VI-RADS threshold, imaging features predict bladder cancer invasiveness with nearly 100% accuracy
A new assessment of Vesical Imaging-Reporting and Data System (VI-RADS) scores and specific MRI findings could improve the management of bladder cancer.
Though bladder cancer is highly treatable when detected early, it has a high recurrence rate. High grade non-muscle invasive bladder cancer (NMIBC) is more likely to spread into the muscularis propria of the bladder wall and metastasize further, which could alter both survival odds and the chosen course of treatment.
“Assessing the histologic grade and muscle invasion of bladder cancer precisely before surgery is crucial for predicting the chances of recurrence, and it holds great clinical significance,” Chandan J. Das, with Department of Radiodiagnosis and Interventional Radiology at the All India Institute of Medical Sciences in New Dehli, and colleagues explained in their new paper in Clinical Radiology.
This is usually done via cystoscopic biopsy. However, the procedure is invasive, costly and has been associated with under-staging invasive tumors. In 2018, experts developed the VI-RADS system to help improve disease management based on MRI findings.
Research into the effectiveness of VI-RADS has varied, with some studies indicating that it yields an accuracy of 85% for predicting a cancer’s invasiveness prior to surgery, and others suggesting it lacks specificity, leading to inaccurate staging. Das and colleagues sought to investigate whether coupling a specific VI-RADS score threshold with certain image features could provide greater insight into the invasiveness of a cancer prior to surgery.
To do this, they prospectively analyzed a group of individuals in India with bladder masses who underwent 1.5T multiparametric MRI between December 2018 and April 2023. The tumors were graded using the 5-point VI-RADS system and compared alongside patients’ clinical and pathological features.
The group paid close attention to the quantitative parameters of maximum tumor diameter (DMax) and tumor contact length (TCL), in addition to setting a threshold VI-RADS score of 4.
Scores of 4 or higher as the cutoff for muscle invasion yielded a sensitivity and specificity of 94.7% and 97.2%, respectively. It also performed well in terms of positive and negative predictive values, achieving 94.7% and 97.2% accuracy.
The team found that TCL and DMax parameters (more than 3.47 cm and 1.06 cm) were also highly indicative of muscle invasion.
“The results of our study show that the VI-RADS score is a trustworthy and comprehensive scoring system, with acceptable sensitivity, specificity, and diagnostic efficacy in the detection of detrusor muscle invasion in the Indian population and greater specificity and sensitivity as compared to individual mpMRI parameters,” the group noted. “The VI-RADS provides evidence in support of the use of mpMRI in routine preoperative staging for treatment naive patients.”
Learn more about the findings here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.