The role of diffusion-weighted MRI and @entity419 PET/CT in the prediction of pathologic complete response after radiochemotherapy for XXXX : A systematic review.

@entity1 @entity419 @entity353 @entity5 @entity2286
After neoadjuvant radiochemotherapy (RCT) for locally advanced @entity5 , 15-27% of the @entity1 experience a pathological complete response (pCR). This observation raises the question as to whether invasive surgery could be avoided in a selected cohort of @entity1 who obtain a clinical complete response after preoperative RCT. In this respect, there has been growing interest in functional imaging techniques to improve clinical response assessment. This systematic review focuses on the role of @entity353 ( @entity353 ) and @entity419 positron emission tomography/computed tomography ( @entity419 PET/CT) in the prediction of pCR after RCT for @entity5 . A total of 14 publications on @entity353 and 25 on @entity419 PET/CT were retrieved. Pooled analysis of individual @entity1 data shows both imaging modalities have a low positive predictive value in the prediction of pCR (mean @entity2286 of 54% and 39% for @entity353 - and @entity419 PET/CT-based parameters respectively). Especially pre-RCT imaging is unable to predict pCR with overall accuracies of 68-72% for @entity353 and 44% for @entity419 PET/CT. Qualitative @entity353 assessment 5-10weeks after the end of RCT may outperform apparent diffusion coefficient (ADC)-based @entity353 -parameters (overall accuracy of 87% vs. 74-78%). Although few data are available, early changes in FDG-uptake seem promising in the prediction of pCR and the role of @entity419 PET/CT during RCT should be further investigated. Quantitative and qualitative @entity419 PET/CT measurements are equally effective in the assessment of pCR after RCT. The major strength of @entity353 and @entity419 PET/CT lies in the identification of non-responders who are not candidates for organ preservation. Up to now, @entity353 and @entity419 PET/CT are not accurate enough to safely select @entity1 for organ-sparing strategies. Future research must focus on the integration of functional imaging with clinical data and molecular biomarkers.
