Correlations between Apparent Diffusion Coefficient (ADC) and Prognosis in Patients with Locally Advanced Rectal...

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Locally advanced rectal cancer (LARC) requires effective prediction of treatment response.
• Neoadjuvant chemoradiation therapy (CRT) is a standard treatment for LARC.
• Assessing treatment response and patient outcomes is crucial for optimizing LARC management.

Purpose of the Study:

• To evaluate the efficacy of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) values in predicting neoadjuvant CRT response in LARC patients.
• To determine the correlation between ADC values and tumor regression grade (TRG) and overall survival (OS).

Main Methods:

• Retrospective analysis of 94 LARC patients who underwent MRI before and after neoadjuvant CRT.
• Manual region of interest (ROI) placement on DWI sequences to derive mean ADC values.
• Correlation analysis of pre- and post-treatment ADC values with Mandard TRG and pTNM staging.
• Assessment of ADC values in relation to overall survival (OS).

Main Results:

• Post-treatment ADC and ΔADC values significantly correlated with TRG classes (p=0.002 and p=0.019, respectively).
• Post-treatment ADC values differed significantly between responders and non-responders (p=0.019).
• Pre-treatment ADC values negatively correlated with OS (p=0.001), while ΔADC positively correlated with OS (p=0.013).

Conclusions:

• Pre-treatment ADC and ΔADC values can serve as prognostic predictors for LARC patients.
• Post-treatment ADC values are valuable for predicting histopathological response and guiding conservative treatment strategies.
• ADC parameters derived from DWI show potential for personalized treatment planning in LARC.