Lymphadenectomy for Muscle-Invasive Bladder Cancer and Upper Tract Urothelial Cell Carcinoma

A pilot study of [18F]F-fluciclovine positron emission tomography/computed tomography for staging muscle invasive bladder cancer preceding radical cystectomy

AIM

To assess the ability of [18F]F-fluciclovine-PET/CT to stage muscle invasive bladder cancer (MIBC) before radical cystectomy.

METHODS

This single-site prospective pilot study enrolled patients with MIBC and T2-T4, N0 disease on CT/MRI slated to undergo radical cystectomy (RC). Dynamic and static [18F]F-fluciclovine-PET/CT images were acquired. Clinical readers assessed for confirmation of the primary bladder lesion on imaging and the presence of pelvic nodal metastases. Findings were compared to pathology at RC. Kinetic parameters from dynamic PET/CT were compared across bladder lesions of different clinical stages.

RESULTS

The study enrolled sixteen patients (median age: 73 years, range: 57-88 years, 11 males, 5 females), twelve receiving neoadjuvant chemotherapy before RC. There was high specificity amongst all three readers for detecting lymph node metastases (overall specificity: 0.91, 95%CI: 0.81-1.00) with good overall agreement rate with pathology (0.67, 95%CI: 0.44-0.83). The overall PPV for all readers for identifying node-positive disease was 0.4 (95%CI: 0-1.00), and the overall sensitivity was 0.13 (95%CI: 0-0.44). The overall PPV for detecting the primary tumor was 0.69 (95%CI: 0.47-0.88), and the sensitivity was 0.89 (95%CI: 0.78-1.00), with NPV and specificity being 0.70 (95%CI: 0.33, 1.00) and 0.39 (95%CI: 0.33, 0.50), respectively. Compartmental analysis of the primary bladder tumor revealed that k1 and vb parameters significantly differentiated between low (pT0-pT1) and high (pT2-pT4) risk disease (p < 0.05). Immunohistochemical assessment showed no significant correlation of tumor [18F]F-fluciclovine uptake nor kinetic parameter with amino acid transporter expression.

CONCLUSIONS

[18F]F-fluciclovine demonstrates good specificity and agreement rate for MIBC staging, with sensitivity like CT/MRI. Kinetic parameters such as k1 was able to delineate higher-stage ( ≥ = pT2) primary lesions. Heterogeneous amino acid transporter expression can be seen across lesions. Further studies are warranted to understand [18F]F-fluciclovine PET/CT use in the context of other imaging modalities in this disease.

CLINICAL TRIAL REGISTRATION

NCT04018053 Registered 2/26/2020.

A preliminary investigation of precise visualization, localization, and resection of pelvic lymph nodes in bladder cancer by using indocyanine green fluorescence-guided approach through intracutaneous dye injection into the lower limbs and perineum

Objective

This study aimed to investigate the feasibility and effectiveness of using indocyanine green (ICG) injected intracutaneously through the lower limbs and perineum for visualized tracking, localization, and qualitative assessment of pelvic lymph nodes (LNs) in bladder cancer to achieve their accurate resection.

Methods

First, ICG was injected into the LN metastasis model mice lower limbs, and real-time and dynamic in vivo and ex vivo imaging was conducted by using a near-infrared fluorescence imaging system. Additionally, 26 patients with bladder cancer were enrolled and divided into intracutaneous group and transurethral group. A near-infrared fluorescence imaging device with internal and external imaging probes was used to perform real-time tracking, localization, and resection of the pelvic LNs.

Results

The mice normal LNs and the metastatic LNs exhibited fluorescence. The metastatic LNs showed a significantly higher signal-to-background ratio than the normal LNs (3.9 ± 0.2 vs. 2.0 ± 0.1, p < 0.05). In the intracutaneous group, the accuracy rate of fluorescent-labeled LNs was 97.6%, with an average of 11.3 ± 2.4 LNs resected per patient. Six positive LNs were detected in three patients (18.8%). In the transurethral group, the accuracy rate of fluorescent-labeled LNs was 84.4%, with an average of 8.6 ± 2.3 LNs resected per patient. Two positive LNs were detected in one patient (12.5%).

Conclusion

Following the intracutaneous injection of ICG into the lower limbs and perineum, the dye accumulates in pelvic LNs through lymphatic reflux. By using near-infrared fluorescence laparoscopic fusion imaging, physicians can perform real-time tracking, localization, and precise resection of pelvic LNs.

The stratification of positive lymph nodes into pN1 and pN2 for upper urinary tract carcinoma is not prognostically significant

The 3rd-7th edition of the American Joint Committee on Cancer had 3 categories for positive lymph nodes (pN1-3) in upper urinary tract carcinomas. The 8th edition removed pN3, defining pN1 as one lymph node with a tumor deposit ≤2 cm and pN2 as a node with a tumor deposit >2 cm or metastases in multiple nodes. The aim of this study was to assess if the current pN categories impact survival in renal pelvic and ureteral carcinomas. Nephroureterectomies performed at our institution for primary upper urinary tract carcinomas between 2010 and 2019 were reviewed. Lymphadenectomy was performed in 73.3% of cases (151/206, median = 9 nodes). Eighty-one (53.6%) patients were deceased at the last review (pN0, 53 [44.5%]; pN1-2, 28 [87.5%]). There was no difference in overall or recurrence-free survival between pN1 and pN2 with 5-year overall survival (95% confidence interval) of pN0, 60.7% (52.0-70.8%); pN1, 15.4% (4.3-35.2%); and pN2, 21.1% (8.8-40.3%). The metastatic deposit size threshold of 2 cm, the number of positive lymph nodes, as well as extranodal extension did not correlate with overall or recurrence-free survival. As such, pN1 and pN2 were grouped together with a 5-year overall survival of 18.8% (9.12-28.6%). The current stratification of upper urinary tract carcinomas into pN1 and pN2 does not provide prognostic information, and both yield a stage IV classification, regardless of pT or pM category. Therefore, we recommend further simplification of pN classification into one category for regional lymph node metastasis, irrespective of the lymph node deposit size or number of positive lymph nodes.

Evaluation of the value of Preoperative Sialic Acid Levels in Diagnosis and Localization of Urothelial Tumors

Objective: To explore SA levels in the serum of urothelial tumor patients and their correlation with clinical pathological features and localization. Materials and Methods: Our research retrospectively collected data from 591 patients with urothelial tumors between July 2014 and April 2018. The SA levels in the serum of urothelial tumor patients and their correlation with clinical pathological features and localization were investigated. Univariate and multivariate logistic regression analyses were further performed to identify independent associations. Results: The levels of SA were significantly associated with the malignant degree (tumor grade and infiltration) of bladder cancer and tumor localization (all p < 0.05). The multivariate logistic regression model showed that SA levels were independently associated with the presence of high-grade urothelial carcinoma (BUC: HR = 1.941, UTUC: HR = 3.820, all p <0.05) and upper urinary tract urothelial carcinoma (HR = 2.047, p < 0.05). Finally, we validated the diagnosis and localization value of SA in an independent cohort from another institutions. Conclusions: Elevated serum SA levels are an independent predictor of high-grade urothelial carcinoma and upper urinary tract urothelial carcinoma, indicating that SA levels may be a potential biomarker for the diagnosis, prognosis and localization of urothelial tumors.