Laparoscopic vs Percutaneous Cryoablation for the Small Renal Mass: 15-Year Experience at a Single Center

Intraoperative MRI-derived volumetric ablation margins and initial correlation with local outcome after MRI-guided cryoablation of renal tumors

PURPOSE

To assess volumetric ablation margins derived from intraoperative pre- and post-ablation MRI after magnetic resonance imaging (MRI)-guided percutaneous cryoablation of renal tumors and explore its correlation with local treatment success.

METHODS

Retrospective analysis was performed on 30 patients (mean age 69y) who underwent percutaneous MRI-guided cryoablation between May 2014 and May 2020 for 32 renal tumors (size: 1.6-5.1 cm). Tumor and ice-ball volumes were segmented on intraprocedural pre- and post-ablation MR images using Software Assistant for Interventional Radiology (SAFIR) software. After MRI-MRI co-registration, the software automatically quantified the minimal treatment margin (MTM),defined as the smallest 3D distance between the tumor and ice-ball surface. Local tumor progression (LTP) after cryoablation was assessed on follow-up imaging.

RESULTS

Median follow-up was 16 months (range: 1-58). Local control after cryoablation was achieved in 26 cases (81%) while LTP occurred in 6 (19%). The intended MTM of ≥5 mm was achieved in 3/32 (9%) cases. Median MTM was significantly smaller for cases with (- 7 mm; IQR:-10 to - 5) vs. without LTP (3 mm; IQR:2 to 4) (P < .001). All cases of LTP had a negative MTM. All negative treatment margins occurred in tumors > 3 cm.

CONCLUSIONS

Determination of volumetric ablation margins from intraoperative MRI was feasible and may be useful in predicting local outcome after MRI-guided renal cryoablation. In our preliminary data, an intraoperative MRI-derived minimal margin extending at least 1 mm beyond the MRI-visible tumor led to local control and this was more difficult to achieve in tumors > 3 cm. Ultimately, online margin analysis may be a valuable tool to intraoperatively assess therapy success, but larger prospective studies are needed to establish a reliable threshold for clinical use.

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

BACKGROUND

Ablative techniques emerged as effective alternative to nephron-sparing surgery for treatment of small renal masses. Radiofrequency ablation (RFA) and cryoablation (CRYO) are the two guidelines-recommended techniques. Microwave ablation (MWA) represents a newer technology, less described. The aim of the study was to compare outcomes of MWA to those of CRYO and RFA.

METHODS

Retrospective investigation of patients who underwent MWA, CRYO, or RFA from seven high-volume US and European centers was performed. The first group included patients who underwent CRYO or RFA; the second MWA. We collected baseline characteristics, clinical, intraoperative, and postoperative data. Oncological data included technical success, local recurrence, and progression to metastasis. Multivariate analysis was performed to find predictors for postoperative complications. A composite outcome of "trifecta" was used to assess surgical, functional, and oncological outcomes.

RESULTS

739 patients underwent CRYO or RFA and 50 MWA. CRYO/RFA group had significantly longer operative time (P<0.001), but no difference in LOS, postprocedural Hb mean, intraprocedural complications (P=0.180), overall postprocedural complication rates (P=0.126), and in the 30-day re-admission rate (P=0.853) were detected. No predictive parameter of postprocedural complications was found. Concerning functional outcome, no differences were detected in terms of eGFR at 1 year (P=0.182), ΔeGFR at 1 year (P=0.825) and eGFR at latest follow-up (P=0.070). "Technical success" was achieved in 98.6% of the cases (MWA=100%, CRYO/RFA=98.5%; P=0.775), and there was no significant difference in terms of 2-year recurrence rate (P=0.114) and metastatic progression (P=0.203). Trifecta was achieved in 73.0% of CRYO/RFA vs. 69.6% of MWA cases (P=0.719).

CONCLUSIONS

MWA is a safe and effective treatment option for small renal masses. Compared with CRYO/RFA, it seems to offer low complication rates, shorter operation time, and equivalent surgical and functional outcomes.

Percutaneous thermal ablation for cT1 renal mass in solitary kidney: A multicenter trifecta comparative analysis versus robot-assisted partial nephrectomy

INTRODUCTION

Renal cell carcinoma (RCC) in solitary kidney (SK) represents a challenging scenario. We sought to compare outcomes of robot-assisted partial nephrectomy (RAPN) versus percutaneous thermal ablation (PTA) in SK patients with renal tumors cT1.

MATERIALS AND METHODS

We performed a multicenter retrospective analysis of SK patients treated for RCC. The PTA group included cryoablation or radiofrequency ablation. We collected baseline characteristics, intraoperative, pathological, and post-operative data. We applied an arbitrary composite "trifecta" to assess surgical, functional, and oncological outcomes, only for malignant histology. RFS analysis was performed using the Kaplan-Meier method. Multivariable regression analysis was performed to determine independent predictors of "trifecta" achievement.

RESULTS

We included 198 SK patients (RAPN, n = 50; PTA n = 119). Mean clinical tumor size was not significantly different while R.E.N.A.L. score was higher for RAPN (p < 0.001). No differences in intra and major post-procedural complications. Recurrence rate was higher in PTA group but not statistically significant (p < 0.328). No difference in metastasis rate was found (p = 0.435). RFS was 96.1% in RAPN and 86.8% in PTA cohort (p = 0.003) while no difference in PFS was detected (p = 0.1). Trifecta was achieved in 72.5% of RAPN vs 77.3% of PTA (p = 0.481). Multivariable analysis has not detected predictors for Trifecta achievement.

CONCLUSION

PTA offers good outcomes in the management of SK patients with RCC. Compared with RAPN, it might carry a higher risk of recurrence; on the other hand, re-treatment is possible. Overall, PTA can be safely offered to treat SK patients presenting RCC. In general, it should be preferred in more frail patients to minimize the risk of complications.

Long-term outcomes of cryoablation for biopsy-proven T1 stage renal cell carcinoma

Background

To summarize our clinical experience of cryoablation in renal cell carcinoma (RCC) of Chinese population and to evaluate the long-term outcomes of laparoendoscopic single-site (LESS) cryoablation (LCA) as well as percutaneous CT-guided cryoablation (PCA) for biopsy-proven T1a and T1b RCC.

Methods

This was a multi-center, retrospective study investigating T1 stage RCC patients from 2011 to 2021. The patients were treated by LCA or PCA according to individual situation. Overall survival (OS), cancer-related survival (CSS), and progression-free survival (PFS) were evaluated for oncological outcomes, and kidney function, complications, and hospital stay were used to estimate technical outcomes.

Results

A total of 163 consecutive patients were included. Among them, 59 cases were treated by LCA and PCA was performed in 104 cases. All operations were processed successfully. Mean diameter of the mass was (2.9±1.4) cm; median blood volume was 45ml (10~200 ml). The mean operation time was 84.0 ± 24.5 min. The median postoperative hospital stay was 3 days (1~6 days). Compared with LCA, procedure time of PCA was shortened, the volume of bleeding was reduced, and the hospital stay was decreased. The overall adverse events rate was 9.8% (16/163). The mean preoperative and postoperative eGFR of LCA were 77.6±15.3 ml/min and 75.6±17.4 ml/min, respectively. Analogously, the values of PCA were 78.7±12.9 ml/min and 76.7±14.3 ml/min. Mean follow-up time was 64.2 ± 30.2 months (range, 7–127 months). Local recurrence was observed in 13 patients (8.0%), 4 (6.8%) cases of LCA and 9 (8.7%) cases of PCA. PFS at 5 and 10 years were 95.5% and 69.2% for LCA and 96.7% and 62.8% for PCA. In total, 26 patients (16.0%) (11 patients from LCA and 15 from PCA) died throughout the follow-up period. OS at 5 and 10 years were 93.8% and 31.4% for LCA, and 97.4% and 52.7% for PCA. Six patients (3.7%) (3 cases from LCA and 3 from PCA) died of metastatic RCC. CCS for LCA were 98.0% and 82.8% at 5 and 10 years, while the data were 100% and 86.4% for PCA.

Conclusion

LCA and PCA for T1 stage RCC provides satisfactory long-term oncological and renal function preservation outcomes, with acceptable complication rates.

Assessing Trifecta Achievement after Percutaneous Cryoablation of Small Renal Masses: Results from a Multi-Institutional Collaboration

Background and Objectives: To assess efficacy and safety of Percutaneous Cryoablation (PCA) of small renal masses (SRMs) using Trifecta outcomes in a large cohort of patients who were not eligible for surgery. Materials and methods: All PCAs performed in four different centers between September 2009 and September 2019 were retrospectively evaluated. Patients were divided in two different groups depending on masses dimensional criteria: Group-A: diameter ≤ 25 mm and Group-B: diameter > 25 mm. Complications rates were reported and classified according to the Clavien−Dindo system. The estimate glomerular filtration rate (eGFR) was calculated before PCA and during follow-up schedule. Every patient received a Contrast Enhanced Ultrasound (CEUS) evaluation on the first postoperative day. Radiological follow-up was taken at 3, 6, and 12 months for the first year, then yearly. Radiological recurrence was defined as a contrast enhancement persistence and was reported in the study. Finally, Trifecta outcome, which included complications, RFS, and preservation of eGFR class, was calculated for every procedure at a median follow-up of 32 months. Results: The median age of the patients was 74 years. Group-A included 200 procedures while Group-B included 140. Seventy-eight patients were eligible for Trifecta evaluation. Trifecta was achieved in 69.6% of procedures in Group-A, 40.6% in Group-B (p = 0.02). We observed an increased rate of complication in Group-B (13.0% vs. 28.6; p < 0.001). However, 97.5% were <II Clavien−Dindo grade. No differences were found between the two groups regarding eGFR before and after treatment. Further, 24-months RFS rates were respectively 98.0% for Group-A and 92.1% in Group-B, while at 36 months were respectively 94.5% and 87.5% (p = 0.08). Conclusions: PCA seems to be a safe and effective treatment for SRM but in the need of more strict dimensional criteria to achieve a higher possible success rate.

Comparison of Radiofrequency Ablation Versus Cryoablation For T1 Renal Tumors: An Evidence-Based Analysis of Comparative Outcomes

Objective

To discuss the differences in the effectiveness and security for T1 renal tumors by radiofrequency ablation (RFA) and cryoablation (CA).

Methods

We systematically searched the Cochrane Library, PubMed, Embase, CNKI databases, and Science databases, and the date was from the above database establishment to August 2021. Controlled trials on RFA and CA for T1 renal tumors were included. The meta-analysis was conducted with the Review Manager 5.4 software.

Results

A total of ten studies with 2,367 patients were included in the analysis. There were no significant differences in complications (odds ratio [OR], 1.23; 95% CI, 0.80 to 1.90; p=0.35), primary technique efficacy rate (OR, 1.01; 95% CI, 0.33 to 3.14; p=0.98), changes in serum creatinine (weighted mean difference [WMD], 0.53; 95% CI, -0.50 to 1.57; p=0.31), or 5-year survival rate (hazard ratio [HR], 1.11; 95% CI, 0.41 to 3.00; p=0.84) among patients undergoing RFA and CA. However, compared with patients who underwent RFA, patients who underwent CA had a lower Local recurrence (OR: 2.25; 95% CI: 1.38 to 3.67; p = 0.001).

Conclusion

The analysis demonstrated that in the treatment of T1 renal tumors, CA may be associated with lower local recurrence rates. However, no differences were observed in terms of primary technique efficacy rate, 5-year survival rate, changes in serum creatinine, and complication rate between groups.

Systematic Review Registration

[https://www.crd.york.ac.uk/PROSPERO/], identifier PROSPERO (CRD42021295160).

Cryoablation of renal tumors: long-term follow-up from a multicenter experience

Purpose

To retrospectively investigate long-term outcomes of renal cryoablation from a multicenter database.

Methods

338 patients with 363 renal tumors underwent cryoablation in 4 centers in North-Eastern Italy. 340/363 tumors (93.7%) were percutaneously treated with CT guidance. 234 (68.8%) were treated after conscious sedation, 76 (22.3%) under local lidocaine anesthesia only and 30 (8.8%) under general anesthesia. Treatment efficacy and complication rate considered all procedures. Oncologic outcomes considered a subset of 159 patients with 159 biopsy proven renal cell carcinoma.

Results

Mean tumor size was 2.53 cm. Technical success was achieved in 355/363 (97.8%) treatments. Treatment efficacy after the first treatment was achieved in 348/363 (95.9%) tumors. Statistical analysis revealed a significant lower treatment efficacy for ASA score >3, Padua score >8, tumor size >2.5 cm, use of >2 cryoprobes, presence of one single kidney. In the subset of 159 patients, recurrence-free survival rates were 90.5% (95% CI 83.0%, 94.9%) at 3 years and 82.4% (95% CI 72.0%, 89.4%) at 5 years; overall survival rates were 96.0% (95% CI 90.6%, 98.3%) at 3 years and 91.0% (95% CI 81.7%, 95.7%) at 5 years; no patient in this subset developed metastatic disease. Clavien-Dindo >1 complications were recorded in 14/369 procedures (3.8%) and were related to age >70 years, tumor size >4 cm and use of >2 cryoprobes.

Conclusion

Cryoablation performed across four different centers in a large cohort of predominantly small renal tumors showed that this technique provides good recurrence-free survival rates and overall survival rates at three- and five-year with very low major complications rate.

Electronic supplementary material

The online version of this article (10.1007/s00261-021-03082-z) contains supplementary material, which is available to authorized users.

CT evaluation of patent artery after percutaneous cryoablation of renal cell carcinoma

PURPOSE

The purpose of this retrospective study was to determine the incidence of persistent patent artery after percutaneous cryoablation of renal cell carcinoma (RCC) and the relationship between patent arteries one month after cryoablation and early tumor progression.

MATERIALS AND METHODS

One hundred and fifty-nine patients (112 men, 47 women; mean age, 63.6±14.6 [SD] years; age range: 21-91 years) who underwent percutaneous cryoablation for 186 RCCs (mean diameter, 1.9±0.6 [SD] cm; range: 0.7-4.0cm) were retrospectively included. After cryoablation, patients underwent contrast-enhanced computed tomography (CT) with ≤2-mm slice thickness within one week from cryoablation, and at one, three, and six months. The time course of patent artery in the ablated renal parenchyma after cryoablation was the primary endpoint. The relationships between patent arteries one month after cryoablation and treatment effectiveness, tumor vascularity, tumor enhancement one month after cryoablation, tumor subtype, and renal function changes were evaluated as secondary endpoints.

RESULTS

CT showed patent arteries in the ablated renal parenchyma within one week in 166 RCCs (89.2%), at one month in 54 RCCs (29.0%), at three months in 8 RCCs (4.3%), and at six months in 2 RCCs (1.1%). The presence of patent artery one month after cryoablation was significantly associated with tumor enhancement at the same time point (P=0.015). There was no association between patent arteries one month after cryoablation and treatment effectiveness (P=0.693).

CONCLUSION

Patent arteries in the ablated renal parenchyma are commonly observed on CT examination after percutaneous cryoablation of RCC. However, they gradually disappear and do not require specific treatment.

Percutaneous CT-Guided Renal Cryoablation: Technical Aspects, Safety, and Long-Term Oncological Outcomes in a Single Center

Background and objectives: Cryoablation is emerging as a safe and effective therapeutic option for treating renal cell carcinoma. This study analyzed the safety and long-term oncological outcomes of cryoablation in our center. Materials and methods: Patients who underwent computed tomography (CT)-guided percutaneous cryoablation between February 2011 and June 2020 for one or more clinically localized renal tumors were identified. Technical success and treatment efficacy were assessed. Post-procedural complications were classified according to the Clavien-Dindo system. Recurrence-free survival was determined for biopsy-proven malignant renal tumors. Results: A total of 174 renal tumors, 78 of which were biopsy-proven malignant carcinomas, were treated in 138 patients (97 males and 41 females, mean age: 73 years, range: 43-89 years). Mean tumor size was 2.25 cm and 54.6% of the lesions required a complex approach. Technical success was achieved in 171 out of 174 tumors (98.3%). Primary treatment efficacy was 95.3% and increased to 98.2% when retreats were taken into account. The overall complication rate was 29.8%. No complications of Clavien-Dindo grade III or more were encountered. Median follow-up was 21.92 months (range: 0.02-99.87). Recurrence-free survival was 100% at 1 year, 95.3% (95% CI: 82.1%-98.8%) at 3 years, and 88.6% (95% CI: 71.8%-95.7%) at 5 years. Conclusions: Cryoablation is a safe and effective technique for the treatment of small renal lesions, with no major complications when performed by expert interventional radiologists. The multidisciplinary discussion is essential, especially considering the high number of histologically undetermined lesions. Our long-term oncological outcomes are encouraging and in line with the literature.

Safety and Oncologic Outcomes of Magnetic Resonance Imaging-Guided Cryoablation of Renal Cell Carcinoma: A 10-Year Single-Center Experience

OBJECTIVES

Magnetic resonance imaging guidance has been sporadically reported for renal tumor cryoablation (CA); therefore, clinical experience with this modality is still limited.The aim of this study is to retrospectively analyze our 10-year experience with renal tumor CA performed on a 1.5 T magnetic resonance imaging unit with the intent of reporting procedural safety and oncologic outcomes.

MATERIALS AND METHODS

We included 143 patients (102 men; 41 women; median age, 73 years; range, 34-91 years) with 149 tumors (median size, 2.6 cm; range, 0.6-6.0 cm), treated between 2009 and 2019. Patient, tumor, procedure, and follow-up data were collected and analyzed. The Kaplan-Meier method was used to estimate local recurrence-free (LRFS), metastasis-free (MFS), disease-free (DFS), cancer-specific, and overall (OS) survival. Univariate and multivariate models were used to identify factors associated with complications, LRFS, MFS, DFS, and OS.

RESULTS

The overall complication rate was 10.7% (16/149 tumors), with 1 major (1/149 [0.7%]; 95% confidence interval, 0.0%-3.7%) hemorrhagic complication. Other minor complications (15/149 [10.1%]; 95% confidence interval, 0.6%-16.1%) did not include any cases of injury to nearby organs. There were no factors associated with complications.Five-year estimates of LRFS (primary/secondary), MFS, DFS, cancer-specific survival, and OS were 82.8%/91.5%, 91.1%, 75.1%, 98.2%, and 89.6%, respectively. Increasing tumor size (hazard radio [HR], 1.8; P = 0.02) and intraparenchymal tumor location (HR, 5.6; P < 0.01) were associated with lower LRFS; increasing patient's age (HR, 0.5; P = 0.01), high tumor grade (HR, 23.3; P < 0.01) and non-clear-cell/nonpapillary histology (HR, 20.1; P < 0.01) with metastatic disease; and high tumor grade (HR, 3.2; P = 0.04) with lower DFS.

CONCLUSION

Magnetic resonance imaging-guided CA of renal tumors is associated with acceptable morbidity and high survival estimates at 5-year follow-up. Given the absence of complications resulting from injuries to nearby organs, further studies are required to evaluate whether the potential reduced incidence of these adverse events justifies large-scale implementation of this interventional modality.

Laparoscopic cryoablation for small renal masses: Oncological outcomes at 5-year follow-up

Objective: To evaluate the oncological outcome at 5-year follow-up after laparoscopic cryoablation (LCA) for small renal masses (SRMs), as there is an increasing interest in ablative therapy for cT1a renal tumours due to the rising incidence of SRMs, the trend towards minimally invasive nephron-sparing treatments, and the ageing population.

Patients and methods: Between 2004 and 2015, 233 consecutive LCA were performed in 219 patients for SRMs at two referral centres. We only included those patients with ≥5 years of follow-up (n = 165) in a prospectively maintained database. A descriptive analysis was conducted for pre-, peri- and postoperative characteristics. A Kaplan–Meier analysis assessed overall (OS), disease-specific (DSS), and recurrence-free survival (RFS).

Results: The median (interquartile range [IQR]) age of our patient cohort was 68 (60.5–76) years. The median (IQR) body mass index was 26.2 (23.8–29) kg/m², and the median (IQR) Charlson Comorbidity Index score corrected for age was 4 (2.5–6). The median (IQR) tumour diameter was 28 (21–33) mm. In all, 15% developed a complication in the first 30 days after LCA, of which 1% had a major complication (Clavien–Dindo Grade ≥III). The median (IQR) preoperative estimated glomerular filtration rate (eGFR) was 82.5 (65–93.75) mL/min/1.73 m². The median eGFR decreased by 16.4% and 15.2% at the 3-month and 5-year follow-up, respectively. Persistence was found in 1%, local recurrence in 2%, and systemic progression in 4%. The OS, DSS, and RFS were 74%, 96.9% and 95.4%, respectively.

Conclusion: LCA is a safe and effective treatment for SRMs in selected cases and shows good oncological outcomes after 5 years of follow-up, with only 1% developing a major complication.

Renal cryoablation - does deep endophytic ablation affect the renal collecting system?

Objective: To investigate to what extent the urothelium of the renal collecting system is affected when performing deep endophytic cryoablation.Methods: The study was conducted as an in vivo animal model with a total of 15 female pigs. Each animal was subjected to bilateral endophytioc renal cryoablation and randomized to a postoperative follow-up period of either one, two or four weeks. At the end of follow-up all animals had a magnetic resonance imaging (MRI) examination and bilateral nephrectomy was performed. On MRI-imaging the extent of the cryolesions, as well as signs of urinomas or fistulas, were examined. Histopathologic examinations were performed to investigate the effect on the urothelium.Results: All animals tolerated the procedure well without any postoperative complications. MRI examinations found the renal collecting system to be involved in the cryolesions at all three stages of follow-up and revealed no signs of hematomas, urinomas or fistula formations. Epithelial edema was found at all three stages of follow-up while significant parenchymal fibrosis adjacent to the urothelium was most pronounced in the four weeks of follow-up group. The urothelium was significantly affected with luminal hemorrhage as well as hemorrhage in and underneath the urothelium and urothelial dissociation from the underlying renal parenchyma. Despite these impacts on the urothelium, this was found to be intact and vital at all three stages of follow-up, in sharp contrast to the renal parenchyma that underwent fibrotic changes.Conclusions: In this, in vivo non-tumor pig model CA effectively destroyed the renal parenchyma while the impacted renal urothelium remained intact and did not undergo fibrotic changes, nor was urinomas or fistulas observed.

Systematic Review of Contemporary Evidence for the Management of T1 Renal Cell Carcinoma: What IRs Need to Know for Kidney Cancer Tumor Boards

Renal cell carcinoma is a relatively common malignancy, with 60 to 70 thousand cases a year in the United States alone. Increased utilization of cross-sectional imaging has led to an increase in the number of early renal cell cancers seen by the medical establishment. In addition, certain patient populations have an increased risk of developing kidney cancers which may mandate aggressive screening protocols. This article discusses the epidemiology of renal cell cancers; discusses the current management guidelines from multiple specialty societies; discusses some of the surgical and interventional techniques used in the treatment of such lesions; and provides a review of the literature regarding treatments of early-stage renal cell cancers.

Organ-sparing procedures in GU cancer: part 1-organ-sparing procedures in renal and adrenal tumors: a systematic review

PURPOSE

Organ-sparing surgery (OSS) for the kidney and adrenals has emerged as the need for preservation of function is paramount in patients with poor functional reserve. As reports increasingly showed that oncological outcomes were equivalent to radical excision, elective OSS became a viable alternative in patients with otherwise normal reserve. In this review, we summarize the current knowledge of OSS for adrenal and renal tumors.

MATERIALS AND METHODS

PubMed, Web of Science and Cochrane Library Central Search were searched for recently published articles up to December 2017. The following keywords were used; "partial adrenalectomy", "adrenal sparing", "partial nephrectomy", "nephron sparing", "kidney/renal cancer".

RESULTS

Partial adrenalectomy became an attractive alternative to total adrenalectomy avoiding adrenal insufficiency. Both minimally invasive surgery and ablative techniques were increasingly reported for adrenal OSS with adequate residual adrenal function and excellent oncological outcome. Radical nephrectomy remained for many years as the gold standard of treatment for organ-confined renal cell carcinoma. As the need to reduce the impact on renal function, more conservative approaches were utilized. Soon, the non-inferiority of nephron-sparing surgery to that of radical excision became evident and elective partial nephrectomy was gaining ground as the standard of care for small renal masses in patients with normal contralateral kidneys.

CONCLUSIONS

Herein, we present a comprehensive review of the current status of OSS in renal and adrenal tumors.

The Role of Ablation and Minimally Invasive Techniques in the Management of Small Renal Masses

CONTEXT

Nephron-sparing approaches are increasingly recommended for incidental small renal masses. Herein, we review the current literature regarding the safety and efficacy of focal therapy, including percutaneous ablation, for small renal masses.

OBJECTIVE

To summarize the application of ablative therapy in the management of small renal masses.

EVIDENCE ACQUISITION

PubMed and Medline database search was performed to look for findings published since 2000 on focal therapy for small renal masses. After literature review, 64 articles were selected and discussed.

EVIDENCE SYNTHESIS

Radiofrequency ablation and cryotherapy are the most widely used procedures with intermediate-term oncological outcome comparable with surgical series. Cost effectiveness seems excellent and side effects appear acceptable. To date, no randomized trial comparing percutaneous focal therapy with standard surgical approach or active surveillance has been performed.

CONCLUSIONS

Focal ablative therapies are now accepted as effective treatment for small renal tumors. For tumors <3cm, oncological effectiveness of ablative therapies is comparable with that of partial nephrectomy. Percutaneous ablation has fewer complications and a better postoperative profile when compared with minimally invasive partial nephrectomy.

PATIENT SUMMARY

Focal ablative therapies are now accepted as effective treatment for small renal tumors. For tumors <3cm, oncological effectiveness of ablative therapies is comparable with that of partial nephrectomy.

Traitements ablatifs des tumeurs du rein localisées : radiofréquence ou cryothérapie ?

La radiofréquence et la cryothérapie sont les deux principales techniques ablatives et les principales alternatives à la chirurgie pour le traitement des petites masses rénales. Deux méta-analyses ont comparé radiofréquence et cryothérapie, et conclu à leur équivalence en termes de succès, de récidive et de complications. La cryothérapie est plus coûteuse, techniquement plus compliquée (plusieurs ponctions pour plusieurs cryodes, durée de traitement plus longue), et paraît plus adaptée aux tumeurs complexes (centrorénale et/ou au contact de la voie excrétrice). La voie d’abord percutanée est privilégiée par rapport à la laparoscopie pour sa morbidité moindre et un positionnement des aiguilles guidé par l’imagerie qui est plus précis.

Laparoscopic cryoablation vs. percutaneous cryoablation for treatment of small renal masses: a systematic review and meta-analysis

CONTEXT

Laparoscopic cryoablation (LCA) and percutaneous cryoablation(PCA) have been used on patients with small renal masses(SRMs) for many years. However, clinical studies assessing their feasibility and safety have reported contradictory outcomes. This systematic evaluation was performed to obtain comprehensive evidence with regard to the feasibility and safety of PCA compared with LCA.

METHODS

A systematic search of Embase, Pubmed, Medline, the Cochrane Library were performed to identify studies that compared LCA with PCA were published up to Mar 2016. Outcomes of interest included perioperative, pathologic variables, and complications.

RESULTS

Thirteen studies estimating LCA versus PCA were included for meta-analysis. Patients undergoing PCA were significantly older(WMD = -0.16 years; P = 0.01) and patients with posterior tumors were significantly prefer undergoing PCA than LCA(OR = 0.23; P = 0.0007), whereas patients with anterior tumors were significantly prefer undergoing LCA(OR = 3.82; P = 0.02). although PCA was associated with shorter hospital stay(WMD = 1.17 days; P < 0.0001) and higher incidence rate of perirenal hematoma(OR = 0.18; P < 0.0001). All the other analyzed parameters were similar, regardless of the surgical approach.

CONCLUSIONS

Patients undergoing PCA have shorter hospital stay and PCA was more frequently used in older patients and posterior tumors. Whereas LCA was associated with lower incidence rate of perirenal hematoma. Further multicenter, prospective and long-term follow-up RCTs are required to verify these findings.

[Ablative therapy in kidney cancer: Oncological, functional, perioperative outcomes and cost]

INTRODUCTION

The incidence of kidney cancer has increased significantly over the past few decades presumably due to the increased use of imaging. The aim of this article is to describe contemporary outcomes of ablative therapy and to compare them to other therapeutic options in terms of oncological, functional, perioperative outcomes and cost.

MATERIAL AND METHODS

We searched MEDLINE^®, Embase^®, using (MeSH) words; from January 2005 through May 2017, and we looked for all the studies. Investigators graded the strength of evidence in terms of methodology, language and relevance.

RESULTS

Ninety-one articles were analyzed. We described the outcomes of ablative therapy in relation to the energy used and the approach, and compared these outcomes to the other therapeutic options in terms of oncological, functional and perioperative outcomes. We analyzed these studies in order to search for predictive factors influencing the results of ablative therapy. We also analyzed the economic burden of small renal tumor management.

CONCLUSION

The strength of evidence is based almost entirely on retrospective studies and is susceptible to the inherent limitations of this study design. Although, the evidence was low among studies, our revue showed that, in elderly patients treated with ablative therapy for cT1a tumors, the cancer-specific survival was comparable to partial nephrectomy with differences in overall survival that are explained by competing risks of death in the old population. Considering the functional results, the renal function preservation seems to be comparable between the 2 groups while the perioperative morbidity is higher in the partial nephrectomy group. The evidence base medicine at this time cannot support the extension of the indications of ablative therapy beyond the actual implementations.

Current Role of Active Surveillance in the Management of a Small Renal Mass

Renal cell carcinoma accounts for 3-4% of adult malignant neoplasms and over 65,000 new cases of kidney cancer were diagnosed in the USA in 2013 [1, 2]. Widespread use of abdominal imaging is leading to an increased incidence in the detection of small renal masses (SRMs) among other causes [1-4]. In light of recent literature on the role of percutaneous renal mass biopsy and retrospective data analysis, surveillance for renal masses ≤4 cm is likely to become more common especially in patients with less aggressive pathology, advanced age and multiple medical comorbidities.

Trends in the Management of Small Renal Masses: A Survey of Members of the Endourological Society

Treatment modalities for small renal masses (SRMs) include open or minimally invasive radical or partial nephrectomy, and laparoscopic or percutaneous ablations. Members of the Endourological Society were surveyed to evaluate how practitioner and clinical practice characteristics may be associated with the management of SRMs over time. The survey assessed characteristics of urologists (recency of residency and fellowship training, clinical practice type and location, and treatment modalities available) and their management of SRMs over the past year and over the course of the year 5 years prior. Of the 1495 surveys e-mailed, there were 129 respondents (8.6%). Comparing the past year to 5 years prior, there was increasing utilization of robotic partial nephrectomy (p < 0.001) and robotic radial nephrectomy (p = 0.031). In contrast, there was decreasing utilization of open partial nephrectomy (p < 0.001), open radical nephrectomy (p = 0.039), laparoscopic partial nephrectomy (p = 0.002), and laparoscopic radical nephrectomy (p = 0.041). Employment of laparoscopic ablation decreased (p = 0.001), but that of percutaneous ablation did not change significantly. For masses treated with image-guided therapy, there was increasing utilization of microwave ablation (p = 0.008) and decreasing usage of radiofrequency ablation (p = 0.002). Future studies should focus on the most effective treatment modalities based on provider, patient, and tumor characteristics.

Salvage Surgery After Renal Mass Ablation

Thermal ablative techniques represent treatment options for patients with small renal masses who are not candidates for surgery. The oncologic efficacy of ablation has not been compared in a randomized fashion with nephron-sparing surgery, and the urologist must be knowledgeable regarding the workup and treatment of patients with suspected residual or recurrent tumor following these therapies. Surveillance of patients with tumor recurrence after ablation may be indicated in select circumstances. When patients are deemed appropriate for salvage therapy, most undergo a repeat course of the same ablative modality. Salvage surgery is possible but often complicated by the prior ablative techniques.

Ablative Therapy for Small Renal Masses

The management of small renal masses has become an important public health topic. The increased use of cross-sectional imaging and ultrasound has led to a downward stage migration for the detection of small renal masses. Cancer-specific survival, however, has not reflected this trend accordingly. Although partial nephrectomy has been the mainstay of treatment of small renal masses less than 4 cm, there is growing interest in ablative therapies, such as cryoablation and radiofrequency ablation, due to decreased morbidity. Oncologic outcomes are limited by methodology and length of follow-up, but short-term recurrence rates are low.

Percutaneous image-guided cryoablation: current applications and results in the oncologic field

Percutaneous imaging-guided cryoablation (PICA) is a recently developed technique, which applies extreme hypothermia to destroy tumours under close imaging surveillance. It is minimally invasive, safe, repeatable, and does not interrupt or compromise other oncologic therapies. It presents several advantages over more established heat-based thermal ablation techniques (e.g. radiofrequency ablation; RFA) including intrinsic analgesic properties, superior monitoring capability on multi-modal imaging, ability to treat larger tumours, and preservation of tissue collagenous architecture. There has been a recent large increase in reports evaluating the utility of PICA in a wide range of patients and tumours, but systematic analysis of the literature is challenging due to the rapid pace of change and predominance of extensively heterogeneous level III studies. The precise onco-therapeutic role of PICA has not been established. This narrative review outlines the available evidence for PICA in a range of tumours. Current indications include curative therapy of small T1a renal tumours; curative/palliative therapy of small primary/secondary lung tumours where RFA is unsuitable; palliation of painful bone metastases; and urologic treatment of organ-confined prostate cancer. There is growing evidence to support its use for small hepatic tumours, and encouraging results have been obtained for breast tumours, extra-abdominal desmoid tumours, and management of higher-stage tumours and oligometastatic disease. However, the overall evidence base is weak, effectively restricting PICA to cases where standard therapy and RFA are unsuitable. As the technique and evidence continue to mature, the benefits of this emerging technique will hopefully become more widely available to cancer patients in the future.

Oncological outcomes and complication rates after laparoscopic-assisted cryoablation: a European Registry for Renal Cryoablation (EuRECA) multi-institutional study

OBJECTIVE

To assess complication rates and intermediate oncological outcomes of laparoscopic-assisted cryoablation (LCA) in patients with small renal masses (SRMs).

PATIENTS AND METHODS

A retrospective review of 808 patients treated with LCA for T1a SRMs from 2005 to 2015 at eight European institutions. Complications were analysed according to the Clavien-Dindo classification. Kaplan-Meier analyses were used to estimate 5- and 10-year disease-free survival (DFS) and overall survival (OS).

RESULTS

The median [interquartile (IQR)] age was 67 (58-74) years. The median (IQR) tumour size was 25 (19-30) mm. The transperitoneal approach was used in 77.7% of the patients. The median postoperative hospital stay was 2 days. In all, 514 patients with a biopsy-confirmed renal cell carcinoma (RCC) were available for survival analyses. The median (IQR) follow-up for the RCC-cohort was 36 (14-56) months. A total of 32 patients (6.2%) were diagnosed with treatment failure. The 5-/10-year DFS was 90.4%/80.0% and 5-/10-year OS was 83.2%/64.4%, respectively. A total of 134 postoperative complications (16.6%) were reported, with severe complications (grade ≥III) in 26 patients (3.2%). An American Society of Anesthesiologists score of 3 was associated with an increased risk of overall complications (odds ratio 2.85, 95% confidence interval 1.32-6.20; P = 0.005).

CONCLUSIONS

This large series of LCA demonstrates satisfactory long-term oncological outcomes for SRMs. However, although LCA is considered a minimally invasive procedure, risk of complications should be considered when counselling patients.

Contemporary Status of Percutaneous Ablation for the Small Renal Mass

Renal cell carcinoma is the tenth most common malignancy in the USA, with upwards of 61,000 new cases and resulting in more than 14,000 deaths annually. Although partial nephrectomy remains the standard treatment, image-guided nephron-sparing ablative techniques including cryoablation, radiofrequency ablation, and microwave ablation have emerged as treatment options in certain patient populations. Ablative therapies have high technical successes, low tumor recurrence rates, and preserve renal parenchymal volume. The purpose of this article is to provide an update on ablation therapies for small renal masses.

Computed Tomography Perfusion, Magnetic Resonance Imaging, and Histopathological Findings After Laparoscopic Renal Cryoablation: An In Vivo Pig Model

The present study investigates how computed tomography perfusion scans and magnetic resonance imaging correlates with the histopathological alterations in renal tissue after cryoablation. A total of 15 pigs were subjected to laparoscopic-assisted cryoablation on both kidneys. After intervention, each animal was randomized to a postoperative follow-up period of 1, 2, or 4 weeks, after which computed tomography perfusion and magnetic resonance imaging scans were performed. Immediately after imaging, open bilateral nephrectomy was performed allowing for histopathological examination of the cryolesions. On computed tomography perfusion and magnetic resonance imaging examinations, rim enhancement was observed in the transition zone of the cryolesion 1week after laparoscopic-assisted cryoablation. This rim enhancement was found to subside after 2 and 4 weeks of follow-up, which was consistent with the microscopic examinations revealing of fibrotic scar tissue formation in the peripheral zone of the cryolesion. On T2 magnetic resonance imaging sequences, a thin hypointense rim surrounded the cryolesion, separating it from the adjacent renal parenchyma. Microscopic examinations revealed hemorrhage and later hemosiderin located in the peripheral zone. No nodular or diffuse contrast enhancement was found in the central zone of the cryolesions at any follow-up stage on neither computed tomography perfusion nor magnetic resonance imaging. On microscopic examinations, the central zone was found to consist of coagulative necrosis 1 week after laparoscopic-assisted cryoablation, which was partially replaced by fibrotic scar tissue 4 weeks following laparoscopic-assisted cryoablation. Both computed tomography perfusion and magnetic resonance imaging found the renal collecting system to be involved at all 3 stages of follow-up, but on microscopic examination, the urothelium was found to be intact in all cases. In conclusion, cryoablation effectively destroyed renal parenchyma, leaving the urothelium intact. Both computed tomography perfusion and magnetic resonance imaging reflect the microscopic findings but with some differences, especially regarding the peripheral zone. Magnetic resonance imaging seems an attractive modality for early postoperative follow-up.

Percutaneous image-guided cryoablation of small renal masses

Renal cell carcinoma is a common malignancy with increasing incidence due to the incidental detection of non-symptomatic small renal masses on imaging. Management of these small tumors has evolved toward minimally invasive nephron-sparing techniques which include partial nephrectomy and image-guided ablation. Cryoablation and radiofrequency ablation are the most utilized ablation modalities with the former more suited for larger and central renal masses due to intra-procedural visualization of the ablation zone and reduced pelvicalyceal injury. In this article, we review the epidemiology and natural history of renal cell carcinoma, the role of biopsy, and the management options available-surgery, image-guided ablation, and active surveillance-with a focus on cryoablation. The clinical outcomes of the longer term maturing cryoablation data are discussed with reference to partial nephrectomy and radiofrequency ablation. Image-guided ablation has often been the management choice in patients deemed unfit for surgery; however, growing evidence from published series demonstrates image-guided ablation as a sound alternative treatment with equivalent oncological outcomes and minimal patient impact.

Current Status of Focal Cryoablation for Small Renal Masses

Focal cryoablation is an established minimally invasive technique for the treatment of small renal masses. Because of the lack of robust evidence, it is indicated in selected patients who have relative contraindications to extirpative approaches. With appropriate selection of patients, cryoablation is safe and effective. Main advantages are low risk for complication, minimal invasiveness, and good functional outcomes; oncological outcomes require further studies. The role of the percutaneous approach has been expanding because of its ability to reduce pain and hospitalization, the possibility of performing the procedure under sedation, and the fact that it is potentially more cost effective.

Kidney cancer focal cryoablation trend: does location or approach matter?

PURPOSE

We evaluated the current indications and surgical and survival outcomes for cryoablation (CA) using either a percutaneous (PCA) or a laparoscopic approach (LCA). We also investigated the ability of the PADUA score to predict the risk of complications and local recurrence.

METHODS

A retrospective analysis was performed at two European tertiary referral centers. Parameters analyzed included size, location, approach, operative time, hospital stay, complications, and functional and oncologic outcomes. Univariate and multivariate analyses were performed. An ROC analysis was conducted to evaluate the accuracy of the PADUA score.

RESULTS

Eighty patients were included. Mean tumor size was 2.6 cm. PCA was more often performed in posterior (95 vs. 60 %), inferior (72 vs. 32 %), and lateral (87 vs. 55 %) tumors. The global complication rate was 8.75 %, although proximity to the renal sinus resulted in a higher rate (30 vs. 4 %). Mean follow-up was 34 and 23 months for LCA and PCA, respectively. The 5-year recurrence-free survival was 76 and 90 % for LCA and PCA, respectively. Multivariate analysis showed that tumor involvement of the collecting system was predictive of recurrence. Under ROC analysis, PADUA score was a mild predictor for complications (AUC = 0.601) and a good predictor for recurrence (AUC = 0.723); PADUA ≥8 was identified as a cutoff for patients to a higher risk of recurrence.

CONCLUSIONS

The percutaneous approach is confirmed to be the preferred CA technique for posterior and lateral tumors. CA in deeper renal lesions and tumors with PADUA score ≥8 might entail a higher risk of recurrence, and closer follow-up should be considered in these patients.

Comparison of Postoperative Complications and Mortality Between Laparoscopic and Percutaneous Local Tumor Ablation for T1a Renal Cell Carcinoma: A Population-based Study

OBJECTIVE

To evaluate potential differences in local tumor ablation (LTA) perioperative outcomes between the percutaneous LTA (pLTA) and the laparoscopic LTA (lapLTA) approaches.

METHODS

Using the Surveillance, Epidemiology, and End Results-Medicare, we identified all patients diagnosed with T1a renal cell carcinoma (RCC) who underwent either pLTA or lapLTA between 2000 and 2009. Overall complications at 30 days and mortality at 90 days were examined for both groups. A multivariable logistic regression model was fitted to evaluate the effect of the approach on perioperative complications. A second model was fitted to test for associations between patient or tumor characteristics and type of LTA approach.

RESULTS

Overall, 516 patients diagnosed with T1a RCC were identified. Of those, 289 (56%) were treated with pLTA and 227 (44%) were treated with lapLTA. LapLTA-treated patients were younger (median 76 vs 78, P < .001) and healthier (median Charlson comorbidity index 2.1 vs 2.7, P = .03) than their counterpart. After pLTA and lapLTA, overall complication rates were 21% and 25%, respectively (P = .3). Similarly, 90-day mortality rates did not differ between the two groups (P = 1). After adjusting for patient and tumor characteristics, LTA approach was not associated with perioperative complications (odds ratio: 1.38, P = .1). However, older and sicker patients were less likely to be treated with lapLTA (both ≤ 0.04).

CONCLUSION

No differences in 30-day overall complications or 90-day mortality rates were detected between lapLTA and pLTA for T1a RCC. pLTA was more frequently used in older and sicker individuals. Further prospective studies comparing both procedures should be undertaken.