Purpose:Percutaneous ablation therapy (AT) and partial nephrectomy (PN) are successful management strategies for T1a renal cancer. Our objective was to compare AT to PN with respect to recurrence-free survival (RFS) and overall survival (OS).Materials and Methods:Patients post PN or AT for cT1aN0M0 renal cancer from 2011 – 2021 were identified from the national Canadian Kidney Cancer Information System (CKCis). Inverse probability of treatment weighting (IPTW) using propensity scores (PS) was used. The primary outcomes, RFS and OS, were compared using Kaplan-Meier log rank test analyses and Cox proportional hazard regression models.Results:275 patients underwent AT and 2,001 underwent PN, with a median follow-up of 2.0 years (IQR 0.6-4.1 years). Covariates were well balanced between the AT and PN cohorts following PS matching. Two-year RFS following IPTW PS analysis for patients undergoing AT and PN was 88.1% and 97.4% (p<0.0001) respectively, while two-year OS was 97.4% and 99.0% (p=0.7), respectively. Five-year RFS following IPTW PS analysis for patients undergoing AT and PN was 86.0% and 95.1% respectively (p=0.003), while five-year OS was 94.2% and 95.1%, respectively (p=0.9). Following IPTW PS analysis, treatment modality (PN versus AT) was a predictor for disease recurrence (HR 0.36; p=0.003) but not for overall survival (HR 0.96; p=0.9).Conclusions:With short follow-up, PN offers better RFS than AT, although no significant difference in overall survival was detected following propensity score adjustments. Both modalities can be offered to appropriately selected patients while we await a prospective randomized data.

363 Background: The potential of ablative technologies as an alternative to surgery for the treatment of small renal masses (SRMs) ≤4cm is unclear. Our objective was to evaluate the feasibility and toxicity of stereotactic body radiation therapy (SBRT) and radiofrequency ablation (RFA) for SRMs in a prospective randomized pilot trial. Methods: Patients scheduled for renal cell carcinoma (RCC) treatment at a single academic center were approached for the pilot trial, with the aim of recruiting 24 patients. Participants were assigned 1:1 to SBRT or RFA. Imaging (CT or MRI) using a renal tumor protocol is completed at 3, 6, 9, and 12 months post-procedure. Biopsies were completed prior to the procedure and at 12 months. Multiple clinical parameters were collected. Follow-up visits will occur at 6 month intervals following the trial up to 5 years. SBRT included an initial simulation session and a single image-guided treatment session with a prescribed dose of 25 Gy. RFA was conducted by either percutaneous or laparoscopic access with 2 cycles of 8 minutes duration each upon reaching target temperature. Results: Beginning in December 2019, 24 patients were recruited and randomized (SBRT = 11; RFA = 13). Eleven had SBRT, 8 RFA, 3 have not yet had treatment, and 2 became ineligible. Median age for all patients was 67 (53,85) and 17 were male. A total of 17 patients had clear cell RCC, 6 had papillary RCC (type 1), and 1 had chromophobe RCC. All patients had T1a disease. Mean procedure length (minutes) for SBRT and RFA was 15.5±7.4 and 10.5±3.9, respectively. Two patients (both SBRT) had a 12-month biopsy showing no evidence of recurrence or metastases, while two patients (1 RFA, 1 SBRT) had a 9-month CT showing no recurrence. Data are pending for the remaining patients. An early grade 2 flare-up occurred in one SBRT patient. Conclusions: Recruitment and randomization of patients with SRMs in a SBRT vs. RFA prospective trial is feasible on a timeline that allows for regular follow-up and imaging. To date, both treatment modalities have been shown to have excellent short-term safety profiles.

Introduction: Same-day discharge (SDD) following robot-assisted radical prostatectomy (RARP) is emerging as the standard of care. We conducted a systematic review and meta-analysis to evaluate the differences in perioperative characteristics, complication/readmissions rates and satisfaction/cost data between inpatient (IP) RARP and SDD RARP.Methods: This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and was prospectively registered with PROSPERO (CRD42021258848). A comprehensive search of PubMedÒ, EmbaseÒ, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov and conference abstract publications was performed. A leave-one-out sensitivity analysis was performed to control for heterogeneity and risk of bias.Results: A total of 14 studies were included with a pooled population of 3,795 patients, including 2,348 (61.9%) IP RARPs and 1,447 (38.1%) SDD RARPs. SDD pathways varied, though many commonalities were present in patient selection, perioperative recommendations and postoperative management. When compared to IP RARP, SDD RARP had no differences in !grade 3 ClavieneDindo complications (RR: 0.4, 95% CI 0.2, 1.1, p¼0.07), 90-day readmission rates (RR: 0.6, 95% CI 0.3, 1.1, p¼0.10) or unscheduled emergency department visits (RR: 1.0, 95% CI 0.3, 3.1, p¼0.97). Cost savings per patient ranged between $367 and $2,109, and overall satisfaction was high at 87.5%e100%.Conclusions: SDD following RARP is both feasible and safe, while potentially offering health care cost savings with high patient satisfaction rates. Data from this study will inform the uptake and development of future SDD pathways in contemporary urological care such that it may be offered to a broader patient population.

Introduction: We aimed to evaluate the feasibility and safety of implementing a same-day discharge (SDD) protocol for robot-assisted radical prostatectomy (RARP) and pelvic lymph node dissection. Methods: We performed a prospective cohort study including all consecutive eligible patients undergoing RARP in 2021 following initiation of SDD RARP protocol in April. Baseline characteristics were compared using t-tests, Mann-Whitney U tests, and odds ratios (OR) calculated using multiple logistic regression to assess for predictors of SDD success. Results: A total of 117 patients underwent RARP in 2021 following initiation of the SDD protocol. Fifty-seven patients were initiated on the SDD pathway, and 60 patients underwent surgery as an inpatient (IP-RARP). Of those on the SDD pathway (SDD-RARP), 33 (58%) were successfully discharged the same day of surgery, while 24 (42%) failed SDD. Baseline demographics were well-balanced between cohorts. Case order, increased patient age, and distance travelled to the hospital were factors associated with selection of patients for the IP-RARP protocol. In total, 12 SDD and 12 IP patients presented to the emergency department (p=1.0), and none within 24 hours of discharge. There were no hospital admissions in the SDD cohort, with four readmissions in the IP cohort (p=0.1). Multiple logistic regression revealed that case order (second case) was the only predictive factor for SDD success (OR 4.08, 95% confidence interval [CI] 1.59–11.62, p=0.005). Conclusions: Implementation of an SDD pathway following RARP is feasible, with no increase in rates of complications, unscheduled visits, or readmissions.

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