MRI radiomics in the prediction of therapeutic response to neoadjuvant therapy for locoregionally advanced rectal cancer: a systematic review.

Introduction: The standard of care for locoregionally advanced rectal cancer is neoadjuvant therapy (NA CRT) prior to surgery, of which 10-30% experience a complete pathologic response (pCR). There has been interest in using imaging features, also known as radiomics features, to predict pCR and potentially avoid surgery. This systematic review aims to describe the spectrum of MRI studies examining high-performing radiomic features that predict NA CRT response.Areas covered: This article reviews the use of pre-therapy MRI in predicting NA CRT response for patients with locoregionally advanced rectal cancer (T3/T4 and/or N1+). The primary outcome was to identify MRI radiomic studies; secondary outcomes included the power and the frequency of use of radiomic features.Expert opinion: Advanced models incorporating multiple radiomics categories appear to be the most promising. However, there is a need for standardization across studies with regards to; the definition of NA CRT response, imaging protocols, and radiomics features incorporated. Further studies are needed to validate current radiomics models and to fully ascertain the value of MRI radiomics in the response prediction for locoregionally advanced rectal cancer.

A case of a colonic foreign body imitating diverticulitis.

We present a case of a 75-year-old male who was referred to an Emergency Department with possible diverticulitis. On further review of CT imaging, extensive sigmoid diverticulosis with mural thickening and inflammatory stranding was noted, with a linear dense foreign body present within the sigmoid lumen. The patient was managed with intravenous antibiotics and colonoscopic retrieval of the foreign body, which was lodged within a diverticulum. This case emphasizes the importance of early colonoscopic management of patients suspected to have a colonic foreign body. We then review the literature regarding colonic foreign bodies and the association with diverticulosis.