Beyond the Tumor Region: Peritumoral Radiomics Reshapes Prognostic Accuracy in Rectal Cancer

Motivation: The prognostic value and importance of peritumoral radiomics remain underexplored in locally advanced rectal cancer (LARC). Goal(s): To investigate the prognostic significance of peritumoral versus intratumoral radiomic features in LARC. Approach: In a retrospective cohort of 409 patients with LARC, we extracted intratumoral and peritumoral radiomic features from pretreatment high-resolution small-field-of-view T2-weighted images. Various prognostic models incorporating clinicopathological and radiomic data were constructed and compared. Variable importance was analyzed. Results: Peritumoral features demonstrated equivalent or superior prognostic value than intratumoral features, significantly enhanced accuracy of models relying on intratumoral or intratumoral-clinicpathological features. One peritumoral feature emerged as the leading predictor. Impact: Peritumoral radiomics provides equal or even greater prognostic value compared to intratumoral radiomics, promising to enhance accuracy in prognostic estimation for locally advanced rectal cancer and thus facilitating personalized treatment strategies.