APT-Weighted Imaging and ADC Histogram Analysis for Predicting Response to Neoadjuvant Chemoradiation Locally Advanced Rectal Cancer

Motivation: Early predicting the response to nCRT is important for patients with potentially curable locally advanced rectal cancer (LARC). Goal(s): To assess early treatment response and explore personalized strategies to enhance therapeutic outcomes. Approach: Using radiotherapy-induced APTw and ADC histogram before radiotherapy and after the 10th session of radiotherapy to quantitatively describe the corresponding changes. Results: The model constructed using APTw histogram features at the 10th radiotherapy session exhibited the best predictive performance (AUC 0.954), outperforming MRI-TRG (AUC 0.693) and RECIST 1.1 (AUC 0.792), which can be used for early clinical assessment of treatment response in LARC patients receiving nCRT. Impact: The histogram characteristics and characteristic change of the APTw and ADC of pre- and mid treatment can non-invasively and predict the treatment response of LARC patients undergoing nCRT, providing a novel quantitative assessment method for evaluating treatment response.