Application of Multiparametric Magnetic Resonance Imaging (MRI) Vesical Imaging-Reporting And Data System (VI-RADS) in Bladder Tumour – Endoscopic Submucosal Dissection (BT-ESD)

Abstract Description

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Authors (including presenting author) :

1. Ka Lun LO, FHKAM (Surg) 1 2. Timothy NG, MBChB 1 3. Joseph K.M. LI, FHKAM (Surg) 1 4. Chi Fai NG, FHKAM (Surg) 1,2

Affiliation :

1. Division of Urology, North District Hospital, New Territory East Cluster Urology Unit, Prince of Wales Hospital, Shatin, Hong Kong 2. SH Ho Urology Centre, Department of Surgery, The Chinese University of Hong Kong

Introduction :

We introduced the application of Multiparametric MRI Vesical Imaging-Reporting And Data System (VI-RADS) in Bladder Tumour – Endoscopic Submucosal Dissection (BT-ESD). Bladder cancer is not an uncommon disease. About 75% of the cancers are non-muscle invasive bladder cancers (NMIBC). Transurethral resection of bladder tumor (TURBT) is currently the gold standard treatment of non-muscle invasive bladder cancer. Why do we consider to apply VI-RADS in BT-ESD? Computed Tomography Urogram (CTU) cannot guide us the muscle invasiveness of the bladder cancer. MRI VIRADS system from grade 1 to 5 predicts likelihood of muscle invasiveness of the bladder cancer. Disadvantages of TURBT are the risks of disruption of integrity of bladder cancer, bladder perforation, incomplete resection and tumor seeding. BT-ESD enables complete resection of mucosa and submucosal layers for pathologist to assess the depth of tumor invasion. Studies have shown BT-ESD has high detrusor muscle inclusion rate with no significant difference of perioperative morbidity and recurrence rates as compared with TURBT.

Objectives :

To prove the efficacy of Multiparametric MRI Vesical Imaging-Reporting And Data System (VI-RADS) in predicting the muscle invasiveness of the bladder cancer. Also, to evaluate the safety and effectiveness of Endoscopic Submucosal Dissection (BT-ESD) in resection of Ta / T1 bladder cancer.

Methodology :

BT-ESD is an En-bloc resection of bladder cancer using ERBE Hybridknife system. It consists of a flexible electrode with waterjet in the middle of the lumen. There are I-type and T-type electrodes. With the use of monopolar system, the electrode firstly marks at least 5mm clear margin circumferentially, then submucosal injection of saline to elevate the tumour, it is followed by cutting the mucosa of the previous markings circumferentially. During En-bloc dissection of the tumour, cauterisation of the bleeding vessel is done at the same time, and finally the tumour is resected completely and removed by specimen endobag.

Result & Outcome :

From March 2018 to July 2018, 10 patients were undergone BT-ESDs. 6, 1 and 3 patients had single, two and three tumours respectively. Tumours size ranged from 0.5cm to 4cm (mean size = 2cm). Tumours were distributed over later wall (4 tumours), posterior wall (5 tumours), posterolateral wall (3 tumours), bladder neck (1 tumour) and dome (4 tumours). Tumours equal or larger than 2cm had either pre-operative contrast Computed Tomography (3 cases) or multiparametric MRI (2 cases). Multiparametric MRI VI-RADS gave us more information about muscle invasiveness of the tumours without radiation. Mean operation time was 35 minutes. Estimated blood loss was less than 10ml. No bladder perforation or obturator jerk was detected. Foley was removed and patients were discharged on post-operative Day 1. Pathologies included T1 high grade transitional cell carcinoma (TCC) with muscularis propria was included (2 cases), Ta high grade TCC (2 cases), Ta low grade TCC (5 cases) and inverted papilloma (1 case). Two patients had post-operative 3-month cystoscopy surveillance which showed no bladder tumor recurrence.