Nephron Sparing Treatment (NEST) for Small Renal Masses: A Feasibility Cohort-embedded Randomised Controlled Trial Comparing Percutaneous Cryoablation and Robot-assisted Partial Nephrectomy

Perioperative, functional and oncologic outcomes of percutaneous ablation versus minimally invasive partial nephrectomy for clinical T1 renal tumors: outcomes from a pooled analysis

The objective of this study was to perform a comprehensive pooled analysis aimed at comparing the efficacy and safety of percutaneous ablation (PCA) versus minimally invasive partial nephrectomy (MIPN), including robotic and laparoscopic approaches, in patients diagnosed with cT1 renal tumors. We conducted a comprehensive search across four major electronic databases: PubMed, Embase, Web of Science, and the Cochrane Library, targeting studies published in English up to April 2024. The primary outcomes evaluated in this analysis included perioperative outcomes, functional outcomes, and oncological outcomes. A total of 2449 patients across 17 studies were included in the analysis. PCA demonstrated superior outcomes compared to MIPN in terms of shorter hospital stays (WMD: - 2.13 days; 95% Confidence Interval [CI]: - 3.29, - 0.97; p = 0.0003), reduced operative times (WMD: - 109.99 min; 95% CI: - 141.40, - 78.59; p < 0.00001), and lower overall complication rates (OR: 0.54; 95% CI: 0.40, 0.74; p = 0.0001). However, PCA was associated with a higher rate of local recurrence when compared to MIPN (OR: 3.81; 95% CI: 2.45, 5.92; p < 0.00001). Additionally, no significant differences were observed in major complications, estimated glomerular filtration rate decline, creatinine variation, overall survival, recurrence-free survival, and disease-free survival between the two treatment modalities. PCA presents a notable disadvantage regarding local recurrence rates in comparison to MIPN. However, PCA offers several advantages over MIPN, including shorter durations of hospital stay, reduced operative times, and lower complication rates, while achieving similar outcomes in other oncologic metrics.

Percutaneous ablation versus robotic‑assisted partial nephrectomy for cT1 renal cell carcinoma: an evidence-based analysis of comparative outcomes

This investigation sought to conduct a comprehensive meta-analysis to assess the comparative effectiveness and safety of percutaneous ablation (PCA) versus robotic-assisted partial nephrectomy (RAPN) among individuals diagnosed with cT1 renal tumors. This study rigorously followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to conduct a systematic review and meta-analysis. A systematic search was carried out in the PubMed, Embase, Web of Science, and Cochrane Library databases, focusing on studies published in English through February 2024. We focused on evaluating primary outcomes, specifically perioperative outcomes, functional outcomes, and oncological outcomes. In this analysis, data from 1534 patients across 13 studies were evaluated. PCA was found to have advantageous outcomes in comparison to RAPN regarding hospital stay durations, with a Weighted Mean Difference (WMD) of - 2.03 days (95% Confidence Interval [CI]: -3.78 to - 0.27; p = 0.02), operative times (WMD: -106.75 min; 95% CI: - 170.78 to - 42.72; p = 0.001), and overall complication rates (Odds Ratio [OR]: 0.61; 95% CI: 0.42 to 0.89; p = 0.01). Conversely, PCA showed a higher incidence of local recurrence compared to RAPN, with an OR of 3.20 (95% CI: 1.91 to 5.35; p < 0.00001). Moreover, there were no statistically significant differences between the two treatments in terms of major complications, declines in estimated glomerular filtration rates (eGFR), variations in creatinine levels, overall survival rates, and recurrence-free survival. While PCA exhibits higher local recurrence rates than RAPN, it also presents significant advantages, such as shorter hospital stays, decreased operative durations, and lower complication rates. This juxtaposition underscores the urgent need for further, more rigorous research to substantiate these findings.

Characteristics, consent patterns, and challenges of randomized trials using the Trials within Cohorts (TwiCs) design - A scoping review

OBJECTIVES

Trials within Cohorts (TwiCs) is a pragmatic design approach that may overcome frequent challenges of traditional randomized trials such as slow recruitment, burdensome consent procedures, or limited external validity. This scoping review aims to identify all randomized controlled trials using the TwiCs design and to summarize their design characteristics, ways to obtain informed consent, output, reported challenges and mitigation strategies.

STUDY DESIGN AND SETTING

Systematic search of Medline, Embase, Cochrane, trial registries and citation tracking up to December 2022. TwiCs were defined as randomized trials embedded in a cohort with postrandomization consent for the intervention group and no specific postrandomization consent for the usual care control group. Information from identified TwiCs was extracted in duplicate from protocols, publications, and registry entries. We analyzed the information descriptively and qualitatively to highlight methodological challenges and solutions related to nonuptake of interventions and informed consent procedure.

RESULTS

We identified a total of 46 TwiCs conducted between 2005 and 2022 in 14 different countries by a handful of research groups. The most common medical fields were oncology (11/46; 24%), infectious diseases (8/46; 17%), and mental health (7/46; 15%). A typical TwiCs was investigator-initiated (46/46; 100%), publicly funded (36/46; 78%), and recruited outpatients (27/46; 59%). Excluding eight pilot trials, only 16/38 (42%) TwiCs adjusted their calculated sample size for nonuptake of the intervention, anticipating a median nonuptake of 25% (interquartile range 10%-32%) in the experimental arm. Seventeen TwiCs (45%) planned analyses to adjust effect estimates for nonuptake. Regarding informed consent, we observed three patterns: 1) three separate consents for cohort participation, randomization, and intervention (17/46; 37%); 2) combined consent for cohort participation and randomization and a separate intervention consent (10/46; 22%); and 3) consent only for cohort participation and intervention (randomization consent not mentioned; 19/46; 41%).

CONCLUSION

Existing TwiCs are globally scattered across a few research groups covering a wide range of medical fields and interventions. Despite the potential advantages, the number of TwiCs remains small. The variability in consent procedures and the possibility of substantial nonuptake of the intervention warrants further research to guide the planning, implementation, and analysis of TwiCs.

Renal Function After CT-Guided Cryoablation of Small Renal Tumours in Patients with Solitary Kidney: An Analysis of European Multinational Prospective EuRECA Registry

PURPOSE

Treatment of renal cell carcinoma (RCC) in patients with solitary kidneys remains challenging. The purpose of this multicentre cohort study was to explore how renal function is affected by percutaneous image-guided cryoablation in patients with solitary kidneys.

MATERIAL AND METHODS

Data from the European Registry for Renal Cryoablation database were extracted on patients with RCC in solitary kidneys treated with image-guided, percutaneous cryoablation. Patients were excluded if they had multiple tumours, had received previous treatment of the tumour, or were treated with more than one cryoablation procedure. Pre- and post-treatment eGFR (within 3 months of the procedure) were compared.

RESULTS

Of 222 patients with solitary kidneys entered into the database, a total of 70 patients met inclusion criteria. The mean baseline eGFR was 55.8 ± 16.8 mL/min/1.73 m2, and the mean 3-month post-operative eGFR was 49.6 ± 16.5 mL/min/1.73 m2. Mean eGFR reduction was - 6.2 mL/min/1.73 m2 corresponding to 11.1% (p = 0.01). No patients changed chronic kidney disease group to severe or end-stage chronic kidney disease (stage IV or V). No patients required post-procedure dialysis.

CONCLUSION

Image-guided renal cryoablation appears to be safe and effective for renal function preservation in patients with RCC in a solitary kidney. Following cryoablation, all patients had preservation of renal function without the need for dialysis or progression in chronic kidney disease stage despite the statistically significant reduction in eGFR. LEVEL OF EVIDENCE 3: Observational study.

Perioperative and Oncological Outcomes of Percutaneous Radiofrequency Ablation versus Partial Nephrectomy for cT1a Renal Cancers: A Retrospective Study on Groups with Similar Clinical Characteristics

Over the recent years, progress in imaging techniques has led to an increased detection of kidney tumours, including small renal masses. While surgery is still the standard of care, there is a growing interest in minimally invasive methods. Ultrasound (US)-guided percutaneous ablation is particularly attractive because it is a safe and relatively simple procedure. In this study, we investigated the results of US-guided percutaneous radiofrequency ablation (RFA) and partial nephrectomy (PN) in the treatment of cT1a renal cancers. Between August 2016 and February 2022, 271 patients with renal tumours underwent percutaneous RFA as initial treatment in our institution. In the same period, 396 patients with renal tumours underwent surgical tumour excision. For the purpose of this study, only patients with confirmed renal cancer with matched age and tumour characteristics (size, location) were selected for both groups. Thus, a group of 44 PN patients and 41 RFA patients were formed with the same qualification criteria for both groups. Parameters such as procedure length, blood loss, hospital stay, analgesics used, and pre- and post-procedural serum creatinine were compared between these groups. Patients followed up with contrast-enhanced CT. There was no significant difference in age, tumour size, tumour location, and creatinine levels between these groups. All procedures were generally well tolerated. During a median follow-up of 28 months, two cases of recurrence/residual disease were found in each group. The overall survival was 100% in both groups, and all patients were disease-free at the end of observation. Percutaneous RFA was associated with a significantly shorter procedure length and hospital stay, lower blood loss, and lower analgesics used than PN. In the selected group of renal cancer patients, US-guided percutaneous RFA was associated with a shorter hospital stay, less analgesics used, and a shorter procedure length than PN, without differences in the oncological results or kidney function.

Image-Guided Ablation of Renal Masses: Challenges to Produce High-Quality Evidence and Future Directions

Image-guided ablation (IGA) is a rapidly developing field in interventional oncology. There is some evidence suggesting IGA's non-inferiority compared with partial or radical nephrectomy for the treatment of small renal masses (SRM). However, these are mostly limited to retrospective cohort studies. This review article outlines the evidence comparing IGA to partial nephrectomy by collating the different survival measures and evaluates the challenges of producing clinical trials and high-quality evidence. The main challenges are due to the heterogeneity of SRM, patient selection bias, unstandardized endpoint and outcomes, and the lack of global practice standards. Despite the evidence thus far demonstrating that IGA stands as a non-inferior treatment modality for SRMs, exhibiting favorable short- and long-term outcomes, further robust research is needed to integrate ablation techniques into routine clinical practice with a multidisciplinary approach. There is emerging evidence that suggests randomized controlled trial in SRMs is possible, and technologies such as histotripsy as well as artificial intelligence are used in IGA.