who will unavoidably require surgical resection after CRT. This may facilitate a more selective use of endoscopy, particularly in general settings or in centers with limited access to endoscopy.