Predictive value of neoadjuvant therapy combined with VI-RADS re-scoring in bladder preservation for muscle-invasive bladder cancer.

688 Background: Radical cystectomy (RC) is standard treatment for muscle-invasive bladder cancer (MIBC). However, many patients are unwilling or unable to undergo. Therefore, trimodality treatment (TMT) containing TURBT and chemoradiotherapy is an option for MIBC. However, TMT may not fully assess the effectiveness of maximal tumor resection, which is considered an important factor affecting outcomes. Additionally, neoadjuvant chemotherapy is thought to have limited effectiveness in TMT. The study aims to assess the predictive value of mpMRI VI-RADS’s re-scoring following neoadjuvant therapy in TMT. Methods: The study prospectively selected MIBC patients from January 2021 to August 2023. Inclusion criteria: 1) pathologically confirmed muscle-invasive urothelial carcinoma; 2) age <80 years tolerable cisplatin-based chemotherapy; 3) tumor size unrestricted; 4) initial VI-RADS score of 4-5; 5) no metastasis tested by CT or MRI. Exclusion criteria: 1) anterior urethra invasion; 2) dysfunction bladder; 3) lymph node and/or distant metastasis; 4) postoperative hydronephrosis not improved; 5) absolute contraindications to chemoradiotherapy. Patients underwent maximal TURBT before or after neoadjuvant therapy with gemcitabine plus cisplatin (GC) +/- toripalimab (PD-1) or RC48 plus PD-1, following VI-RADS re-scoring, then approached concurrent bladder radiotherapy (50-64Gy) with low-dose paclitaxel (50 mg/m2, D1/week) plus cisplatin (20 mg/m2, D1-2/week). Bladder recurrence and metastasis were assessed, with follow-up until August 2024 or death. Results: The study included 14 males (82.4%) and 3 females (17.6%); median age 65 (44–76) years, median follow-up 19 (8–40) months. 12 cases were cT2N0 (70.6%), 5 cases were cT3N0 (29.4%). NAC more than 2 cycles were 11 cases (64.6%), combined with PD-1 were 3 cases (17.7%), and RC48 plus PD-1 in 4 cycles were 3 cases (17.7%). Second TURBT after above neoadjuvant therapy were 11 cases (64.6%), whose VI-RADS re-scoring were all 0 points but 3 cases with residue after (3/11, 27.3%). Neoadjuvant therapy following maximal TURBT were 6 cases (35.4%), whose re-scoring was 5 points in 2 cases (11.8%), both cPR and pathological T2; re-scoring of 4 points were 2 cases (11.8%), 2 points and 1 point was respective 1 case (5.9%), who were all cPR and pathological downstaging to T1. 3 cases recurred: 2 cases whose re-scoring were 5 points recurred at the 20 and 31 months and had salvage RC (11.8%, 2/17) ; 1 case recurred at 10 months with T1 stage (1/17), whose re-scoring was 0 points, suffering reTURBT. The 1-year disease-free survival rate for all patients was 94.1% (16/17), no metastasis and death case. Conclusions: The VI-RADS re-scoring after neoadjuvant therapy for MIBC has concordance with postoperative pathology, offer a predictive value for achieving maximal tumor resection, and provide clinical reference for bladder preservation. Clinical trial information: 2000029504.