Imaging in Upper Tract Urothelial Carcinoma: Diagnostic Accuracy of Current Modalities for Local Tumor Staging.

PURPOSE OF REVIEW: To summarize current imaging modalities for upper tract urothelial carcinoma (UTUC) and evaluate their diagnostic performance for tumor staging and risk stratification. RECENT FINDINGS: CT urography remains the diagnostic standard with excellent accuracy for tumor detection, though its reliability for local staging is limited. MR urography shows promise for assessing muscle invasion but is operator dependent. FDG-PET demonstrates value in nodal and metastatic staging rather than primary tumor evaluation. Retrograde pyelography maintains a role in tumor diagnosis in circumstances where cross-sectional imaging is unable to be performed. Emerging approaches, including radiomics and machine learning, as well as novel modalities such as endoluminal ultrasound, optical coherence tomography, and contrast-enhanced ultrasound show encouraging preliminary results but lack large-scale validation. No single modality provides accurate clinical staging in UTUC. A multimodal approach integrating imaging with clinical and endoscopic data remains essential, while emerging technologies may improve future risk stratification.