Microwave versus cryoablation and radiofrequency ablation for small renal mass: a multicenter comparative analysis

Impact of thermal ablation/cryoablation treatment on prognosis among patients with kidney cancer: a SEER database-based cohort study

BACKGROUND

Radiofrequency ablation (RFA) and cryoablation are minimally invasive treatments for renal cell carcinoma (RCC). However, their comparative efficacy remains under evaluation. This study aims to compare overall survival (OS) and cancer-specific survival (CSS) outcomes using data from the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

This retrospective cohort study included patients diagnosed with T1a-bN0M0 RCC from the SEER database (2004-2018). Propensity score matching was used to control for confounders, including age, sex, and tumor characteristics. Cox proportional hazards regression was applied to assess OS and CSS.

RESULTS

A total of 3768 patients were analyzed, including 3499 with T1a and 269 with T1b tumors. Patients aged > 65 years and those with T1b tumors exhibited significantly lower OS and CSS (P < 0.001). RFA was associated with reduced OS compared to cryoablation (P = 0.012). Multivariate analyses further confirmed that elderly patients, particularly those with T1b tumors, experienced worse OS (P = 0.0104) and CSS (P = 0.008) following RFA compared to cryoablation. Subgroup and competing risk analyses consistently demonstrated lower cumulative mortality in the cryoablation group.

CONCLUSIONS

Cryoablation offers superior survival outcomes compared to RFA for T1a and T1b RCC, particularly in elderly patients. These findings support cryoablation as the preferred minimally invasive treatment for early-stage kidney cancer.

A Trifecta-Based Evaluation of Patients Treated with Percutaneous Thermal Ablation of Small Renal Masses

Background: Scoring metrics are important to compare outcomes of different percutaneous treatments for small renal masses (RMs). The concept of trifecta (no complications, kidney function preservation, and absence of local recurrence) has been recently introduced in percutaneous thermal ablation of RM. In this context, previous studies have shown that cryoablation (CA) and microwave ablation (MWA) have similar outcomes. We aimed to validate the trifecta in CA and MWA and factors associated with treatment success. Materials and Methods: A retrospective comparative analysis of two cohorts was carried out on 190 consecutive patients with RMs treated using percutaneous CA or MWA. Nephrometry scores described RM complexity. Postoperative complications were categorized according to the Clavien-Dindo system. Glomerular filtration rate (GFR) at the last follow-up was calculated through the chronic kidney disease-epidemiology collaboration (EPI) formula, whereas detection of contrast enhancement during follow-up defined local recurrence. Last, trifecta was defined by the combination of no major (Clavien >2) complications, estimation of GFR (eGFR) decline <10%, and absence of local recurrence. Descriptive statistics and logistic regression models tested the association between predictors and trifecta achievement. Factors associated with recurrence were compared by the log-rank test. Results: Of 175 patients, 121 (69.1%) and 54 (30.8%) patients underwent CA and MWA, respectively. Median (interquartile range [IQR]) age and RM diameter were 75 years (66-80) and 2.4 cm (1.8-3.0). The CA group had a lower preoperative GFR but also had a lower rate of comorbidities (both p = 0.01). Other demographics and tumor characteristics were comparable between groups. In the CA and MWA groups, major complications occurred after 1.6% and 4.8% of procedures (p = 0.33), whereas an eGFR decline >10% was found in 31.5% and 38.8% of cases (p = 0.40), respectively. Similarly, in the CA and MWA groups, at a median follow-up of 21 (8-39) and 24 (9.5-36) months, local recurrence was observed after 10 (8.3%) and 5 (9.3%) cases (p = 0.78), trifecta was accomplished after 72 (59.5%) and 32 (59.3%; p = 1.00) procedures, respectively. Of note, recurrence-free survival (RFS) was comparable among groups (p = 0.57). Moreover, trifecta achievement was comparable when stratifying for demographics and tumor characteristics in the whole cohort and in the CA group (p > 0.05). Conversely, logistic regression showed a lower odds ratio (OR) of trifecta for lesions close to renal collecting system treated by MWA, even when accounting for maximum diameter and preoperative GFR (OR 0.21, confidence interval 0.60-0.72, p = 0.010). Of note, this factor was also associated with a significantly lower RFS (log-rank p = 0.002). Conclusions: Both percutaneous CA and MWA of RM can safely accomplish good oncological outcomes while preserving renal function. Approximately 6 out of 10 patients achieved trifecta after each procedure. Patient selection should account for tumor proximity to the collecting system, as this factor seems to impact the outcomes of MWA.

Comparative efficacy and safety of ablative therapies in the management of primary localised renal cell carcinoma: a systematic review and meta-analysis

BACKGROUND

Non-invasive and minimally invasive ablative treatments, including stereotactic body radiotherapy (SBRT), radiofrequency ablation, microwave ablation, and cryoablation, have emerged as key treatment options for managing renal cell carcinoma, especially for patients who are unsuitable for surgery. We aimed to compare the clinical efficacy and safety of these emerging treatment methods in patients with localised renal cell carcinoma.

METHODS

In this systematic review and meta-analysis, we searched PubMed (MEDLINE), Embase, and the Cochrane Library for publications between Jan 1, 2000, and March 1, 2024. Eligible articles were observational studies and randomised controlled trials including at least five adult patients (age ≥18 years) with primary and localised renal cell carcinoma treated with SBRT, radiofrequency ablation, microwave ablation, or cryoablation and that reported on local control outcomes. Two reviewers independently screened titles and abstracts and then full texts of eligible studies were independently evaluated by the same reviewers, with disagreements resolved via discussion or consultation with a third reviewer. Summary estimates were extracted from published reports manually using a standardised data extraction form. The primary endpoint was local control rate at 1 year, 2 years, and 5 years after start of treatment. A meta-analysis was conducted using a DerSimonian and Laird model to summarise local control rates. Publication bias was evaluated using funnel plots and Egger's test. We also recorded the frequency and severity of adverse events after treatment on the basis of the Common Terminology Criteria for Adverse Events (version 5.0) and Clavien-Dindo complication index. The study protocol was prospectively registered with PROSPERO, CRD42024511840.

FINDINGS

We identified 6668 records, of which 330 were assessed via full-text review, and 133 were included in our systematic review and meta-analysis. The eligible studies included data for 8910 patients (mean age 67·9 years [SD 7·3], 2518 [31·4%] of 8018 patients with available data were female and 5500 [68·6%] were male). Local control rates for SBRT were 99% (95% CI 97-100; I2=6%) at 1 year, 97% (95-99; I2=0%) at 2 years, and 95% (89-98; I2=42%) at 5 years; for radiofrequency ablation were 96% (94-98; I2=73%) at 1 year, 95% (92-98; I2=77%) at 2 years, and 92% (88-96; I2=78%) at 5 years; for microwave ablation were 97% (95-99; I2=74%) at 1 year, 95% (92-98; I2=77%) at 2 years, and 86% (75-94; I2=66%) at 5 years; and for cryoablation were 95% (93-96; I2=61%) at 1 year, 94% (91-96; I2=69%) at 2 years, and 90% (87-93; I2=74%) at 5 years. The proportion of patients who reported grade 3-4 adverse events was 3% (121 of 3726) after cryoablation, 2% (39 of 2503) after radiofrequency ablation, 1% (22 of 2069) after microwave ablation, and 2% (11 of 612) after SBRT. Risk of bias was moderate in most studies (70 [53%] of 133) and no publication bias was observed.

INTERPRETATION

All investigated ablative methods continue to represent effective treatment choices in renal cell carcinoma, and these findings support multi-disciplinary discussions of these treatment methods, along with surgery and surveillance, to individualise treatment decisions in these patients. Future research should aim to conduct randomised controlled trials across larger patient populations to further elucidate the long-term oncological and survival outcomes associated with these treatments.

FUNDING

None.

Percutaneous Image-Guided Ablation of Renal Cancer: Traditional and Emerging Indications, Energy Sources, Techniques, and Future Developments

Percutaneous image-guided ablation (IGA) has emerged as an established alternative to surgical management for small renal masses. This comprehensive review examines traditional and emerging indications, energy sources, techniques, and future developments in IGA for renal cancer treatment. Traditionally, IGA has been indicated for frail or comorbid patients, those with solitary kidneys or chronic kidney disease, and those with histologically proven renal cell carcinomas less than 4 cm in size. Recent evidence supports expanding these indications to include T1b or T2 tumours and hereditary or recurrent renal cell carcinomas. The use of IGA combined with pre-ablation transarterial embolisation is discussed herein. This review then explores traditional energy sources including radiofrequency ablation, cryoablation, and microwave ablation, highlighting their respective advantages and limitations. Emerging technologies such as irreversible electroporation and histotripsy, as promising alternatives, are then presented, highlighting their advantage of being able to treat tumours near critical structures. Future research priorities highlight the need to establish high-quality evidence through innovative trial designs, as well as taking patient-reported outcome measures into account. Health economic considerations are key to ensuring that ablation therapies are cost-effective. The integration of artificial intelligence and radiomics shows vast potential for improving patient selection and treatment outcomes. Additionally, the immunomodulatory effects of ablative therapies suggest possible synergistic benefits when combined with immunotherapy which also require exploration in future research. Technological advancement and research developments will continue to broaden the role of IGA in clinical practice.

Salvage stereotactic ablative body radiotherapy after thermal ablation of primary kidney cancer

OBJECTIVE

To evaluate the effectiveness and safety of salvage stereotactic ablative body radiotherapy (SABR) for recurrent renal cell carcinoma (RCC) after thermal ablation (TA).

MATERIALS AND METHODS

This study was a multi-institutional retrospective analysis of patients with recurrent RCC following TA who received SABR between 2016 and 2020. The primary study outcome was freedom from local failure, evaluated radiographically based on Response Evaluation Criteria in Solid Tumours (RECIST) v1.1. Distant failure, cancer-specific survival (CSS), overall survival (OS), treatment-related toxicity and renal function changes following SABR were the secondary outcomes. The Kaplan-Meier method was used to estimate freedom from local and distant failure, CSS and OS.

RESULTS

Seventeen patients with 18 biopsy-confirmed RCCs were included, with a median (interquartile range [IQR]) age at time of SABR of 75.2 (72.6-68.7) years, a median (IQR) tumour size of 3.5 (1.9-4.1) cm and follow-up (reverse Kaplan-Meier method) of 3.36 (95% confidence interval [CI] 1.6-4.1) years. Six of the 17 patients had a solitary kidney. Five patients had failed repeat TA prior to SABR. The median (IQR) time from TA procedure to SABR was 3.03 (1.5-5.1) years. No patient experienced local progression, with a local control rate of 100%. Four patients, two with baseline metastatic disease, experienced distant progression. The distant progression-free survival, CSS and OS at 3 years were 72.1% (95% CI 51.9%-100%), 92.3% (95% CI 78.9%-100%) and 82.1% (95% CI 62.1%-100%), respectively. The median (IQR) glomerular filtration rate before SABR was 58 (40-71) mL/min, and at last follow-up, it was 48 (33-57) mL/min. No patient experienced grade 3+ toxicity or went on to develop end-stage renal disease.

CONCLUSION

The results showed that SABR appears to be an effective and safe salvage strategy in patients with recurrent RCC following TA.

Thermal Ablation for Small Renal Masses: Identifying Anthropometric Factors for Predicting Perioperative and Oncological Outcomes

OBJECTIVES

To test for specific anthropometric parameters to predict perioperative outcomes after thermal ablation (TA) for renal cell carcinoma (RCC).

MATERIALS AND METHODS

Retrospective single center (2008-2022) analysis of 538 T1a-b RCC patients treated with TA. We tested for specific anthropometric parameters, namely skin to tumor distance (STTD), perirenal fat thickness (PFT), median psoas muscle axial area (PMAA) and median paravertebral muscle axial area (PVMAA), to predict TRIFECTA achievement: (1) absence of CLAVIEN-DINDO≥ 3 complications; (2) complete ablation; (3) absence of ≥ 30% decrease in eGFR. Univariable (ULRM) and multivariable logistic regression models (MLRM) were used for testing TRIFECTA achievement.

RESULTS

Overall, 103 patients (19%) did not achieve TRIFECTA. Of all anthropometric factors, only lower PMAA was associated with no TRIFECTA achievement (10 vs. 11 cm2, P = .02). However, ULRMs and MLRMs did not confirmed the aforementioned association. We than tested for the 3 specific TRIFECTA items. In separate ULRM and MLRM predicting incomplete ablation, both continuously coded STTD (Odds Ratio [OR]: 1.02; CI: 1.01-1.03; P = .02) and STTD strata (STTD > 10 cm; OR: 2.1; CI: 1.1-4.1; P = .03) achieved independent predictor status. Conversely, in separate ULRM and MLRM predicting CLAVIEN-DINDO ≥3 complications, both continuously coded PFT (OR: 1.04; CI: 1.01-1.07; P = .01) and PFT strata (PFT ≥ 14 mm; OR: 3.3; CI: 1.6-10.2; P = .003) achieved independent predictor status. Last, none of the anthropometric parameters were associated with eGFR decrease ≥ 30%.

CONCLUSION

None of the tested anthropometric parameters predicted TRIFECTA achievement. However, when the 3 specific TRIFECTA items were tested, STTD and PFT were associated with, respectively, incomplete ablation and CLAVIEN-DINDO ≥ 3 complications.

Successful treatment of a rheumatoid arthritis patient with severe synovial hypertrophy and impaired shoulder function with microwave ablation technique

Rheumatoid arthritis (RA) is a chronic, inflammatory systemic disorder of synovial joints and results in polyarthritis, chronical degeneration, and finally deformities and ankylosis in severe cases. Synovitis and pannus formation are results of inflammatory changes and lead into restriction in joint movement. Shoulders are among the later affected and larger joints and formation of synovitis in early active stages and pannus in later stages might be concluded with frozen shoulder and severe impairment in functionality. These late-term changes cannot be controlled with systemic or local anti-inflammatory agents and synovectomy is chosen in some cases. However, the results are not satisfactory and recurrence is common. In this case report, we presented a case of RA with severe shoulder pain, restricted movement due to synovial hypertrophy, and pannus formation which are resistant to local and systemic interventions and not suitable for surgical or chemical synovectomy. Microwave ablation (MWA) was performed successfully without any complication and she well responded in terms of DAS-28, functional, and pain scores. Range of motion and funcitonal restriction were recovered. This case report describes the use and promising results of MWA in RA with severe synovial hypertrophy and pannus formation even in the absence of active arthritis and effusion. MWA is a safe and minimally invasive technique that can be easily performed in coordinance of rheumatologists and interventional radiologists in proper cases.

Percutaneous Ablation of T1b Renal Cell Carcinoma: An Overview

PURPOSE OF REVIEW

There is increasing incidence of renal cell carcinoma (RCC) with multiple treatment options currently available. The purpose of this review is to outline patient selection and technical approaches and present the current literature for percutaneous ablation of T1b (4.1-7 cm) RCC.

RECENT FINDINGS

An increasing number of retrospective studies and meta-analyses have evaluated the use of percutaneous ablation for T1b RCC. Overall, these studies tend to show that percutaneous ablation in this patient population is feasible. However, rates of major adverse events and local recurrence after percutaneous ablation for T1b RCC are both higher than when ablation is used for smaller tumors. As such, a multi-disciplinary, patient-centered approach is required. Due to the increasing literature in this area, the most recent National Comprehensive Cancer Network (NCCN) guidelines include percutaneous ablation as an option for non-surgical patients with T1b RCC.

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.

Minimally invasive transperitoneal partial versus radical nephrectomy in obese patients: perioperative and long-term functional outcomes from a large perspective contemporary series (RECORd2 project)

BACKGROUND

The aim of this study is to evaluate the perioperative and long-term functional outcomes of laparoscopic (LPN) and robot-assisted partial nephrectomy (RAPN) in comparison to laparoscopic radical nephrectomy (LRN) in obese patients diagnosed with renal cell carcinoma.

METHODS

Clinical data of 4325 consecutive patients from The Italian REgistry of COnservative and Radical Surgery for cortical renal tumor Disease (RECORD 2 Project) were gathered. Only patients treated with transperitoneal LPN, RAPN, or LRN with Body Mass Index (BMI) ≥30 kg/m2, clinical T1 renal tumor and preoperative estimated glomerular filtration rate (eGFR) ≥60 mL/min, were included. Perioperative, and long-term functional outcomes were examined.

RESULTS

Overall, 388 patients were included, of these 123 (31.7%), 120 (30.9%) and 145 (37.4%) patients were treated with LRN, LPN, and RAPN, respectively. No significant difference was observed in preoperative characteristics. Overall, intra and postoperative complication rates were comparable among the groups. The LRN group had a significantly increased occurrence of acute kidney injury (AKI) compared to LPN and RAPN (40.6% vs. 15.3% vs. 7.6%, P=0.001). Laparoscopic RN showed a statistically significant higher renal function decline at 60-month follow-up assessment compared to LPN and RAPN. A significant renal function loss was recorded in 30.1% of patients treated with LRN compared to 16.7% and 10.3% of patients treated with LPN and RAPN (P=0.01).

CONCLUSIONS

In obese patients, both LPN and RAPN showcased comparable complication rates and higher renal function preservation than LRN. These findings highlighted the potential benefits of minimally invasive PN over radical surgery in the context of obese individuals.

Perioperative and Survival Outcomes of Patients Treated With Robot-Assisted Partial Nephrectomy and Percutaneous Microwave Ablation for Small Renal Masses: A Single Center Experience

BACKGROUND

Robot assisted partial nephrectomy (RAPN) and microwave ablation (MWA) are 2 of the most advanced techniques for the management of localized small renal masses.

PURPOSE

To compare the perioperative, functional and oncological results of RAPN and MWA.

MATERIALS AND METHODS

Data from 171 consecutive patients undergoing either RAPN or MWA for a localized small renal mass at a single academic center was retrospectively collected. Baseline features included patients' demographics and masses' characteristics. Procedures were compared in terms of perioperative outcomes and renal function variation Progression of a persistent lesion or local recurrence after a complete treatment defined local tumor progression. Descriptive statistics and survival analysis tested the association between predictors and local tumor progression.

RESULTS

Of all, 109 and 62 patients underwent RAPN and MWA. Patients in the MWA group were older (P = .002) had higher Charlson Comorbidity Index (CCI) (P < .001) and higher frequency of preoperative chronic kidney disease (P < .001). MWA led to a shorter postoperative hospitalization time (P < .001) and lower incidence of medical complications (6.5% vs. 22.9%, P = .02) than RAPN. GFR decline was similar between groups both at discharge (P = .39) and at the time of last follow up (P = 1.00). A lower rate of secondary interventions (11.7% vs. 2.8%, P = .037) and a better disease-free survival (83.2% vs. 96.5%, P = .027) were reported after RAPN. Conversely, cancer specific and overall survival were comparable (P > .05). At univariate regression analysis, MWA was associated with local tumor progression (HR 3.46, P = .040).

CONCLUSION

MWA displayed a lower perioperative impact, while functional outcomes were similar after each intervention. RAPN resulted superior in terms of tumor eradication, but no difference was noted regarding cancer specific survival. Thus, MWA represents a valid alternative in frail patients, though less radical than RAPN.

Ablative Treatments for Small Renal Masses and Management of Recurrences: A Comprehensive Review

This review focuses on ablative techniques for small renal masses (SRMs), including radiofrequency ablation (RFA), cryoablation (CA), microwave ablation (MWA), and irreversible electroporation (IRE), and discusses recurrence management. Through an extensive literature review, we outline the procedures, outcomes, and follow-up strategies associated with each ablative method. The review provides a detailed examination of these techniques-RFA, CA, MWA, and IRE-elucidating their respective outcomes. Recurrence rates vary among them, with RFA and CA showing comparable rates, MWA demonstrating favorable short-term results, and IRE exhibiting promise in experimental stages. For managing recurrences, various strategies are considered, including active surveillance, re-ablation, or salvage surgery. Surveillance is preferred post-RFA and post-CA, due to slow SRM growth, while re-ablation, particularly with RFA and CA, is deemed feasible without additional complications. Salvage surgery emerges as a viable option for larger or resistant tumors. While ablative techniques offer short-term results comparable to surgery, further research is essential to understand their long-term effects fully. Decisions concerning recurrence management should consider individual and tumor-specific factors. Imaging, notably contrast-enhanced ultrasounds, plays a pivotal role in assessing treatment success, emphasizing the necessity of a multidisciplinary approach for optimal outcomes. The lack of randomized trials highlights the need for further research.

Safety and Diagnostic Efficacy of Image-Guided Biopsy of Small Renal Masses

INTRODUCTION

Image-guided renal mass biopsy is gaining increased diagnostic acceptance, but there are limited data concerning the safety and diagnostic yield of biopsy for small renal masses (≤4 cm). This study evaluated the safety, diagnostic yield, and management after image-guided percutaneous biopsy for small renal masses.

METHODS

A retrospective IRB-approved study was conducted on patients who underwent renal mass biopsy for histopathologic diagnosis at a single center from 2015 to 2021. Patients with a prior history of malignancy or a renal mass >4 cm were excluded. Descriptive statistics were used to summarize patient demographics, tumor size, the imaging modality used for biopsy, procedure details, complications, pathological diagnosis, and post-biopsy management. A biopsy was considered successful when the specimen was sufficient for diagnosis without need for a repeat biopsy. Complications were graded according to the SIR classification of adverse events. A chi-squared test (significance level set at p ≤ 0.05) was used to compare the success rate of biopsies in different lesion size groups.

RESULTS

A total of 167 patients met the inclusion criteria. The median age was 65 years (range: 26-87) and 51% were male. The median renal mass size was 2.6 cm (range: one-four). Ultrasound was solely employed in 60% of procedures, CT in 33%, a combination of US/CT in 6%, and MRI in one case. With on-site cytopathology, the median number of specimens obtained per procedure was four (range: one-nine). The overall complication rate was 5%. Grade A complications were seen in 4% (n = 7), consisting of perinephric hematoma (n = 6) and retroperitoneal hematoma (n = 1). There was one grade B complication (0.5%; pain) and one grade D complication (0.5%; pyelonephritis). There was no patient mortality within 30 days post-biopsy. Biopsy was successful in 88% of cases. A sub-group analysis showed a success rate of 85% in tumors <3 cm and 93% in tumors ≥3 cm (p = 0.01). Pathological diagnoses included renal cell carcinoma (65%), oncocytoma (18%), clear cell papillary renal cell tumors (9%), angiomyolipoma (4%), xanthogranulomatous pyelonephritis (1%), lymphoma (1%), high-grade papillary urothelial carcinoma (1%), and metanephric adenoma (1%), revealing benign diagnosis in 30% of cases. The most common treatment was surgery (40%), followed by percutaneous cryoablation (22%). In total, 37% of patients were managed conservatively, and one patient received chemotherapy.

CONCLUSION

This study demonstrates the safety and diagnostic efficacy of image-guided biopsy of small renal masses. The diagnostic yield was significantly higher for masses 3-4 cm in size compared to those <3 cm. The biopsy results showed a high percentage of benign diagnoses and informed treatment decisions in most patients.

How many cases are required to achieving early proficiency in purely off-clamp robot-assisted partial nephrectomy?

Background and purpose

Off-clamp robot-assisted partial nephrectomy (Offc-RAPN) is a technically challenging procedure that can effectively avoid renal ischemia owing to the absence of hilar vessel preparation and clamping. However, data on the learning curve (LC) for this technique are limited. The purpose of this study was to assess the LC of Offc-RAPN and compare the perioperative outcomes between different learning phases.

Methods

This retrospective study included 50 consecutive patients who underwent purely Offc-RAPN between January 2022 and April 2023. Multidimensional cumulative sum (CUSUM) analysis method was used to assess LC. Spearman's correlation and LOWESS analysis were performed to analyze the continuous variables of perioperative outcomes. Baseline characteristics and perioperative outcomes were compared using χ2-test, t-test and U-test.

Results

CUSUM analysis identified two LC phases: phase I (the first 24 cases) and phase II (the subsequent 26 cases). Phase II showed significant reductions in mean operative time (133.5 vs. 115.31 min; p = 0.04), mean console time (103.21 vs. 81.27 min; p = 0.01), and mean postoperative length of stay (5.33 vs. 4.30 days; p = 0.04) compared to phase I. However, no significant differences were observed in other perioperative outcomes or baseline characteristics between the two LC phases.

Conclusions

Offc-RAPN performed by a surgeon with experience in laparoscopic and robotic surgeries achieved early proficiency in 24 cases. Moreover, Offc-RAPN alone is safe and feasible even in the initial phase of the LC for an experienced surgeon.

Technical and Clinical Outcomes of Laparoscopic-Laparotomic Hepatocellular Carcinoma Thermal Ablation with Microwave Technology: Case Series and Review of Literature

PURPOSE

To evaluate technical and clinical outcomes of intraoperative (laparoscopic/laparotomic) microwave ablation on HCC.

MATERIALS AND METHODS

This is a retrospective single-center study evaluating consecutive patients treated for very early/early-stage HCC with intraoperative microwave ablation from 1 July 2017 to 30 June 2023. In these patients, a percutaneous US-guided approach was excluded due to the nodule's suboptimal visibility or harmful location and liver resection for a deep position or adherences. Data about the clinical stage, surgical approach, liver pathology and nodules characteristics, technical success, complications, and follow-up were collected. Technical success was intended as the absence of locoregional persistence at follow-up CT/MRI controls.

RESULTS

A total of 36 cirrhotic patients (M:F = 30:6, median age 67 years) were enrolled; 18/36 (50%) had a single nodule, 13/36 (36%) had two, 4/36 had three (11%), and 1/36 had four (3%). Among the patients, 24 (67%) were treated with laparoscopy, and 12/36 (33%) with a laparotomic approach. Sixty HCCs of 16.5 mm (6-50 mm) were treated for 7 min (2-30 min) with 100 W of power. A total of 55 nodules (92%) were treated successfully and showed no residual enhancement at the first postoperative follow-up; the other 5/60 (8%) underwent chemo/radioembolization. There was one complication (3%): a biliary fistula treated with percutaneous drainage and glue embolization. The average hospital stay was 3.5 days (1-51 days), and patients were followed up on average for 238 days (13-1792 days). During follow-up, 5/36 patients (14%) underwent liver transplantation, 1/36 (2%) died during hospitalization and 1 after discharge.

CONCLUSIONS

Laparoscopic/laparotomic intraoperative HCC MW ablation is feasible in patients unsuitable for percutaneous approach or hepatic resection, with rare complications and with good technical and clinical outcomes.

Role of Renal Biopsy in the Management of Renal Cancer: Concordance between Ultrasound/CT-Guided Biopsy Results and Definitive Pathology, Adverse Events, and Complication Rate

(1) Background: In the last decade, the number of detected renal cancer cases has increased, with the highest incidence in Western countries. Although renal biopsy is reported as a safe procedure, it is not adopted in all centres. As it is not possible to accurately distinguish benign tumours using imaging, this may lead to overtreatment. Most of the cancer detected on imaging is treated by surgery, radiofrequency ablation (RFA), or cryotherapy. (2) Methods: This was a single-centre retrospective study of 225 patients studied preoperatively with ultrasound (US)/CT-guided renal biopsy, with the aim of supporting clinical management. Decisions regarding the biopsy were based on either MDT indication or physician preference. US-guided renal biopsy was the first option for all patients; CT-guided biopsy was used when US-guided biopsy was not feasible. The efficacy of renal biopsy in terms of diagnostic performance and the concordance between biopsy results and definitive pathology were investigated. Additionally, adverse events related to the biopsy were recorded and analysed. Data collected throughout the study were analysed using binary logistic regression, Fisher's exact test, and Pearson's chi-square test to investigate possible correlations between post-procedural complications and the size of the lesion. (3) Results: Renal biopsy was not diagnostic in 23/225 (10.2%) patients. A CT-guided approach was necessary in 20/225 patients after failure of US-guided biopsy. The complication rate of renal biopsy was 4.8% overall-all Clavien grade I and without any serious sequelae. Interestingly, complications occurred in patients with very different sizes of renal cell carcinoma. No correlation between complications and anticoagulant/antiplatelet drugs was found. No seeding was reported among the patients who underwent partial/radical nephrectomy. (4) Conclusions: Renal biopsy was shown to be safe and effective, with a high concordance between biopsy results and definitive pathology and a low rate of complications. The use of a CT-guided approach whenever the US-guided approach failed improved the diagnostic performance of renal biopsy.

Advancements in Microwave Ablation Techniques for Managing Pancreatic Lesions

Thermal ablation, including microwave ablation, has become increasingly important in the management of many solid tumors, including primary and metastatic tumors of the liver, kidney, and lung. However, its adoption to treat pancreatic lesions has been slowed due to concerns about potential adverse events. The success of radiofrequency ablation (RFA) in inoperable pancreatic cancers paved the way for its use in pancreatic neuroendocrine tumors and pancreatic cystic neoplasms (PCLs). In the last decade, other thermal ablation techniques, like microwave ablation, have emerged as alternatives to RFA. Microwaves, with frequencies ranging from 900 to 2450 MHz, generate heat by rapidly oscillating water molecules. Microwave ablation's advantage lies in its ability to achieve higher intra-lesion temperatures and uniform heating compared with RFA. Microwave ablation's application in pancreatic cancer and pancreatic neuroendocrine tumors has demonstrated promise with similar technical success to RFA. Yet, concern for peri-procedure complications, as well as a dearth of studies comparing RFA and microwave ablation, emphasize the need for further research. No studies have evaluated microwave ablation in PCLs. We herein review thermal ablation's potential to treat pancreatic lesions.

A systematic review of robot-assisted partial nephrectomy outcomes for advanced indications: Large tumors (cT2-T3), solitary kidney, completely endophytic, hilar, recurrent, and multiple renal tumors

Objective

Robot-assisted partial nephrectomy (RAPN) has become widely used for treatment of renal cell carcinoma and it is expanding in the field of complex renal masses. The aim of this systematic review was to analyze outcomes of RAPN for completely endophytic renal masses, large tumors (cT2-T3), renal cell carcinoma in solitary kidney, recurrent tumors, completely endophytic and hilar masses, and simultaneous and multiple tumors.

Methods

A comprehensive search in the PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases was performed in December 2022 for English language papers. The primary endpoint was to evaluate the role of RAPN in the setting of each category of complex renal masses considered. The secondary endpoint was to evaluate the surgical and functional outcomes.

Results

After screening 1250 records, 43 full-text manuscripts were selected, comprising over 8500 patients. Twelve and thirteen studies reported data for endophytic and hilar renal masses, respectively. Five and three studies reported outcomes for cT2-T3 and solitary kidney patients, respectively. Four studies focused on redo-RAPN for recurrent tumors. Two studies investigated simultaneous bilateral renal masses and five reports focused on multiple tumor excision in ipsilateral kidney.

Conclusion

Over the past decade, evidence supporting the use of RAPN for the most challenging nephron-sparing surgery indications has continuously grown. Although limitations remain including study design and lack of detailed long-term functional and oncological outcomes, the adoption of RAPN for the included advanced indications is associated with favorable surgical outcomes with good preservation of renal function without compromising the oncological result. Certainly, a higher likelihood of complication might be expected when facing extremely challenging cases. However, none of these indications should be considered per se an exclusion criterion for performing RAPN. Ultimately, a risk-adapted approach should be employed.

Small Renal Masses: Developing a Robust Radiomic Signature

(1) Background and (2) Methods: In this retrospective, observational, monocentric study, we selected a cohort of eighty-five patients (age range 38-87 years old, 51 men), enrolled between January 2014 and December 2020, with a newly diagnosed renal mass smaller than 4 cm (SRM) that later underwent nephrectomy surgery (partial or total) or tumorectomy with an associated histopatological study of the lesion. The radiomic features (RFs) of eighty-five SRMs were extracted from abdominal CTs bought in the portal venous phase using three different CT scanners. Lesions were manually segmented by an abdominal radiologist. Image analysis was performed with the Pyradiomic library of 3D-Slicer. A total of 108 RFs were included for each volume. A machine learning model based on radiomic features was developed to distinguish between benign and malignant small renal masses. The pipeline included redundant RFs elimination, RFs standardization, dataset balancing, exclusion of non-reproducible RFs, feature selection (FS), model training, model tuning and validation of unseen data. (3) Results: The study population was composed of fifty-one RCCs and thirty-four benign lesions (twenty-five oncocytomas, seven lipid-poor angiomyolipomas and two renal leiomyomas). The final radiomic signature included 10 RFs. The average performance of the model on unseen data was 0.79 ± 0.12 for ROC-AUC, 0.73 ± 0.12 for accuracy, 0.78 ± 0.19 for sensitivity and 0.63 ± 0.15 for specificity. (4) Conclusions: Using a robust pipeline, we found that the developed RFs signature is capable of distinguishing RCCs from benign renal tumors.

Urinary MicroRNAs as Biomarkers of Urological Cancers: A Systematic Review

MicroRNAs (miRNAs) are emerging as biomarkers for the detection and prognosis of cancers due to their inherent stability and resilience. To summarize the evidence regarding the role of urinary miRNAs (umiRNAs) in the detection, prognosis, and therapy of genitourinary cancers, we performed a systematic review of the most important scientific databases using the following keywords: (urinary miRNA) AND (prostate cancer); (urinary miRNA) AND (bladder cancer); (urinary miRNA) AND (renal cancer); (urinary miRNA) AND (testicular cancer); (urinary miRNA) AND (urothelial cancer). Of all, 1364 articles were screened. Only original studies in the English language on human specimens were considered for inclusion in our systematic review. Thus, a convenient sample of 60 original articles was identified. UmiRNAs are up- or downregulated in prostate cancer and may serve as potential non-invasive molecular biomarkers. Several umiRNAs have been identified as diagnostic biomarkers of urothelial carcinoma and bladder cancer (BC), allowing us to discriminate malignant from nonmalignant forms of hematuria. UmiRNAs could serve as therapeutic targets or recurrence markers of non-muscle-invasive BC and could predict the aggressivity and prognosis of muscle-invasive BC. In renal cell carcinoma, miRNAs have been identified as predictors of tumor detection, aggressiveness, and progression to metastasis. UmiRNAs could play an important role in the diagnosis, prognosis, and therapy of urological cancers.

Focal Cryo-Immunotherapy with Intratumoral IL-12 Prevents Recurrence of Large Murine Tumors

Focal ablation technologies are routinely used in the clinical management of inoperable solid tumors but they often result in incomplete ablations leading to high recurrence rates. Adjuvant therapies, capable of safely eliminating residual tumor cells, are therefore of great clinical interest. Interleukin-12 (IL-12) is a potent antitumor cytokine that can be localized intratumorally through coformulation with viscous biopolymers, including chitosan (CS) solutions. The objective of this research was to determine if localized immunotherapy with a CS/IL-12 formulation could prevent tumor recurrence after cryoablation (CA). Tumor recurrence and overall survival rates were assessed. Systemic immunity was evaluated in spontaneously metastatic and bilateral tumor models. Temporal bulk RNA sequencing was performed on tumor and draining lymph node (dLN) samples. In multiple murine tumor models, the addition of CS/IL-12 to CA reduced recurrence rates by 30-55%. Altogether, this cryo-immunotherapy induced complete durable regression of large tumors in 80-100% of treated animals. Additionally, CS/IL-12 prevented lung metastases when delivered as a neoadjuvant to CA. However, CA plus CS/IL-12 had minimal antitumor activity against established, untreated abscopal tumors. Adjuvant anti-PD-1 therapy delayed the growth of abscopal tumors. Transcriptome analyses revealed early immunological changes in the dLN, followed by a significant increase in gene expression associated with immune suppression and regulation. Cryo-immunotherapy with localized CS/IL-12 reduces recurrences and enhances the elimination of large primary tumors. This focal combination therapy also induces significant but limited systemic antitumor immunity.

Ultrasound-Guided Percutaneous Thermal Ablation of Renal Cancers-In Search for the Ideal Tumour

Over the recent years, the 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 success of percutaneous radiofrequency ablation (RFA) in relation to kidney tumour diameter and location. Between August 2016 and September 2021, 253 patients with 259 renal tumours underwent US-guided RFA as a primary treatment in our institution. A total of 67 patients were excluded from this study. Abdominal computed tomography (CT) and tumour biopsy were performed before the procedure. Patients were followed with contrast-enhanced CT, the average follow-up time was 28 months. The studied group was composed of 186 patients with 191 renal tumours-only biopsy-confirmed renal cancers were included. During the follow-up, 46 cases of residual disease and 4 cases of local progression were found. There was a significant correlation between tumour size and the ablation success rate. The success rate was 73.5% and 87.6% for lesions ≤25 mm, 94.6% for lesions ≤25 mm and exophytic, 79.1% for lesions 26-30 mm and 84.4% for lesions 26-30 mm and exophytic, respectively. Four Clavien-Dindo grade ≥2 complications were observed. US-guided percutaneous RFA of T1a renal cancers is safe and well-tolerated. Its effectiveness depends on tumour size, with best results for exophytic lesions smaller than 3 cm. Most of the recurrent or residual tumours can be successfully re-treated with US-guided percutaneous RFA.

Navigating the Current Landscape of Non-Clear Cell Renal Cell Carcinoma: A Review of the Literature

Non-clear cell renal cell carcinoma (nccRCC) is an entity comprised of a heterogeneous constellation of RCC subtypes. Genomic profiling has broadened our understanding of molecular pathogenic mechanisms unique to individual nccRCC subtypes. To date, clinical trials evaluating the use of immunotherapies and targeted therapies have predominantly been conducted in patients with clear cell histology. A comprehensive review of the literature has been undertaken in order to describe molecular pathogenic mechanisms pertaining to each nccRCC subtype, and concisely summarise findings from therapeutic trials conducted in the nccRCC space.

Renal Cell Carcinoma as a Metabolic Disease: An Update on Main Pathways, Potential Biomarkers, and Therapeutic Targets

Clear cell renal cell carcinoma (ccRCC) is the most frequent histological kidney cancer subtype. Over the last decade, significant progress has been made in identifying the genetic and metabolic alterations driving ccRCC development. In particular, an integrated approach using transcriptomics, metabolomics, and lipidomics has led to a better understanding of ccRCC as a metabolic disease. The metabolic profiling of this cancer could help define and predict its behavior in terms of aggressiveness, prognosis, and therapeutic responsiveness, and would be an innovative strategy for choosing the optimal therapy for a specific patient. This review article describes the current state-of-the-art in research on ccRCC metabolic pathways and potential therapeutic applications. In addition, the clinical implication of pharmacometabolomic intervention is analyzed, which represents a new field for novel stage-related and patient-tailored strategies according to the specific susceptibility to new classes of drugs.