Canadian guidelines for postoperative surveillance of upper urinary tract urothelial carcinoma

Low-Tube-Voltage CT Urography Using Low-Concentration-Iodine Contrast Media and Iterative Reconstruction: A Multi-Institutional Randomized Controlled Trial for Comparison with Conventional CT Urography

OBJECTIVE

To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU.

MATERIALS AND METHODS

This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated.

RESULTS

The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose (5.73 ± 4.04 vs. 8.43 ± 4.38 mSv) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ≥ 3), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group.

CONCLUSION

The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.

Surveillance guidelines based on recurrence patterns for upper tract urothelial carcinoma

INTRODUCTION

Upper tract urothelial carcinoma (UTUC) accounts for 5% of all urothelial tumours. Due to its rarity, evidence regarding postoperative surveillance is lacking. The objective of this study was to develop a post-radical nephroureterectomy (RNU) surveillance protocol based on recurrence patterns in a large, multi-institutional cohort of patients.

METHODS

Retrospective clinical and pathological data were collected from 1029 patients undergoing RNU over a 15-year period (1994-2009) at 10 Canadian academic institutions. A multivariable model was used to identify prognostic clinicopathological factors, which were then used to define risk categories. Risk-based surveillance guidelines were proposed based on actual recurrence patterns.

RESULTS

Overall, 555 (49.9%) patients developed recurrence, including 289 (25.9%) in the urothelium and 266 (23.9%) with loco-regional and distant recurrences. Based on multivariable analysis, three risk groups were identified: 1) low-risk patients with pTa-T1, pN0 disease, and no adverse histological features (high tumour grade, lymphovascular invasion [LVI], tumour multifocality); 2) intermediate-risk patients with pTa-T1, pN0 disease with one or more of the adverse histological features; and 3) high-risk patients with a ≥pT2 tumour and/or nodal involvement. Low-, intermediate-, and high-risk patients were free of urothelial recurrence at three years in 72%, 66%, and 63%, respectively, and free of regional/distant recurrence in 93%, 87%, and 62%, respectively. The risks of loco-regional and distant recurrences (p<0.0001) and time to death (p<0.0001) were significantly different between the low-, intermediate-, and high-risk patients.

CONCLUSIONS

Based on recurrence patterns in a large, multicentre patient cohort, we have proposed an evidence-based, risk-adapted post-RNU surveillance protocol.

Patterns of Recurrence in Upper Tract Transitional Cell Carcinoma: Imaging Surveillance

OBJECTIVE

The objective of our study was to evaluate recurrence patterns of upper tract transitional cell carcinomas (UT-TCCs) after radical nephroureterectomy (RNU).

MATERIALS AND METHODS

Sixty-eight patients (mean age, 78 years; 34 men and 34 women) with UT-TCC after having undergone RNU from 2001 to 2008 were included in this study. Radiologic examinations and clinical notes were reviewed to record tumor location, tumor morphology, histologic T stages and grades, lymphovascular invasion (LVI) status, and surgical procedures. Five-year imaging and clinical follow-up (2001-2013) findings were noted at 3, 6, 12, 18, 24, 36, 48, 60, and more than 60 months after RNU for recurrence pattern and tumor-free survival. Kaplan-Meier survival curves and Cox regression models were used to assess tumor-free survival and to perform a multivariate analysis.

RESULTS

Forty-one postoperative recurrences were noted in 20 patients. The mean time to relapse was 16 months, and time to relapse ranged from 1 to 66 months. Tumor site (multifocal lesions involving both renal collecting system and ureter), tumor morphology (mass), T stage (muscle invasion [T2-T4]), histologic grade (grade 3), and the presence of LVI were identified as risk factors for postoperative recurrence in UT-TCC. T stage was the only independent risk factor.

CONCLUSION

Urinary tract, lymph node, liver, bone, and lung recurrences were common in patients with UT-TCC and were detected most frequently at 3-24 months. Tumor site, tumor morphology, T stage, grade, and LVI status were associated with recurrence after RNU. T stage was the only independent predictor of tumor-free survival. Close surveillance for extra-urinary tract recurrences in high-risk groups and a shorter-interval follow-up of the urinary tract in low-risk patients with adjuvant chemotherapy are recommended. Identifying recurrence patterns in UT-TCC can aid in planning an effective tailored imaging surveillance strategy.

The impact of method of distal ureter management during radical nephroureterectomy on tumour recurrence

INTRODUCTON

Radical nephroureterectomy for upper tract urothelial carcinoma (UTUC) must include some form of distal ureter management to avoid high rates of tumour recurrence. It is uncertain which distal ureter management technique has the best oncologic outcomes. To determine which distal ureter management technique resulted in the lowest tumour recurrence rate, we analyzed a multi-institutional Canadian radical nephroureterectomy database.

METHODS

We retrospectively analyzed patients who underwent radical nephroureterectomy with distal ureter management for UTUC between January 1990 and June 2010 at 10 Canadian tertiary hospitals. Distal ureter management approaches were divided into 3 categories: (1) extravesical tenting for ureteric excision without cystotomy (EXTRAVESICAL); (2) open cystotomy with intravesical bladder cuff excision (INTRAVESICAL); and (3) extravesical excision with endoscopic management of ureteric orifice (ENDOSCOPIC). Data available for each patient included demographic details, distal ureter management approach, pathology and operative details, as well as the presence and location of local or distant recurrence. Clinical outcomes included overall recurrence-free survival and intravesical recurrence-free survival. Survival analysis was performed with the Kaplan-Meier method. Multivariable Cox regression analysis was also performed.

RESULTS

A total of 820 patients underwent radical nephroureterectomy with a specified distal ureter management approach at 10 Canadian academic institutions. The mean patient age was 69.6 years and the median follow-up was 24.6 months. Of the 820 patients, 406 (49.5%) underwent INTRAVESICAL, 316 (38.5%) underwent EXTRAVESICAL, and 98 (11.9%) underwent ENDOSOPIC distal ureter management. Groups differed significantly in their proportion of females, proportion of laparoscopic cases, presence of carcinoma in situ and pathological tumour stage (p < 0.05). Recurrence-free survival at 5 years was 46.3%, 35.6%, and 30.1% for INTRAVESICAL, EXTRAVESICAL and ENDOSCOPIC, respectively (p < 0.05). Multivariable Cox regression analysis confirmed that INTRAVESICAL resulted in a lower hazard of recurrence compared to EXTRAVESICAL and ENDOSCOPIC. When looking only at intravesical recurrence-free survival (iRFS), a similar trend held up with INTRAVESICAL having the highest iRFS, followed by ENDOSCOPIC and then EXTRAVESICAL management (p < 0.05). At last follow-up, 406 (49.5%) patients were alive and free of disease.

CONCLUSION

Open intravesical excision of the distal ureter (INTRAVESICAL) during radical nephroureterectomy was associated with improved overall and intravesical recurrence-free survival compared with extravesical and endoscopic approaches. These findings suggest that INTRAVESICAL should be considered the gold standard oncologic approach to distal ureter management during radical nephroureterectomy. Limitations of this study include its retrospective design, heterogeneous cohort, and limited follow-up.