Detecting Muscle Invasion of Bladder Cancer Using a Proposed Magnetic Resonance Imaging Strategy

Abstract

Background Accurate evaluation of the invasion depth of tumors with a Vesical Imaging‐Reporting and Data System (VI‐RADS) score of 3 is difficult. Purpose To evaluate the diagnostic performance of a new magnetic resonance imaging (MRI) strategy based on the integration of the VI‐RADS and tumor contact length (TCL) for the diagnosis of muscle‐invasive bladder cancer (MIBC). Study type Single center, retrospective. Subjects A group of 179 patients with a mean age of 67 years (range, 24.0–96.0) underwent multiparametric MRI (mpMRI) before surgery, including 147 (82.1%) males and 32 (17.9%) females. Twenty‐four (13.4%), 90 (50.3%), 43 (24.0%), 15 (8.4%), and 7 (3.9%) cases were Ta, T1, T2, T3, and T4, respectively. Field Strength/Sequence A 1.5 T and 3.0 T, T2‐weighted turbo spin‐echo (TSE), single‐shot echo‐planar (SS‐EPI), diffusion‐weighted imaging (DWI), and T1‐weighted volumetric interpolated breath‐hold examination (T1‐VIBE). Assessment Three radiologists independently graded the VI‐RADS score and measured the TCL on index lesion images. A proposed MRI strategy called VI‐RADS_TCL was introduced by modifying the VI‐RADS score, which was downgraded to VI‐RADS 3F (equal to a VI‐RADS score of 2) if VI‐RADS = 3 and TCL < 3 cm. Statistical Tests Intraclass correlation coefficients (ICCs), Mann–Whitney U test, chi‐square tests, receiver operating characteristic (ROC) curves, and 2 × 2 contingency tables were applied. Results Inter‐reader agreement values were 0.941 (95% CI, 0.924–0.955) and 0.934 (95% CI, 0.916–0.948) for the TCL and VI‐RADS score. The TCL was significantly increased in the MIBC group (6.40–6.85 cm) compared with the NMIBC group (1.98–2.45 cm) (P < 0.05). The specificity and positive predictive values (PPV) of VI‐RADS_TCL were 82.46%–87.72% and 90.91%–91.59%, which were significantly greater than VI‐RADS score (P < 0.05). Additionally, 52.17%–55.88% NMIBC lesions with VI‐RADS 3 were downgraded to 3F by using VI‐RADS_TCL. Data Conclusion The proposed MRI strategy could reduce the false‐positive rate of lesions with a VI‐RADS score of 3 while retaining sensitivity. Evidence Level 4 Technical Efficacy 2

Accuracy of actual stage prediction using Vesical Imaging Reporting and Data System (VI-RADS) before radical cystectomy for urothelial carcinoma in SUPER-UC-Cx

“…However, the sensitivity rapidly decreased and reached the optimal specificity in VI-RADS score of 4. Some researchers use tumor contact length to overcome this limitation of VI-RADS (17). Another problem is that the three variables (T2-weighted, diffusion-weighted, and dynamic contrastenhanced images) in MRI are sometimes inconsistent.…”

Advances in Diagnosis and Therapy for Bladder Cancer

“…Moreover, Ahn et al noted that tumor contact length could be used as a complementary indicator for VI-RADS to predict MIBC at a threshold of 3 cm to reduce the false-positive rate [36]. A single-center retrospective study showed that the specificity of the integration of VI-RADS and tumor contact length was 82.46-87.72%, and the PPV was 90.91-91.59%, indicating an effective strategy to reduce the false-positive rate of VI-RADS [37]. Feng et al proved that the integration of fractional-order calculus model and VI-RADS increased the AUC value from 0.859 to 0.931, which helped to identify and stage BCa [38].…”