Pathak, Ram A.

TPS272 Background: Prostate-specific membrane antigen (PSMA)-targeting positron emission tomography (PET) radiopharmaceuticals enable early detection of metastatic and recurrent prostate cancer (PCa). High urinary radioactivity of some PSMA-PET agents can affect interpretation of scans in the pelvic region (prostate/prostate bed [PB]; pelvic lymph nodes [PLN]). 18 F-Piflufolastat and 18 F-flotufolastat are FDA-approved, mainly renally cleared, diagnostic PSMA-PET agents; data suggest 18 F-flotufolastat has lower urinary radioactivity than 18 F-piflufolastat, but no clinical differences have been confirmed by head-to-head intra-patient studies. The present study will directly compare the urinary radioactivity of 18 F-piflufolastat with 18 F-flotufolastat in men with low prostate-specific antigen (PSA) biochemical recurrence (BCR) of PCa after radical prostatectomy (RP). Methods: This multicenter, prospective, intra-patient comparator study will include men (≥ 18 years old) with low PSA (≤ 0.5 ng/mL) BCR of PCa who have had RP ≥ 6 months before enrollment (with undetectable PSA post surgery) and are due to have routine 18 F-piflufolastat PET. Men who have had prior 18 F-piflufolastat PET or salvage therapy, or with conditions affecting urinary output, will be excluded. Eligible patients will undergo 18 F-piflufolastat PET followed by 18 F-flotufolastat PET ≥ 24 hours but ≤ 10 days later. No diuretic will be administered for scanning purposes. Each radiopharmaceutical will be administered as a single intravenous bolus per approved US prescribing information (USPI). Scanning (with the same scanner for both scans) will start 50–90 minutes post injection of 18 F-piflufolastat and 50–70 minutes post injection of 18 F-flotufolastat. Each patient will be their own control. The primary endpoint will be difference in mean standardized uptake value (SUV mean ) between 18 F-piflufolastat and 18 F-flotufolastat as assessed in volumes of interest drawn on the urinary bladder. Secondary endpoints for both agents will include detection rates: at the patient level (overall; by baseline PSA); for local recurrences in PB subregions; and for PLN lesions. For secondary endpoints, PET scans will be interpreted per product-specific USPI by 2 specially trained, blinded, central readers (a third reader will adjudicate disagreements). Safety will be monitored until 24 hours after the second scan. Around 60 men will be screened and ≥ 52 with evaluable PET scans for both agents will be included in the primary analysis. The primary endpoint will be assessed for normality and a difference in SUV mean will be tested using 2-sided paired tests (Wilcoxon signed-rank test [non-normal]; t-test [normal]). All further endpoints, including safety, will be summarized descriptively. The trial has been open for enrollment since 10/24. Clinical trial information: NCT06604442 .

Introduction: Radical nephroureterectomy with bladder cuff excision (BCE) is the standard of care all high-risk upper tract urothelial carcinomas. With continued advancements, robot-assisted segmental ureteral resection can be employed for ureteral tumors for ipsilateral renal preservation. Herein, we are presenting our experience of different techniques classified by the affected ureteral segment, along with perioperative and intermediate to long-term functional and oncologic outcomes. Methods: From January 2008 to June 2021, a total of 17 patients underwent robot-assisted renal preserving excisional procedures for ureteral tumors. We collected and analyzed baseline, perioperative and follow-up outcomes parameters from our prospectively maintained institutional database. Eleven patients underwent segmental ureterectomy (SU) with BCE and ureteroneocystostomy with psoas hitch, five patients underwent SU with ureteroureteral anastomosis with/without psoas hitch, and one patient underwent ileal patch interposition after segmental ureteral excision. Results: Although majority of the patients had inconclusive or low-grade pathology on initial ureteroscopic biopsies, 73.33% of the patients were found to have high-grade tumors on final pathology report. Median tumor size was 2.7 cm (1–5.5 cm), and the median operative duration was 193 minutes (142–400 minutes). None of the procedures required conversion to open. Overall, only one patient (5.9%) had Clavien–Dindo grade ≥ III complication (pelvic abscess). At median follow-up of 41 months (7–156 months), four patients (26.67%) developed urothelial recurrences out of which only one patient required nephroureterectomy. Overall survival and nephroureterectomy-free survival were 86.67% and 92.31%, respectively. Conclusions: Our study provides a comprehensive review of various surgical approaches of robot-assisted renal sparing management for ureteral tumors. These procedures are surgically safe, feasible, and effective with satisfactory oncologic outcomes at intermediate to long-term follow-up. These procedures may be safely employed in select patients with a localized ureteral tumor to salvage the ipsilateral kidney and estimated glomerular filtration rate.