Differential performance of imaging modalities predicting pathological response to neoadjuvant chemotherapy in urothelial bladder cancer: a systematic review and meta-analysis

We assessed the differential performance of imaging modalities predicting pathological response to neoadjuvant chemotherapy (NAC) in urothelial bladder cancer (UBC).

Literature search was conducted using the MEDLINE, SCOPUS, and Cochrane Library in December 2023 to identify eligible studies.

Twenty-two studies comprising 1085 patients were selected. The pooled diagnostic odds ratio (DOR), positive likelihood ratio (LR), and negative LR of FDG positron emission tomography-computed tomography (PET/CT) for predicting bladder tumor complete pathological response (CPR) were 17.33 (95% CI: 1.65-180.99), 2.80 (95% CI: 1.04-7.57), and 0.16 (95% CI: 0.02-0.90), respectively. The pooled DOR, positive LR, and negative LR of FDG- PET/CT for predicting lymph node CPR were 5.25 (95% CI: 2.77-9.93), 1.62 (95% CI: 1.20-2.19), and 0.30 (95% CI: 0.22-0.43), respectively. The pooled DOR, positive LR, and negative LR of contrast enhanced magnetic resonance imaging (CEMRI) for predicting bladder tumor CPR were 153 (95% CI: 26.29-890.1), 16.20 (95% CI: 4.19-62.54), and 0.10 (95% CI: 0.04-0.26), respectively. The pooled DOR, positive LR, and negative LR of CEMRI for predicting lymph node CPR were 13.33 (95% CI: 1.06-166.37), 5.62 (95% CI: 0.82-38.53), and 0.42 (95% CI: 0.16-1.06), respectively.

We demonstrated that CEMRI (including mpMRI) helps accurate assessment of response to NAC in UBC. While CEMRI is a useful tool to detect residual tumor in lymph nodes, contrast enhanced CT scan and FDG-PET/CT are precise staging modality to identify nodal metastasis responders to NAC. Nevertheless, this differential diagnostic performance needs to be further refined with radiomics and novel tracers to help individualized clinical decision-making.