Accuracy of High-Frequency Endoluminal Ultrasonography for Clinical Staging of Upper Tract Urothelial Carcinoma.

Abstract

Staging of upper tract urothelial carcinoma (UTUC) remains a dilemma due to imaging and biopsy limitations leading to understaging. We seek to determine the accuracy of endoluminal ultrasound (ELUS) for clinical staging of UTUC. Patients evaluated for UTUC underwent retrograde pyelography, ureteroscopy, and ELUS. ELUS was performed using mechanical radial scanning at 20 MHz in B-mode with a 5F probe. Cine clips were evaluated by 2 radiologists blinded to ureteroscopic and pathology findings. Results were compared to pathology from nephroureterectomy. Inclusion criteria were patients who underwent nephroureterectomy without pretreatment or managed endoscopically for cTa-1 disease and were without recurrence for >1 year. From 2008 to 2013, 53 patients underwent ELUS without complication. Twenty-seven patients met inclusion criteria with conclusive ELUS imaging. ELUS accurately identified 16 of 21 patients with non-muscle invasive (MI) disease (18 pTa, 2 pT1, 1 CIS) and 1 of 6 patients with at least MI disease (2 pT2, 4 pT3). For MI disease, the positive predictive value (PPV), negative predictive value, and accuracy was 76.2%, 16.7%, and 63%, respectively, while for non-organ confined (OC) disease results were 0%, 81.8%, and 66.7%, respectively. With current technique and instrumentation, ELUS may prove useful in select cases to confirm findings of non-MI and OC disease. However, it has insufficient PPV for stage pT2-3 disease. Further studies and better instrumentation are needed before incorporation into clinical practice.