Diffusion Weighted Magnetic Resonance Imaging in Rectal Cancer

Ebtehal A. Mohamed, M.B.B.CH , Resident of Diagnostic Radiology , EgyptFollow
Fatma Mohamed Sherif, Diagnostic Radiology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
Wael Abdulghaffar, Diagnostic Radiology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
Ahmed M Fareed, Surgical Oncology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
Gehad A. Saleh, Diagnostic Radiology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt

Subject Area

Radiodiagnosis

Article Type

Original Study

Abstract

Background: Rectal cancer (RC) is a major cancer burden globally as it is among the tumors that are most frequently diagnosed worldwide and a significant contributor to global cancer mortality yearly. Imaging with diffusion weighting (DWI) and Magnetic resonance imaging (MRI) is the best radiological modality for the local staging and restaging of RC due to its excellent soft-tissue contrast and high spatial resolution.

Aim of the work: This study aims to assess the value of DW-MRI in staging and assessing treatment response in patients with RC who received concurrent chemoradiotherapy.

Methods: Forty-two patients with RC diagnoses were enlisted, and underwent conventional MRI and DWI in this prospective observational cohort study. Responses were rated on a scale of 0 to 5 as per the Mandard classification. The measured ADC values were analyzed; Patients were evaluated before treatment and were prospectively followed throughout neoadjuvant therapy until surgery. Treatment response was assessed longitudinally using MRI and confirmed by postoperative pathological examination. Although 42 patients were included in the study, only 25 patients underwent neoadjuvant chemoradiotherapy (nCRT) followed by surgery and were therefore eligible for treatment response analysis based on tumor regression grade (TRG).

Results: There was a significant agreement between radiology and pathology results in detecting tumor response (k= 0.761). There was a significant difference in the ADC value when compared based on T stage, N stage and EMVI. There was a significant increase in the ADC value after treatment when compared to the pre-treatment values. ADC percentage change is a superior imaging biomarker compared to baseline ADC for predicting treatment response.

Conclusions: Diffusion-weighted MRI, together with quantitative ADC measurements, is a valuable imaging tool for assessing treatment response after nCRT in cases with RC. Percent ADC change showed promise as a predictor of pathological response.

Recommended Citation

Mohamed, Ebtehal A.; Sherif, Fatma Mohamed; Abdulghaffar, Wael; Fareed, Ahmed M; and Saleh, Gehad A. (2026) "Diffusion Weighted Magnetic Resonance Imaging in Rectal Cancer," Mansoura Medical Journal: Vol. 56 : Iss. 1 , Article 3.
Available at: https://doi.org/10.58775/2735-3990.1590