Prediction of locally advanced rectal cancer response to neoadjuvant chemoradiation therapy using volumetric multiparametric MRI-based radiomics

PURPOSE

To assess the role of pretreatment multiparametric (mp)MRI-based radiomic features in predicting pathologic complete response (pCR) of locally advanced rectal cancer (LARC) to neoadjuvant chemoradiation therapy (nCRT).

METHODS

This was a retrospective dual-center study including 98 patients (M/F 77/21, mean age 60 years) with LARC who underwent pretreatment mpMRI followed by nCRT and total mesorectal excision or watch and wait. Fifty-eight patients from institution 1 constituted the training set and 40 from institution 2 the validation set. Manual segmentation using volumes of interest was performed on T1WI pre-/post-contrast, T2WI and diffusion-weighted imaging (DWI) sequences. Demographic information and serum carcinoembryonic antigen (CEA) levels were collected. Shape, 1st and 2nd order radiomic features were extracted and entered in models based on principal component analysis used to predict pCR. The best model was obtained using a k-fold cross-validation method on the training set, and AUC, sensitivity and specificity for prediction of pCR were calculated on the validation set.

RESULTS

Stage distribution was T3 (n = 79) or T4 (n = 19). Overall, 16 (16.3%) patients achieved pCR. Demographics, MRI TNM stage, and CEA were not predictive of pCR (p range 0.59-0.96), while several radiomic models achieved high diagnostic performance for prediction of pCR (in the validation set), with AUCs ranging from 0.7 to 0.9, with the best model based on high b-value DWI demonstrating AUC of 0.9 [95% confidence intervals: 0.67, 1], sensitivity of 100% [100%, 100%], and specificity of 81% [66%, 96%].

CONCLUSION

Radiomic models obtained from pre-treatment MRI show good to excellent performance for the prediction of pCR in patients with LARC, superior to clinical parameters and CEA. A larger study is needed for confirmation of these results.

Use of Laryngeal Mask Airway and Its Removal in a Deeply Anaesthetized State Reduces Emergence Agitation after Sevoflurane Anaesthesia in Children

This study investigated the effect of laryngeal mask airway (LMA) and removal while in a deeply anaesthetized state (deep removal) compared with endotracheal tube and extubation when awake or deeply anaesthetized on the incidence of emergence agitation in children after sevoflurane anaesthesia for subumbilical surgery. Patients (2 – 7 years) were randomly assigned to one of three groups: ET-A group ( n = 56, endotracheal tube and extubation whilst awake); ET-D group ( n = 56, endotracheal tube and deep extubation); LMA-D group (n = 56, experienced LMA and deep removal). The incidence of postoperative emergence agitation was significantly lower in the LMA-D patients compared with patients in the ET-A group (21.4% and 41.1%, respectively). Patients in the LMA-D group required a significantly shorter stay in the postanaesthetic care unit (PACU) than ET-A patients. There were no significant differences in the incidence of postoperative emergence agitation or length of stay in the PACU between the ETA and ET-D groups, or between the ET-D and LMA-D groups. In conclusion, using an LMA and deep removal decreased postoperative emergence agitation compared with using an endotracheal tube and awake extubation after paediatric sevoflurane anaesthesia.