Editorial for “A Quantitative Modification of VI‐RADS for Bladder Cancer at the Ureteral Orifice: A Reader Study on MRI With Varying Experience Levels”

Bladder cancer represents one of the most lethal malignancies worldwide [1], with an incidence that varies internationally according to the prevalence of major risk factors like smoking and chronic urinary infections. Today, bladder cancer remains a profound global health dilemma. Beyond its direct toll on patient well‐being, it stands as one of the most financially burdensome cancers to treat, driven by high recurrence rates that persist even in early‐stage disease [2].

A proper staging of bladder cancer hinges on distinguishing non–muscle‐invasive bladder cancer (NMIBC) from muscle‐invasive bladder cancer (MIBC), as this differentiation directly influences prognosis, therapeutic strategy, and cancer‐specific survival.

Traditionally, assessment of muscle invasion has relied on histopathological surgical specimens obtained by transurethral resection of bladder tumor (TURBT), which has long been considered the gold standard for initial staging [3]. However, this approach may present limitations. The absence of the muscle layer (detrusor muscle) in the surgical specimen, excessive cauterization, multifocal lesions, and incomplete resection frequently result in tumor understaging. For T1 tumors a repeat TURBT is always recommended to detect residual tumor or the presence of cancer cells in the muscle layer, increasing morbidity, healthcare costs, and delaying definitive treatment [4].

Since the advent of the Vesical Imaging Reporting and Data System (VI‐RADS) in 2018, the role of MRI in bladder cancer staging has expanded and has already been incorporated into some international guidelines [5]. Although robust data in the literature have confirmed the excellent reproducibility and accuracy of VI‐RADS for detecting muscle‐ invasive disease, with a recent meta‐analysis demonstrating an accuracy of 0.93 (95% CI: 0.90–0.95), some limitations concerning the clinical utility of this scoring system persist [6, 7].

A crucial limitation is the lower accuracy observed among less experienced readers, particularly in lesions located in the bladder trigone and near the ureteral meatus. The reduced accuracy observed has been attributed to several factors [8]: (a) the oblique course of the intramural ureter through the bladder wall before entering the bladder lumen; (b) the convergence and multidirectional orientation of the trigonal and ureteral muscle fibers, which can hinder accurate delineation of the muscularis propria on imaging, thereby reducing visibility of tumor extension; and (c) in the presence of hydronephrosis, the area of low signal intensity on DWI between the tumor and the bladder wall may be erroneously interpreted as an intact muscle layer, leading to a false‐negative diagnosis. Consequently, staging interpretation becomes less reliable, and interobserver variability may increase, with non‐muscle invasive bladder tumors mimicking muscle invasive disease. The recent article by Guo et al. [9], published in JMRI, aimed to address this issue.

The authors evaluated a quantitative modification of the VI‐RADS scoring system to improve assessment of lesions involving the ureteral orifice. Among the qualitative and quantitative imaging parameters assessed, their results demonstrated that only the incorporation of tumor‐contact length and stalk width into the VI‐RADS score yielded improved diagnostic performance for muscle‐invasive bladder cancer at the ureteral meatus. However, this benefit was observed only among less experienced radiologists. Nevertheless, this finding is valuable, as this group is more likely to struggle when assigning VI‐RADS categories.

Some limitations of the study by Guo et al. [9] should be acknowledged. The reduced number of patients, retrospective design, and single‐center enrollment represent major drawbacks and should be considered before the widespread dissemination of the results. In addition, the reference standard used in the study, the histopathological assessment of muscle layer status based on TURBT specimens, is itself known to have a substantial false‐negative rate in special situations.

The clinical relevance of trigonal and paraureteral tumors is considerable. These lesions are more frequently associated with advanced pathological stage, nodal involvement, lymphatic spread, and poorer oncologic outcomes. Furthermore, the presence of hydronephrosis at diagnosis is frequently associated with advanced disease and possible extravesical extension [10]. From a surgical standpoint, achieving complete TURBT in these locations can be technically challenging. Limited endoscopic procedures visualization of the trigone due to prostatic enlargement and the fear of ureteral injury and subsequent stenosis can result in incomplete resection, resulting in understaging [10].

Despite the introduction of VI‐RADS, which has profoundly impacted the preoperative staging in bladder cancer, trigonal and periureteral orifice lesions still represent a challenging scenario; efforts to improve MRI accuracy in this setting are more than welcome. Given the current limitations of MRI (and VI‐RADS categories) in these anatomic regions today, MRI findings should always be interpreted with caution and in conjunction with other variables, such as the presence or absence of hydronephrosis, cystoscopy findings, and TURBT quality.

Conflicts of Interest

The authors declare no conflicts of interest.