Off-clamp vs on-clamp robot-assisted partial nephrectomy: a systematic review and meta-analysis.

OBJECTIVE: To compare intra- and postoperative outcomes between off-clamp and on-clamp robot-assisted partial nephrectomy (RAPN), using data from randomised controlled trials (RCTs) or covariate-matched studies (propensity score-matched or matched-pair analysis). METHODS: A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant literature review was conducted on PubMed, EMBASE, Scopus and CENTRAL for relevant studies comparing off-clamp to on-clamp RAPN. Primary outcomes were estimated blood loss, postoperative percentage decrease in estimated glomerular filtration rate (eGFR), and margin positive rate. Secondary outcomes were operative time, postoperative eGFR, length of stay, all postoperative complications, major complications, and need for transfusion. Random-effects meta-analyses were performed to generate mean differences (MDs) or odds ratios (ORs). RESULTS: A total of 10 studies (2307 patients) were shortlisted for analysis. There was no significant difference in estimated operative blood loss between off-clamp and on-clamp RAPN (MD 21.9 mL, 95% confidence interval [CI] -0.9 to 44.7 mL; P = 0.06, I2 = 58%). Off-clamp RAPN yielded a smaller postoperative eGFR deterioration (MD 3.10%, 95% CI 1.05-5.16%; P = 0.008, I2 = 13%) and lower odds of margin positivity (OR 0.62, 95% CI 0.40-0.94; P = 0.03, I2 = 0%). No significant differences were found for all secondary outcomes. CONCLUSIONS: Off-clamp and on-clamp RAPN are similarly effective approaches for selected renal masses. Within the classic trifecta of PN outcomes, off-clamp RAPN yields similar rates of perioperative complications and may possibly offer better preservation of renal function and reduced margin-positive rates.

Rare case of stromal predominant Wilm's tumour with rhabdomyoblastic differentiation in FNAC smears.

The FNAC smear and histopathology of stromal predominant Wilm's tumour with rhabdomyoblastic Differentiation along with immunostaining in a 7-year-old male. In this paper, the diagnostic potential of FNAC in identifying rare histological variants of paediatric renal tumours is highlighted.

Significance of Charlson co-morbidity index as predictive factor for post-op complications after radical nephrectomy.

The current study planned to explore the correlation between an elevated Charlson Comorbidity Index score and post-operative complications following radical nephrectomy in patients with renal cell carcinoma. A total of 70 patients aged 30-80 years undergoing radical nephrectomy were categorised into low Charlson Comorbidity Index score <4 group A and high score >4 group B. Post-operatively, complications were noted in 21(30%) patients, with higher grades more prevalent in the group B patients (relative risk: 1.96, p=0.004). The finding underscored the importance of considering comorbidities in assessing the risk of complications following radical nephrectomy.

Post-operative flank irradiation using conformal versus highly conformal radiotherapy techniques for paediatric renal tumours: Results from the French registry PediaRT.

PURPOSE: Three-dimensional conformal RT (3D-RT) techniques are gold standard for post-operative flank radiotherapy (RT) in paediatric renal tumours. Recently, highly conformal RT (HC-RT) techniques have been implemented without comparative clinical data. The main objective of this multicentre study was to compare locoregional control (LRC) in children treated either with HC-RT or 3D-RT techniques. METHODS: Patients treated with post-operative flank RT for renal tumour registered in the national cohort PediaRT between March 2013 and September 2019 were included. Treatment and follow-up data, including toxicities and outcomes, were retrieved from the database. LRC was calculated, and dose reconstruction was performed in case of an event. RESULTS: Seventy-nine patients were included. Forty patients were treated with HC-RT and 39 with 3D-RT. Median follow-up was 4.5 years. Three patients had locoregional failure (LRF; 4%). HC-RT was not associated with a higher risk of LRF. Three-year LRC were 97.4% and 94.7% in the HC-RT and 3D-RT groups, respectively. The proportion of planning target volumes receiving 95% or more of the prescribed dose did not significantly differ between both groups (HC-RT 88%; 3D-RT 69%; p = .05). HC-RT was better achieving dose constraints, and a significant mean dose reduction was observed in the peritoneal cavity and pancreas associated with lower incidence of acute gastrointestinal toxicity. CONCLUSION: LRF after post-operative flank RT for renal tumours was rare and did not increase using HC-RT versus 3D-RT techniques. Dose to the pancreas and the peritoneal cavity, as well as acute toxicity, were reduced with HC-RT compared to 3D-RT.

Is off-clamp robot-assisted partial nephrectomy beneficial for renal function? Data from the CLOCK trial.

OBJECTIVES: To compare the functional outcomes of on- vs off-clamp robot-assisted partial nephrectomy (RAPN) within a randomized controlled trial (RCT). MATERIALS AND METHODS: The CLOCK study (CLamp vs Off Clamp the Kidney during robotic partial nephrectomy; NCT02287987) is a multicentre RCT including patients with normal baseline function, two kidneys and masses with RENAL scores ≤ 10. Pre- and postoperative renal scintigraphy was prescribed. Renal defatting and hilum isolation were required in both study arms; in the on-clamp arm, ischaemia was imposed until the completion of medullary renorraphy, while in the off-clamp condition it was not allowed throughout the procedure. The primary endpoint was 6-month absolute variation in estimated glomerular filtration rate (AV-GFR); secondary endpoints were: 12, 18 and 24-month AV-GFR; 6-month estimated glomerular filtration rate variation >25% rate (RV-GFR >25); and absolute variation in ipsilateral split renal function (AV-SRF). The planned sample size was 102 + 102 cases, after taking account crossover of cases to the alternate study arm; a 1:1 randomization was performed. AV-GFR and AV-SRF were compared using analysis of covariation, and RV-GFR >25 was assessed using multivariable logistic regression. Intention-to-treat (ITT) and per-protocol analyses (PP) were performed. RESULTS: A total of 160 and 164 patients were randomly assigned to on- and off-clamp RAPN, respectively; crossover was observed in 14% and 43% of the on- and off-clamp arms, respectively. We were unable to find any statistically significant difference between on- vs off-clamp with regard to the primary endpoint (ITT: 6-month AV-GFR -6.2 vs -5.1 mL/min, mean difference 0.2 mL/min, 95% confidence interval [CI] -3.1 to 3.4 [P = 0.8]; PP: 6-month AV-GFR -6.8 vs -4.2 mL/min, mean difference 1.6 mL/min, 95% CI -2.3 to 5.5 [P = 0.7]) or with regard to the secondary endpoints. The median warm ischaemia time was 14 vs 15 min in the ITT analysis and 14 vs 0 min in the PP analysis. CONCLUSION: In patients with regular baseline function and two kidneys, we found no evidence of differences in functional outcomes for on- vs off-clamp RAPN.

A systematic review and meta-analysis on the management of concomitant abdominal aortic aneurysms and renal tumours.

OBJECTIVES: The treatment of concomitant abdominal aortic aneurysms and renal tumours is controversial. The aim of this study was to ascertain which of the following three strategies, one-stage open aneurysm repair and nephrectomy, two-stage open aneurysm repair and nephrectomy or two-stage endovascular aneurysm repair and nephrectomy, is the best approach. METHODS: systematic review and meta-analysis of articles published between January 1992 and April 2021 describing the treatment of concomitant abdominal aortic aneurysms and renal tumours. RESULTS: A total of 1168 records were identified. After the selection process, 12 studies with data on 89 patients were included. Sixty-two patients underwent one-stage open procedures, 18 patients underwent two-stage open procedures and nine underwent two-stage endovascular procedures. The overall postoperative mortality was 0.82% (95% CI, 0.00-4.61). The postoperative mortality for one-stage open procedures was 3.09% (95% CI, 0.00-10.11). No deaths occurred in the postoperative period open two-stage procedures or two-stage endovascular procedures. The weighted postoperative morbidity for all procedures was 23.86% (95% CI, 12.64-35.08) and for open one-stage procedures was 37.40% (95% CI, 14.33-60.47). Data concerning postoperative complications of two-stage open procedures were extractable from only one patient in whom no complications were reported. Two postoperative complications were reported after two-stage endovascular procedures from a total of six patients with extractable postoperative data. We were unable to perform meta-analysis on long-term outcomes as the data were reported non-uniformly. CONCLUSION: There is currently no evidence to suggest that any procedure is associated with better outcomes. However, a one-stage open approach was the most commonly used option, favoured as it avoids delaying treatment of either of the conditions. Two-stage open procedures were preferred in cases where the surgical risk of a one-stage procedure was higher than the potential benefit. For such cases, two-stage endovascular repair is becoming more popular as a less invasive approach.

Increasing kidney grafts for transplantation.

INTRODUCTION: The current pool of organs available for transplantation does not cover requirements, for this reason non-standard risk donors need to be incorporated into the pool. In this way, donors with small renal tumour are considered for transplantation after bench tumour excision. The aim of our study was to analyse our experience in using these grafts for transplantation. MATERIALS AND METHODS: Retrospective analysis from our prospective accrued database of donors with incidental renal mass used for kidney transplantation between January 2007 and August 2018. RESULTS: Twenty kidney transplantations were performed, thirteen cases received the affected kidney (after tumour removal) and seven the contralateral kidney; from six living and eleven deceased donors. Donor and recipient median age was 58 years (range 22-82) and 56.5 years (range 38-74), respectively. Mean tumour diameter was 12.7 mm (SD 9.5). Tumours resulted in two benign lesions and fifteen renal cell carcinoma. Surgical margins were negative. Two cases presented with bleeding after reperfusion was solved without repercussion. One case presented with immediate vein thrombosis. None of them present delayed graft function. After a 69 month follow-up none of the donors or the recipients presented tumour recurrence. CONCLUSIONS: Kidneys with small incidental tumours seem to be a good option for kidney transplantation in selected patients after bench surgery excision with good functional and oncologic results. More studies and longer follow-up are needed to confirm these results.

Clear cell sarcoma of the kidney in Austrian children: Long-term survival after relapse.

INTRODUCTION: Clear cell sarcoma of the kidney (CCSK) is a rare malignant childhood renal tumour. Recently, the central nervous system (CNS) was found to be the most frequent site of relapse associated with a poor outcome. Optimal treatment strategies are scarce. PATIENTS AND METHODS: Retrospective data analysis of all Austrian children with CCSK. They were enrolled in the Austrian-Hungarian Wilms Tumour Study (AHWTS) 1989, the SIOP93-01 or the SIOP2001 study between 1990 and 2019. Demographic, diagnostic, treatment-related variables and survival data were analysed. RESULTS: We identified 12 children with CCSK (M = 7, F = 5; median age 1.6 years). All had localised disease (stage I: 2; stage II: 2; stage III: 8) at diagnosis, and a first complete remission (CR1) was achieved in 12/12. Six patients are in an ongoing CR1 (median follow-up 10 years). Six other patients had a relapse (local 1; brain 5) a median time of 2.4 years from diagnosis. Two patients died of the disease 4 months and 2.8 years after first relapse. Four of five patients with CNS relapse are in CR2 with a median follow-up time of 9.3 years after relapse diagnosis. Relapse treatment included a combination of chemotherapy, radiation and surgery. Two children received high-dose chemotherapy followed by autologous stem cell rescue, and one child received intrathecal mafosphamide. Long-term side effects after treatment were impaired tubular renal function (n = 4), cardiomyopathy (n = 1) and growth disorders (n = 1). CONCLUSIONS: In this series, the brain was the most common site of relapse. Long-term survival after recurrence was achievable with intensive multimodal therapy.

Incidence of childhood renal tumours: An international population-based study.

Malignant renal tumours represent 5% of childhood cancers and include types with likely different aetiology: Wilms tumour (WT), rhabdoid renal tumour, kidney sarcomas and renal carcinomas. WT is the most common renal tumour in children, previously shown to vary internationally and with ethnicity. Using the comprehensive database of the International Incidence of Childhood Cancer study (IICC), we analysed global variations and time trends in incidence of renal tumour types in children (age 0-14 years) and adolescents (age 15-19 years). The results were presented by 14 world regions, and five ethnic groups in the US. We included 15 320 renal tumours in children and 800 in adolescents reported to the 163 contributing registries during 2001-2010. In children, age-standardised incidence rate (ASR) of renal tumours was 8.3 per million (95% confidence interval, CI = 8.1, 8.4); it was the highest in North America and Europe (9-10 per million) and the lowest in most Asian regions (4-5 per million). In the US, Blacks had the highest ASR (10.9 per million, 95% CI = 10.2, 11.6) and Asian and Pacific Islanders the lowest (4.4 per million, 95% CI = 3.6, 5.1). In adolescents, age-specific incidence rate of renal tumours was 1.4 per million (95% CI = 1.3, 1.5). WT accounted for over 90% of all renal tumours in each age from 1 to 7 years and the proportion of renal carcinomas increased gradually with age. From 1996 to 2010, incidence remained mostly stable for WT (average annual percent change, AAPC = 0.1) and increased for renal carcinomas in children (AAPC = 3.7) and adolescents (AAPC = 3.2). Our findings warrant further monitoring.

A review of the tumour spectrum of germline succinate dehydrogenase gene mutations: Beyond phaeochromocytoma and paraganglioma.

The citric acid cycle, also known as the Krebs cycle, plays an integral role in cellular metabolism and aerobic respiration. Mutations in genes encoding the citric acid cycle enzymes succinate dehydrogenase, fumarate hydratase and malate dehydrogenase all predispose to hereditary tumour syndromes. The succinate dehydrogenase enzyme complex (SDH) couples the oxidation of succinate to fumarate in the citric acid cycle and the reduction of ubiquinone to ubiquinol in the electron transport chain. A loss of function in the succinate dehydrogenase (SDH) enzyme complex is most commonly caused by an inherited mutation in one of the four SDHx genes (SDHA, SDHB, SDHC and SDHD). This mechanism was first implicated in familial phaeochromocytoma and paraganglioma. However, over the past two decades the spectrum of tumours associated with SDH deficiency has been extended to include gastrointestinal stromal tumours (GIST), renal cell carcinoma (RCC) and pituitary adenomas. The aim of this review is to describe the extended tumour spectrum associated with SDHx gene mutations and to consider how functional tests may help to establish the role of SDHx mutations in new or unexpected tumour phenotypes.

Molecular characterisation of metanephric adenomas beyond BRAF: genetic evidence for potential malignant evolution.

AIMS: Metanephric adenomas (MAs) are conventionally regarded as rare renal tumours with indolent behaviour; limited case reports have described MAs with aggressive features. Conventional MAs harbour hotspot BRAF V600E mutations. A BRAF V600E senescence pathway, mediated by cyclin-dependent kinase inhibitor 2A (CDKN2A)/p16, has been proposed to confer MA benignity. Aside from BRAF, the molecular landscape in both conventional MAs and those with aggressive features has not been fully characterised. The aim of this study was to molecularly profile a series of MAs to investigate the correlation between genomic findings and clinical outcome. METHODS AND RESULTS: We retrospectively examined the histomorphology and patient outcomes of 11 conventional MAs and one MA with aggressive features. Each was subjected to capture-based next-generation DNA sequencing of 479 cancer-related genes and immunohistochemical profiling. All tumours were positive for WT1 immunostaining and BRAF V600E mutation. One conventional MA contained an additional somatic BRCA2 pathogenic mutation. The MA with aggressive features had a biphasic appearance: one component was epithelial, with areas morphologically consistent with conventional MA; the second component was sarcomatous, with areas of solid and angiosarcomatous growth. Differential profiling of the two populations revealed identical BRAF, EIF1AX and TERT promoter hotspot mutations in the epithelial and sarcomatous components. Deep deletion of CDKN2A and MYC amplification were identified only in the sarcomatous component. CONCLUSIONS: Although the vast majority of MAs show indolent behaviour, rare pathogenic alterations can occur in conventional MAs in addition to BRAF. Molecular profiling of a case with aggressive clinical and pathological features shows genetic evidence for malignant evolution in MAs.

Prospective analysis of laparoscopic versus open radical nephrectomy for renal tumours more than 7 cm.

AIMS: To analyse the feasibility of laparoscopic radical nephrectomy (LRN) for renal tumours >7 cm and to compare the operative and oncologic outcomes with open radical nephrectomy (ORN). SETTINGS AND DESIGN: This was a prospective, observational, comparative study. SUBJECTS AND METHODS: The study was conducted at a tertiary care super-speciality hospital. All the patients who underwent radical nephrectomy for >7 cm renal tumours during a period of 2 years (April 2012 to May 2014) were included in the study. Thirty patients were included in each ORN and LRN group. Pre-operative, intra-operative and post-operative data for all these patients were collected and analysed. STATISTICAL ANALYSIS USED: Statistical Package for the Social Sciences (SPSS, version 11.0 for Windows, Chicago, IL). RESULTS: Mean age of patients in ORN and LRN groups was 57.3 ± 6.1 years and 54.9 ± 5.7 years, respectively (P = 0.220). As compared to ORN, LRN had less drop in post-operative haemoglobin (1.39 ± 0.55 g/dl vs. 4.07 ± 1.023 g/dl, P < 0.05), less drop in haematocrit value (4.7 ± 3.25% vs. 9.5 ± 5.13%, P < 0.05), less analgesic requirement for tramadol hydrochloride (165 ± 74.5 mg vs. 260 ± 181.66 mg) and less mean hospital stay (4.2 days vs. 6.1 days, P < 0.05). There was no statistically significant difference in post-operative complication rate and recurrence-free survival over a median follow-up of 17 months (93.9% - LRN vs. 90% - ORN). CONCLUSIONS: LRN for large renal tumours is feasible and achieves oncologic outcomes similar to that obtained with ORN.

Strategies for success: a multi-institutional study on robot-assisted partial nephrectomy for complex renal lesions.

OBJECTIVE: To describe our technique, illustrated with images and videos, of robot-assisted partial nephrectomy (RAPN) for challenging renal tumours. PATIENTS AND METHODS: A study of 249 patients who underwent RAPN in multiple institutions was performed. Patients were identified using prospective RAPN databases. Complex renal lesion were defined as those with a RENAL nephrometry score ≥10. Data were analysed and differences among groups examined. RESULTS: A total of 31 (12.4%) RAPNs were performed for complex renal tumours. The median (interquartile range [IQR]) patient age was 57 (50.5-70.5) years and 21 patients (67.7%) were men. The median (IQR) American Society of Anesthesiologists score was 2 (2-3). The median (IQR) operating time was 200 (50-265) min, warm ischaemia time was 23 (18.5-29) min, and estimated blood loss was 200 (50-265) mL. There were no intra-operative complications. Two patients (6.4%) had postoperative complications. One patient (3.2%) had a positive surgical margin. The median (IQR) length of stay was 3.5 (3-5) days and the median (IQR) follow-up was 12.5 (7-24) months. There were no recurrences. RAPN resulted in statistically significant changes in renal function 3 months after RAPN compared with preoperative renal function (P < 0.001). CONCLUSION: Our results showed that RAPN was a safe approach for selected patients with complex renal tumours and may facilitate tumour resection and renorrhaphy for challenging cases, offering a minimally invasive surgical option for patients who may otherwise require open surgery.

Small renal carcinoma: the "when" and "how" of operation, active surveillance, and ablation.

Small, locally restricted renal cell carcinoma less than 4 cm in size should ideally be removed operatively by nephron-sparing tumour enucleation (partial kidney resection). In an increasingly elderly population, there is a growing trend toward parallel incidence of renal cell carcinoma and chronic renal insufficiency, with the latter's associated general comorbidities. Thus, for some patients, the risks of the anaesthesia and operation increase, while the advantage in terms of survival decreases. Transcutaneous radio-frequency ablation under local anaesthesia, transcutaneous afterloading high-dose-rate brachytherapy under local anaesthesia, and percutaneous stereotactic ablative radiotherapy may offer a less invasive alternative therapy. Active surveillance is to be regarded as no more than a controlled bridging up to definitive treatment (operation or ablation), while watchful waiting, on account of the lack of prognostic relevance and the symptomatology of renal cell carcinoma, with its comorbidity-related, clearly reduced life expectancy, does not involve any further diagnostic or therapeutic measures.

Safety, reliability and accuracy of small renal tumour biopsies: results from a multi-institution registry.

OBJECTIVE: To validate, in a multi-institution review, the safety, accuracy and reliability of renal tumour biopsy (RTB) and its role in decreasing unnecessary treatment. MATERIALS AND METHODS: We conducted a multi-institution retrospective study of patients who underwent RTB to characterize a small renal mass (SRM) between 2011 and May 2015. Patients were identified using the prospectively maintained Canadian Kidney Cancer information system. Diagnostic and concordance rates were presented using proportions, whereas factors associated with a diagnostic RTB were identified using a logistic regression model. RESULTS: Of the 373 biopsied SRMs, the initial biopsy was diagnostic in 87% of cases. Of the 47 non-diagnostic biopsies, 15 had a repeat biopsy of which, 80% were diagnostic. When both were combined, therefore, a diagnosis was obtained in 91% of SRMs. Of these, 18% were benign. Size was the only factor found to be associated with achieving a diagnostic biopsy. RTB histology and nuclear grade (high or low) were found to be highly concordant with surgical pathology (86 and 81%, respectively). Of the discordant tumours (n = 16), all were upgraded from low to high grade on surgical pathology. Adverse events were rare (<1% of cases). CONCLUSION: The present multi-institution study confirms that RTB of SRMs is safe, accurate and reliable across institutions, while decreasing unnecessary treatment. Given our findings, RTBs may be a helpful tool with which to triage SRMs and guide appropriate management.

Lesson of the month 2: IgG4-related renal mass with spontaneous resolution.

Immunoglobulin G4-related disease (IgG4-RD) is a systemic inflammatory condition that may involve any organ in the body, including the kidneys. However, renal parenchymal lesions are not seen frequently and the treatment strategy remains unclear. We describe a case of IgG4-related renal mass, which resolved spontaneously. The patient presented with right loin pain, constitutional symptoms and raised inflammatory markers. Magnetic resonance imaging (MRI) showed a large infiltrative mass centered on the right renal hilum and biopsy demonstrated histological changes in keeping with IgG4-RD. A careful 'watch-and-wait' approach was taken and at six months following initial presentation, the patient's symptoms had fully resolved and inflammatory markers had normalised. Repeat MRI showed almost complete resolution of the mass. We propose that a careful 'watch-and-wait' approach could be considered as an alternative to immune suppression for IgG4-related renal masses, especially if they are not causing symptoms or organ compromise.

A multicentre matched-pair analysis comparing robot-assisted versus open partial nephrectomy.

OBJECTIVE: To compare the perioperative, pathological and functional outcomes in two contemporary, large series of patients in different institutions and who underwent open partial nephrectomy (OPN) or robot-assisted PN (RAPN) for suspected renal tumours. PATIENTS AND METHODS: This was a retrospective, multicentre, international, matched-pair analysis comparing patients who underwent RAPN or OPN for suspected renal cell carcinoma. Data on patients who underwent OPN were extracted by an Italian observational registry collecting data from 19 different centres. Data on patients who received RAPN were extracted from a multicentre, international database collecting cases treated in four high-volume referral centres of robotic surgery. The matching was in a 1:1 ratio for the surgical approach and included 200 patients in each arm. RESULTS: The mean warm ischaemia time was shorter in the OPN group than in the RAPN group, at a mean (SD) of 15.4 (5.9) vs 19.2 (7.3) min (P < 0.001). Conversely, the median (interquartile range) estimated blood loss was 150 (100-300) mL in the OPN group and 100 (50-150) mL in the RAPN group (P < 0.001). There were no differences in operating time (P = 0.18) and the intraoperative complication rate (P = 0.31) between the approaches. Postoperative complications were recorded in 43 (21.5%) patients who underwent OPN and in 28 (14%) who received RAPN (P = 0.02). Moreover, major complications (grade 3-4) were reported in nine (4.5%) patients after OPN and in nine (4.5%) after RAPN. Positive margins were detected in nine (5.5%) patients after OPN and in nine (5.7%) after RAPN (P = 0.98). The mean (SD) 3-month estimated glomerular filtration rate declined by 16.6 (18.1) mL/min from the preoperative value in the OPN group and by 16.4 (22.9) mL/min in the RAPN group (P = 0.28). CONCLUSION: RAPN can achieve equivalent perioperative, early oncological and functional outcomes as OPN. Moreover, RAPN is a less invasive approach, offering a lower risk of bleeding and postoperative complications than OPN.

Long-term outcomes in healthy adults after radiofrequency ablation of T1a renal tumours.

OBJECTIVE: To report the long-term oncological and renal function outcomes in healthy adults treated with radiofrequency ablation (RFA) for small renal masses. MATERIALS AND METHODS: We retrospectively analysed the medical records of otherwise healthy patients (those with American Society of Anesthesiologists symptom score 1 or 2) with clinical T1a renal tumours who underwent RFA at our institution between March 2001 and July 2012. Radiographic follow-up with contrast imaging was performed at 6 weeks, 6 months, 1 year and annually thereafter. Local recurrence was defined as any new enhancing lesion (>10 HU) after the initial negative post-treatment computed tomography results. The estimated glomerular filtration rates (eGFRs) before and after RFA were calculated using the Cockgroft-Gault equation. RESULTS: We performed RFA on 58 renal tumours in 52 patients. The mean tumour size was 2.2 cm with a median (interquartile range) follow-up of 60 (48-90) months. Three (5.1%) of the treated masses had tumour recurrence after initial RFA. The 5- and 10-year recurrence-free survival rate was 94.2%. There were no recurrences after 3 years. Three (5.1%) patients died during the follow-up, which gave 5- and 10-year overall survival rates of 95.7% and 91.1%. No patient developed metastatic renal cell carcinoma (RCC) and none died from RCC. Paired analysis showed that the eGFR values at a median follow-up of 40 months did not differ significantly from those before RFA. CONCLUSION: With long-term follow-up, RFA provides durable oncological and functional outcomes for selected T1a renal tumours in otherwise healthy patients.