Phase 1b Trial Evaluating Tolerability and Activity of Targeted Fibroblast Growth Factor Receptor Inhibition in Localized Upper Tract Urothelial Carcinoma.

PURPOSE: We initiated a biomarker-informed preoperative study of infigratinib, a fibroblast growth factor receptor (FGFR) inhibitor, in patients with localized upper tract urothelial carcinoma (UTUC), a population with high unmet needs and tumor with a high frequency of FGFR3 alterations. MATERIALS AND METHODS: Patients with localized UTUC undergoing ureteroscopy or nephroureterectomy/ureterectomy were enrolled on a phase 1b trial (NCT04228042). Once-daily infigratinib 125 mg by mouth × 21 days (28-day cycle) was given for 2 cycles. Tolerability was monitored by Bayesian design and predefined stopping boundaries. The primary endpoint was tolerability, and the secondary endpoint was objective response based on tumor mapping, done after endoscopic biopsy and post-trial surgery. Total planned enrollment: 20 patients. Targeted sequencing performed using a NovaSeq 6000 solid tumor panel. RESULTS: From May 2021 to November 2022, 14 patients were enrolled, at which point the trial was closed due to termination of all infigratinib oncology trials. Two patients (14.3%) had treatment-terminating toxicities, well below the stopping threshold. Responses occurred in 6 (66.7%) of 9 patients with FGFR3 alterations. Responders had median tumor size reduction of 67%, with 3 of 5 patients initially planned for nephroureterectomy/ureterectomy converted to ureteroscopy. Median follow-up in responders was 24.7 months (14.9-28.9). CONCLUSIONS: In this first trial of targeted therapy for localized UTUC, FGFR inhibition was well tolerated and had significant activity in FGFR3 altered tumors. Renal preservation was enabled in a substantial proportion of participants. These data support the design of a biomarker-driven phase 2 trial of FGFR3 inhibition in this population with significant unmet clinical needs.

Magnetic resonance imaging-guided renal biopsy shows high safety and diagnostic yield: a tertiary cancer center experience.

OBJECTIVES: To evaluate the technical success and outcomes of renal biopsies performed under magnetic resonance imaging (MRI) using a closed-bore, 1.5-Tesla MRI unit. MATERIALS AND METHODS: We retrospectively reviewed our institutional biopsy database and included 150 consecutive MRI-guided biopsies for renal masses between November 2007 and March 2020. We recorded age, sex, BMI, tumor characteristics, RENAL nephrometry score, MRI scan sequence, biopsy technique, complications, diagnostic yield, pathologic outcome, and follow-up imaging. Univariate logistic regression was used to assess the association between different parameters and the development of complications. McNemar's test was used to assess the association between paired diagnostic yield measurements for fine-needle aspiration and core samples. RESULTS: A total of 150 biopsies for 150 lesions were performed in 150 patients. The median tumor size was 2.7 cm. The median BMI was 28.3. The lesions were solid, partially necrotic/cystic, and predominantly cystic in 137, eight, and five patients, respectively. Image guidance using fat saturation steady-state free precession sequence was recorded in 95% of the biopsy procedures. Samples were obtained using both fine-needle aspiration (FNA) and cores in 99 patients (66%), cores only in 40 (26%), and FNA only in three (2%). Tissue sampling was diagnostic in 144 (96%) lesions. No major complication developed following any of the biopsy procedures. The median follow-up imaging duration was 8 years and none of the patients developed biopsy-related long-term complication or tumor seeding. CONCLUSIONS: MRI-guided renal biopsy is safe and effective, with high diagnostic yield and no major complications. CLINICAL RELEVANCE STATEMENT: Image-guided renal biopsy is safe and effective, and should be included in the management algorithm of patients with renal masses. Core biopsy is recommended. KEY POINTS: • MRI-guided biopsy is a safe and effective technique for sampling of renal lesions. • MRI-guided biopsy has high diagnostic yield with no major complications. • Percutaneous image-guided biopsy plays a key role in the management of patients with renal masses.

Robotic or open superficial inguinal lymph node dissection as staging procedures for clinically node negative high risk penile cancer.

OBJECTIVE: To evaluate perioperative and oncologic outcomes of a cohort of clinically node negative high-risk penile cancer patients undergoing robotic assisted inguinal lymph node dissection (RAIL) compared to patients undergoing open superficial inguinal lymph node dissection (OSILND). PATIENTS AND METHODS: We retrospectively reviewed the clinical characteristics and outcomes of clinically node negative high-risk penile cancer patients undergoing RAIL at MDACC from 2013-2019. We sought to compare this to a contemporary open cohort of clinically node negative patients treated from 1999 to 2019 at MDACC and Moffit Cancer Center (MCC) with an OSILND. Descriptive statistics were used to characterize the study cohorts. Comparison analysis between operative variables was performed using Fisher's exact test and Wilcoxon's rank-sum test. The Kaplan-Meier method was used to estimate survival endpoints. RESULTS: There were 24 patients in the RAIL cohort, and 35 in the OSILND cohort. Among the surgical variables, operative time (348.5 minutes vs. 239.0 minutes, P < 0.01) and the duration of operative drain (37 vs. 22 days P = 0.017) were both significantly longer in the RAIL cohort. Complication incidences were similar for both cohorts (34.3% for OSILND vs. 33.3% for RAIL), with wound complications making up 33% of all complications for RAIL and 31% of complications for OSILND. No inguinal recurrences were noted in either cohort. The median follow-up was 40 months for RAIL and 33 months for OSILND. CONCLUSIONS: We observed similar complication rates and surgical variable outcomes in our analysis apart from operative time and operative drain duration. Oncological outcomes were similar between the two cohorts. RAIL was a reliable staging and potentially therapeutic procedure among clinically node negative patients with penile squamous cell carcinoma with comparable outcomes to an OSILND cohort.

Development and Validation of a Multivariable Nomogram Predictive of Post-Nephroureterectomy Renal Function.

BACKGROUND AND OBJECTIVE: The timing of perioperative nephrotoxic chemotherapy for upper tract urothelial carcinoma (UTUC) remains controversial and strongly depends on predicted platinum eligibility after radical nephroureterectomy (RNU). The study objective was to develop and validate a multivariable nomogram to predict estimated glomerular filtration rate (eGFR) following RNU. METHODS: This was a multi-institutional retrospective study of patients with UTUC treated with RNU from 2000 to 2020 at seven high-volume referral centers. Use of adjuvant chemotherapy was risk-stratified. Patients were retrospectively randomly allocated 2:1 to discovery and validation cohorts. Discovery data were used to identify independent factors associated with GFR at 1-3 mo after RNU on linear regression, and backward selection was applied for model construction. Accuracy was defined as the percentage of predicted eGFR results within 30% of the corresponding observed eGFR. KEY FINDINGS AND LIMITATIONS: We included 1100 patients, of whom 733 were in the discovery and 367 were in the validation cohort. Multivariable predictors of postoperative eGFR decline included advanced age (odds ratio [OR] -0.18, 95% confidence interval [CI] -0.28 to -0.08), diabetes (OR -2.38, 95% CI -4.64 to -0.11), and hypertension (OR -2.24, 95% CI -4.16 to -0.32). Factors associated with favorable postoperative eGFR included larger tumor size (OR 10.57, 95% CI 7.4-13.74 for tumors >5 cm vs ≤2 cm) and preoperative eGFR (OR 0.44, 95% CI 0.39-0.49). A composite nomogram predicted postoperative eGFR with good accuracy in both the discovery (80.5%) and validation (78.6%) cohorts. Limitations include exclusion of patients who received neoadjuvant chemotherapy. CONCLUSIONS: A nomogram that incorporates ubiquitous preoperative clinical variables can predict post-RNU eGFR and was validated with an independent cohort. PATIENT SUMMARY: We developed a tool that uses patient data to predict eligibility for chemotherapy after surgery to remove the kidney and ureter in patients with cancer in the upper urinary tract.

First analysis of the safety and efficacy of UGN-101 in the treatment of ureteral tumors.

OBJECTIVE: UGN-101 has been approved for the chemoablation of low-grade upper tract urothelial cancer (UTUC) involving the renal pelvis and calyces. Herein is the first reported cohort of patients with ureteral tumors treated with UGN-101. PATIENTS AND METHODS: We performed a retrospective review of patients treated with UGN-101 for UTUC at 15 high-volume academic and community centers focusing on outcomes of patients treated for ureteral disease. Patients received UGN-101 with either adjuvant or chemo-ablative intent. Response rates are reported for patients receiving chemo-ablative intent. Adverse outcomes were characterized with a focus on the rate of ureteral stenosis. RESULTS: In a cohort of 132 patients and 136 renal units, 47 cases had tumor involvement of the ureter, with 12 cases of ureteral tumor only (8.8%) and 35 cases of ureteral plus renal pelvic tumors (25.7%). Of the 23 patients with ureteral involvement who received UGN-101 induction with chemo-ablative intent, the complete response was 47.8%, which did not differ significantly from outcomes in patients without ureteral involvement. Fourteen patients (37.8%) with ureteral tumors had significant ureteral stenosis at first post-treatment evaluation, however, when excluding those with pre-existing hydronephrosis or ureteral stenosis, only 5.4% of patients developed new clinically significant stenosis. CONCLUSIONS: UGN-101 appears to be safe and may have similar efficacy in treating low-grade urothelial carcinoma of the ureter as compared to renal pelvic tumors.

The Selection for Cytoreductive Nephrectomy (SCREEN) Score: Improving Surgical Risk Stratification by Integrating Common Radiographic Features.

BACKGROUND: Careful patient selection is critical when considering cytoreductive nephrectomy (CN) for metastatic renal cell carcinoma (mRCC) but few studies have investigated the prognostic value of radiologic features that measure tumor burden. OBJECTIVE: To develop a prognostic model to improve CN selection with integration of common radiologic features with known prognostic factors associated with mortality in the first year following surgery. DESIGN, SETTINGS, AND PARTICIPANTS: Data were analyzed for consecutive patients with mRCC treated with upfront CN at five institutions from 2006 to 2017. Univariable and multivariable models were used to evaluate radiographic features and known risk factors for associations with overall survival. Relevant factors were used to create the SCREEN model and compared to the International mRCC Database Consortium (IMDC) model for predictive accuracy and clinical usefulness. RESULTS AND LIMITATIONS: A total of 914 patients with mRCC were treated with upfront CN during the study period. Seven independently predictive variables were used in the SCREEN score: three or more metastatic sites, total metastatic tumor burden ≥5 cm, bone metastasis, systemic symptoms, low serum hemoglobin, low serum albumin, and neutrophil/lymphocyte ratio ≥4. Predictive accuracy measured as the area under the receiver operating characteristic curves was 0.76 for the SCREEN score and 0.55 for the IMDC model. Decision curve analysis showed that the SCREEN model was useful beyond the IMDC classifier for threshold first-year mortality probabilities between 15% and 70%. CONCLUSIONS: The SCREEN score had higher predictive accuracy for first-year mortality compared to the IMDC scheme in a multi-institutional cohort and may be used to improve CN selection. PATIENT SUMMARY: This study provides a model to improve selection of patients with metastatic kidney cancer who may benefit from surgical removal of the primary kidney tumor. We found that radiographic measurements of the tumor burden predicted the risk of death in the first year after surgery. The model can be used to improve decision-making by these patients and their physicians.

Effectiveness of Thermal Ablation for Renal Cell Carcinoma after Prior Partial Nephrectomy.

Background: Repeat partial nephrectomy (PN) for tumors recurring in the ipsilateral kidney is associated with surgical complexity and a higher rate of complications. Objective: To evaluate the local oncologic efficacy of thermal ablation (TA) for renal cell carcinoma (RCC) in the ipsilateral kidney following PN. Design setting participation: We included patients who underwent ablation for renal tumors in the ipsilateral kidney after PN between January 2005 and December 2019. Demographics, tumor size, procedural details, complications, pathology, local oncologic outcomes, and survival outcomes are described. Outcome measurements and statistical analysis: The procedural, pathologic, and oncologic outcomes are described. Survival rates were estimated using the Kaplan-Meier method. Results and limitations: A total of 66 patients (46 male and 20 female) with a median age of 62 yr (interquartile range [IQR] 52-69) met our inclusion criteria. In these patients, 74 TA procedures were performed for 86 lesions (median tumor size 1.9 cm, IQR 1.6-2.5). Radiofrequency ablation and cryoablation accounted for 60 (81%) and 14 (19%) procedures, respectively. Three patients (3.7%) had Clavien-Dindo grade III complications. Of 65 lesion biopsies, 62 (95.5%) were diagnostic. The most common subtype was clear cell RCC (n = 37). The median imaging follow-up duration was 60 mo (IQR 43-88). Recurrence in the ablation zone occurred for four lesions (4.6%) at a median of 6.9 mo (IQR 6.4-10.7). The rates of overall, recurrence-free, and disease-free survival were 93.1%, 94.4%, and 65.6% at 5 yr, and 71.6%, 94.4%, and 60.1% at 10 yr, respectively. Limitations include the retrospective design and the lack of a control group. Conclusions: TA is effective for the treatment of RCC in the ipsilateral kidney following PN. Patient summary: Heat treatment to remove tumor tissue is an effective option for small kidney masses recurring after partial kidney removal for cancer. Long-term follow-up data revealed that this treatment resulted in low recurrence and complication rates.

Contemporary Patients Have Better Perioperative Outcomes Following Cytoreductive Nephrectomy: A Multi-institutional Analysis of 1272 Consecutive Patients.

OBJECTIVE: To evaluate factors associated with perioperative outcomes in a multi-institutional cohort of patients treated with cytoreductive nephrectomy (CN). METHODS: Data were analyzed for metastatic renal cell carcinoma patients treated with CN at 6 tertiary academic centers from 2005 to 2019. Outcomes included: Clavien-Dindo complications, mortality, length of hospitalization, 30-day readmission rate, and time to systemic therapy. Univariate and multivariable models evaluated associations between outcomes and prognostic variables including the year of surgery. RESULTS: A total of 1272 consecutive patients were treated with CN. Patients treated in 2015-2019 vs 2005-2009 had better performance status (P<.001), higher pathologic N stage (P = .04), more frequent lymph node dissections (P<.001), and less frequent presurgical therapy (P = .02). Patients treated in 2015-2019 vs 2005-2009 had lower overall and major complications from surgery, 22% vs 39%, P<.001% and 10% vs 16%, P = .03. Mortality at 90days was higher for patients treated 2005-2009 vs 2015-2019; 10% vs 5%, P = .02. After multivariable analysis, surgical time period was an independent predictor of major complications and 90-day mortality following cytoreductive surgery. CONCLUSION: Postoperative major complications and mortality rates following CN are significantly lower in patients treated within the most recent time period.

Route of Administration for UGN-101 and Impact on Oncological and Safety Outcomes.

BACKGROUND: UGN-101 can be used for chemoablation of low-grade upper tract urothelial carcinoma (UTUC). The gel can be administered via a retrograde route through a ureteral catheter or an antegrade route via a nephrostomy tube. OBJECTIVE: To report outcomes of UGN-101 by route of administration. DESIGN, SETTING, AND PARTICIPANTS: We performed a retrospective review of 132 patients from 15 institutions who were treated with UGN-101 for low-grade UTUC via retrograde versus antegrade administration. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Survival outcomes are reported per patient. Treatment, complications, and recurrence outcomes are reported per renal unit. Statistical analysis was performed for primary endpoints of oncological response and ureteral stricture occurrence. RESULTS AND LIMITATIONS: A total of 136 renal units were evaluated, comprising 78 retrograde and 58 antegrade instillations. Median follow-up was 7.4 mo. There were 120 cases (91%) of biopsy-proven low-grade UTUC. Tumors were in the renal pelvis alone in 89 cases (65%), in the ureter alone in 12 cases (9%), and in both in 35 cases (26%). Seventy-six patients (56%) had residual disease before UGN-101 treatment. Chemoablation with UGN-101 was used in 50/78 (64%) retrograde cases and 26/58 (45%) antegrade cases. A complete response according to inspection and cytology was achieved in 31 (48%) retrograde and 30 (60%) antegrade renal units (p = 0.1). Clavien grade 3 ureteral stricture occurred in 21 retrograde cases (32%) and only six (12%) antegrade cases (p < 0.01). Limitations include treatment bias, as patients in the antegrade group were more likely to undergo endoscopic mechanical ablation before UGN-101 instillation. CONCLUSIONS: These preliminary results show a significantly lower rate of stricture occurrence with antegrade administration of UGN-101, with no apparent impact on oncological efficacy. PATIENT SUMMARY: We compared results for two different delivery routes for the drug UGN-101 for treatment of cancer in the upper urinary tract. For the antegrade route, a tube is inserted through the skin into the kidney. For the retrograde route, a catheter is inserted past the bladder into the upper urinary tract. Our results show a lower rate of narrowing of the ureter (the tube draining urine from the kidney into the bladder) using the antegrade route, with no difference in cancer control.

Phase II trial of neoadjuvant sitravatinib plus nivolumab in patients undergoing nephrectomy for locally advanced clear cell renal cell carcinoma.

Sitravatinib is an immunomodulatory tyrosine kinase inhibitor that can augment responses when combined with programmed death-1 inhibitors such as nivolumab. We report a single-arm, interventional, phase 2 study of neoadjuvant sitravatinib in combination with nivolumab in patients with locally advanced clear cell renal cell carcinoma (ccRCC) prior to curative nephrectomy (NCT03680521). The primary endpoint was objective response rate (ORR) prior to surgery with a null hypothesis ORR = 5% and the alternative hypothesis set at ORR = 30%. Secondary endpoints were safety; pharmacokinetics (PK) of sitravatinib; immune effects, including changes in programmed cell death-ligand 1 expression; time-to-surgery; and disease-free survival (DFS). Twenty patients were evaluable for safety and 17 for efficacy. The ORR was 11.8%, and 24-month DFS probability was 88·0% (95% CI 61.0 to 97.0). There were no grade 4/5 treatment-related adverse events. Sitravatinib PK did not change following the addition of nivolumab. Correlative blood and tissue analyses showed changes in the tumour microenvironment resulting in an immunologically active tumour by the time of surgery (median time-to-surgery: 50 days). The primary endpoint of this study was not met as short-term neoadjuvant sitravatinib and nivolumab did not substantially increase ORR.

The ablative effect of mitomycin reverse thermal gel: Expanding the role for nephron preservation therapy in low grade upper tract urothelial carcinoma.

PURPOSE: Assess the real-world ablative effect of mitomycin reverse thermal gel for low-grade upper tract urothelial carcinoma (UTUC) in patients who undergo biopsy only or partial ablation and evaluate utility of complete ablation prior to UGN-101. MATERIAL AND METHODS: We retrospectively reviewed low-grade UTUC patients treated with UGN-101 from 15 high-volume centers. Patients were categorized based on initial endoscopic ablation (biopsy only, partial ablation, or complete ablation) and by size of remaining tumor (complete ablation, <1cm, 1-3cm, or >3cm) prior to UGN-101. The primary outcome was rendered disease free (RDF) rate at first post-UGN-101 ureteroscopy (URS), defined as complete response or partial response with minimal mechanical ablation to endoscopically clear the upper tract of visible disease. RESULTS: One hundred and sixteen patients were included for analysis after excluding those with high-grade disease. At first post-UGN-101 URS, there were no differences in RDF rates between those who at initial URS (pre-UGN-101) had complete ablation (RDF 77.0%), partial ablation (RDF 55.9%) or biopsy only (RDF 66.7%) (P = 0.14). Similarly, a complimentary analysis focusing on tumor size (completely ablated, <1cm, 1-3cm or >3cm) prior to UGN-101 induction did not demonstrate significant differences in RDF rates (P = 0.17). CONCLUSION: The results of the early real-world experience suggest that UGN-101 may play a role in initial chemo-ablative cytoreduction of larger volume low-grade tumors that may not initially appear to be amenable to renal preservation. Further studies will help to better quantify the chemo-ablative effect and to identify clinical factors for patient selection.

Mitomycin Gel (UGN-101) as a Kidney-sparing Treatment for Upper Tract Urothelial Carcinoma in Patients with Imperative Indications and High-grade Disease.

BACKGROUND: Intracavitary UGN-101 is approved for the treatment of low-grade noninvasive upper tract urothelial carcinoma (UTUC). Post-commercialization studies underscore the benefit of UGN-101 administration for patients with imperative indications for whom radical nephroureterectomy (RNU) is not a viable option. OBJECTIVE: To describe the use, efficacy, and safety of UGN-101 in patients with UTUC with imperative indications for renal preservation, including high-grade disease. DESIGN, SETTING, AND PARTICIPANTS: Patients receiving UGN-101 with imperative indications were retrospectively analyzed using a multicenter centralized registry from 15 high-volume academic and community centers. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We defined imperative indications as patients with a solitary kidney, the presence of chronic kidney disease (CKD) with a glomerular filtration rate <30 ml/min, bilateral UTUC, and patients unfit for or unwilling to undergo surgical extirpation. Tumor characteristics, disease progression/recurrence, and adverse events were recorded on a per-renal-unit basis. RESULTS AND LIMITATIONS: UGN-101 was instilled into 52 renal units (38%) in 48 patients for imperative indications, including 29 patients (56%) with a solitary kidney, 11 kidneys (21%) in the setting of bilateral UTUC, six patients (12%) with CKD, and six patients (12%) who were unfit for or unwilling to undergo RNU. Twelve renal units had biopsy-proven high-grade papillary disease. Tumors were completely ablated before induction therapy in 34% of cases, while 66% had tumor present. Following induction therapy, 17 patients (40%) had no evidence of disease (NED) on ureteroscopy, 88% of whom maintained this status at median follow-up of 10.8 mo. In the cohort with high-grade disease, five patients (45%) had NED at initial post-induction primary disease evaluation. Adverse events included pyelonephritis (8%), ureteral stenosis (8%), anemia (6%), and acute renal failure (4%). Limitations include the retrospective study design, the lack of long-term follow up, and patient selection bias. CONCLUSIONS: Intracavitary therapy with UGN-101 in patients with UTUC and imperative indications shows promise as a kidney-sparing treatment modality. While long-term follow-up is needed, this intracavitary treatment may help in prolonging time to RNU and delaying the morbidity of hemodialysis in this comorbid population. PATIENT SUMMARY: We reviewed results for patients with cancer in the upper urinary tract and an additional condition that would not allow kidney removal who received treatment with a gel called UGN-101. Our results suggest that UGN-101 shows promise as a kidney-sparing treatment. It may delay the time until kidney removal is needed in these patients and avoid the negative effects associated with dialysis.

Diagnosis and Management of Non-Metastatic Upper Tract Urothelial Carcinoma: AUA/SUO Guideline.

PURPOSE: The purpose of this guideline is to provide a useful reference on the effective evidence-based diagnoses and management of non-metastatic upper tract urothelial carcinoma (UTUC). MATERIALS/METHODS: The Pacific Northwest Evidence-based Practice Center of Oregon Health & Science University (OHSU) team conducted searches in Ovid MEDLINE (1946 to March 3rd, 2022), Cochrane Central Register of Controlled Trials (through January 2022), and Cochrane Database of Systematic Reviews (through January 2022). The searches were updated August 2022. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions (Table 1).[Table: see text]Results:This Guideline provides updated, evidence-based recommendations regarding diagnosis and management of non-metastatic UTUC including risk stratification, surveillance and survivorship. Treatments discussed include kidney sparing management, surgical management, lymph node dissection (LND), neoadjuvant/adjuvant chemotherapy and immunotherapy. CONCLUSION: This standardized guideline seeks to improve clinicians' ability to evaluate and treat patients with UTUC based on available evidence. Future studies will be essential to further support these statements for improving patient care. Updates will occur as the knowledge regarding disease biology, clinical behavior and new therapeutic options develop.

Outcomes of Radiofrequency Ablation for Solitary T1a Renal Cell Carcinoma: A 20-Year Tertiary Cancer Center Experience.

BACKGROUND: The aim is to determine the long-term oncologic and survival outcomes of the radiofrequency ablation (RFA) of solitary de novo T1a renal cell carcinoma (RCC). MATERIALS AND METHODS: We retrospectively reviewed our renal ablation registry and included only patients with new solitary, biopsy-proven T1a RCC (<4 cm) who underwent RFA from January 2001 through December 2020. We collected patient and tumor characteristics. Survival rates were estimated using the Kaplan-Meier method. RESULTS: Of the 243 patients who met our inclusion criteria (160 male and 83 female, median age 68 years), 128 (52.6%) had another primary malignancy other than renal malignancy. Two-hundred forty-three RFA procedures were performed for 243 renal tumors of a median tumor size of 2.5 cm. The median follow-up period was 3.7 years. Most tumors (68.6%) were clear cell RCC. Ten patients (4.1%) experienced Clavien-Dindo Grade III complications. Seven patients(3.1%) developed recurrence at the ablation zone, and 11 (4.5%) developed recurrence elsewhere in the kidney. The 15-year local-recurrence- and disease-free survival were 96.5% and 88.6%, respectively. The 15-year metastasis-free survival and cancer-specific survival were 100%. CONCLUSIONS: RFA is a highly effective modality for the management of T1a RCC, with low complication and recurrence rates. Long-term data revealed favorable oncologic and survival outcomes.