Background: Upper tract urothelial carcinoma (UTUC) poses significant diagnostic challenges due to the limitations of current staging and grading techniques. Ureteroscopic (URS) biopsy is widely used preoperatively, but its accuracy, compared to final pathology, remains variable. Objectives: To evaluate the accuracy and limitations of URS biopsy in the staging and grading of UTUC, using final pathological results from radical nephroureterectomy (RNU) as the reference standard. Methods: This retrospective study included 86 patients who underwent URS biopsy followed by RNU for UTUC at a tertiary institution between 2011 and 2023. Data were collected on patient demographics, tumor characteristics, imaging, and pathology results. The accuracy of URS biopsy in staging and grading was assessed, and its associations with pathological upstaging and non-diagnostic biopsies were statistically analyzed. Results: URS biopsy correctly staged 54.69% of tumors (κ = 0.311 [0.183 – 0.439], p<0.001) and correctly graded 70.93%. (κ = 0.447 [0.303 – 0.592], p<0.001). Pathological upstaging and upgrading occurred in 39.06% and 25.58% of cases, respectively. Non-diagnostic biopsies for both stage and grade were observed in 5.81% of cases, particularly in tumors located in the renal pelvis (p=0.0064). Complementary diagnostic tools, such as computed tomography urography (CTU) and urine cytology, showed limitations, with CTU detecting invasive disease in only 14.29% of cases and urine cytology identifying high-grade tumors in 11.11%. Conclusion: URS biopsy demonstrates limitations in accurately staging and grading UTUC, resulting in a risk of both undertreatment and overtreatment. A multimodal diagnostic approach incorporating imaging, cytology, and clinical judgment is essential to optimizing management decisions and improving oncological outcomes.

Background: Muscle-invasive bladder cancer has a poor prognosis. Accurate lymph node (LN) staging is crucial, yet conventional imaging demonstrates limited sensitivity for detecting metastasis, necessitating improved pre-operative assessment. Objectives: To evaluate the diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) compared to computed tomography (CT) for LN staging in patients with bladder cancer(BC) undergoing radical cystectomy (RC), and to assess the impact of imaging-determined nodal status on survival outcomes. Methods: This retrospective study analyzed 138 patients who underwent RC and pelvic LN dissection (PLND) at a multisite tertiary institution from 2008 to 2021. All patients received either pre-operative CT or FDG-PET/CT within 8 weeks before RC and PLND. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value for detecting LN metastasis (LNM) were calculated using pathological analysis as the reference standard. Kaplan–Meier survival analysis and Cox regression were employed to assess overall survival (OS). Results: FDG-PET/CT exhibited higher sensitivity (70% vs. 23.3%) and PPV (70% vs. 38.46%) compared to CT, but lower specificity (78.57% vs. 85.7%). Survival outcomes showed statistically significant differences in OS between node-positive and node-negative groups in the FDG-PET/CT cohort, but not in the CT cohort. Conclusion: FDG-PET/CT provides superior sensitivity and PPV compared to CT for LN staging in BC, facilitating more accurate pre-operative evaluation. The improved prognostic stratification associated with FDG-PET/CT may guide individualized treatment strategies.