Cryoablation Of Small Renal Masses Research Articles

Percutaneous Microwave Ablation versus Cryoablation for Small Renal Masses (≤4 cm): 12-Year Experience at a Single Center

PurposeTo determine whether microwave ablation (MWA) has equivalent outcomes to those of cryoablation (CA) in terms of technical success, adverse events, local tumor recurrence, and survival in adult patients with solid enhancing renal masses ≤4 cm. Materials and MethodsA retrospective review was performed of 279 small renal masses (≤4 cm) in 257 patients (median age, 71 years; range, 40–92 years) treated with either CA (n = 191) or MWA (n = 88) between January 2008 and December 2020 at a single high-volume institution. Evaluations of adverse events, treatment effectiveness, and therapeutic outcomes were conducted for both MWA and CA. Disease-free, metastatic-free, and cancer-specific survival rates were tabulated. The estimated glomerular filtration rate was employed to examine treatment-related alterations in renal function. ResultsNo difference in patient age (P = .99) or sex (P = .06) was observed between the MWA and CA groups. Cryoablated lesions were larger (P < .01) and of greater complexity (P = .03). The technical success rate for MWA was 100%, whereas 1 of 191 cryoablated lesions required retreatment for residual tumor. There was no impact on renal function after CA (P = .76) or MWA (P = .49). Secondary analysis using propensity score matching demonstrated no significant differences in local recurrence rates (P = .39), adverse event rates (P = .20), cancer-free survival (P = .76), or overall survival (P = .19) when comparing matched cohorts of patients who underwent MWA and CA. ConclusionsHigh technical success and local disease control were achieved for both MWA and CA. Cancer-specific survival was equivalent. Higher adverse event rates after CA may reflect the tendency to treat larger, more complex lesions with CA.

Cryoablation of small renal masses in patients with solitary kidneys: worth crossing the road for?

Cryoablation of small renal masses in patients with solitary kidneys: worth crossing the road for?

Outcomes of cryoablation for small renal masses: a single-institution study

Background: The current study reports the clinical outcomes of the efficacy of computerized tomography (CT) guided cryoablation (CA) in the treatment of patients with small renal masses.Methods: This retrospective single institution study analyses the clinical outcomes of 36 renal tumours that were managed with cryoablation. Patient age, sex, tumour size, complications and recurrences were recorded. These patients were followed up at 3,6- and 12-months interval, they underwent biopsy and abdominal contrast enhanced ultrasound (CEUS) depending upon indications.Results: 36 patients (63.9% male, 19.4% female) each with a single small renal mass had CA with a follow-up at 3, 6 and 12 months. The mean tumour size was 606.9±31.8 mm2. Eleven complications occurred in 36 patients, for an overall complication rate of 30.6%. One (2.7%) patient had enhancement at the surgical bed on initial imaging and were considered incomplete ablations. None of the patients showed signs of distant metastases at the 3, 6 and 12-month follow-ups.Conclusions: Cryoablation of renal masses results in acceptable oncologic efficacy with an acceptable number of complications. Therefore, it remains a viable treatment for renal masses.

P105 - 3D virtual models for planning percutaneous Cryoablation of small renal masses

P105 - 3D virtual models for planning percutaneous Cryoablation of small renal masses

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.

V6 - Cryoablation of small renal masses – preliminary first year experience

V6 - Cryoablation of small renal masses – preliminary first year experience

UP08 - Cryoablation for small renal masses: 15 years of experience at a tertiary referral center

UP08 - Cryoablation for small renal masses: 15 years of experience at a tertiary referral center

MP42-08 THE CHANGING TRENDS OF IMAGE GUIDED BIOPSY OF SMALL RENAL MASSES BEFORE INTERVENTION- AN ANALYSIS OF EUROPEAN MULTINATIONAL PROSPECTIVE EuRECA REGISTRY

You have accessJournal of UrologyKidney Cancer: Localized: Surgical Therapy III (MP42)1 Sep 2021MP42-08 THE CHANGING TRENDS OF IMAGE GUIDED BIOPSY OF SMALL RENAL MASSES BEFORE INTERVENTION- AN ANALYSIS OF EUROPEAN MULTINATIONAL PROSPECTIVE EuRECA REGISTRY Vinson Wai-Shun Chan, Francis Keeley, Brunolf Lagerveld, Tommy Nielsen, Patricia Zondervan, Giovanni Lughezzani, and Tze Min Wah Vinson Wai-Shun ChanVinson Wai-Shun Chan More articles by this author , Francis KeeleyFrancis Keeley More articles by this author , Brunolf LagerveldBrunolf Lagerveld More articles by this author , Tommy NielsenTommy Nielsen More articles by this author , Patricia ZondervanPatricia Zondervan More articles by this author , Giovanni LughezzaniGiovanni Lughezzani More articles by this author , and Tze Min WahTze Min Wah More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002063.08AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Performing image-guided biopsy of incidental small renal masses (SRMs) pre-treatment to minimise overtreatment of benign renal masses is advocated. This study aims to assess the trends and potential factors influencing the decision to perform image-guided biopsy before cryoablation treatment. METHODS: From December 2014 to October 2020, patients with T1N0M0 SRMs undergoing percutaneous cryoablation from 14 European institutions within the European Registry For Renal Cryoablation (EuRECA) were included for the retrospective analysis. The trends of performing image-guided biopsy as a separate session before cryoablation of SRMs were analysed over time, and the potential factors influencing the decision to perform image-guided biopsy before treatment were analysed using multivariate logistic regression model. RESULTS: 1,050 patients were evaluated. The use of pre-cryoablation biopsy has significantly increased from 39% (67/171) in 2015 to 72% (88/122) in 2019 (p <0.001; figure 1). Rates of undiagnosed histology and benign histology is significantly higher in patients undergoing biopsy at the time of treatment (16% [50/313] vs 0.16% [1/636], p <0.001; Figure 2). For every 4.5 patients receiving pre-cryoablation biopsy, one less patient receives cryoablation treatment for a non-malignant renal tumor. Aged 70-79 (OR 0.53, 95% CI 0.29-0.96), 80-89 (OR 0.47, 95% CI 0.24-0.92), obesity (OR 0.73, 95% CI 0.55-0.98) and having a solitary kidney (OR 0.40, 95% CI 0.27-0.61) are three patients’ factors associated with less likelihood of pre-cryoablation biopsy (p <0.05). R.E.N.A.L. nephrometry score of 10+ (OR 1.86, 95% CI 1.11-3.10) and a Charlson Comorbidity Index >1 (OR 2.11, 95% CI 1.54-2.88) are factors associated with higher likelihood to have received a pre-cryoablation biopsy (p <0.05). CONCLUSIONS: Pre-cryoablation biopsy should be advocated as it is more likely to lead to confirmatory histological diagnosis than biopsy at the time of cryoablation, thus reducing overtreatment of non-malignant SRMs. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e774-e774 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Vinson Wai-Shun Chan More articles by this author Francis Keeley More articles by this author Brunolf Lagerveld More articles by this author Tommy Nielsen More articles by this author Patricia Zondervan More articles by this author Giovanni Lughezzani More articles by this author Tze Min Wah More articles by this author Expand All Advertisement Loading ...

Percutaneous Renal Cryoablation for Small Renal Masses: The Price is Right.

Percutaneous Renal Cryoablation for Small Renal Masses: The Price is Right.

Oncological outcomes of active surveillance and percutaneous cryoablation of small renal masses are similar at intermediate term follow-up.

Active surveillance (AS) and minimally invasive ablative therapies such as percutaneous cryoablation (PCA) are emerging as alternative treatment modalities in the management of small renal masses (SRMs). Fifty-nine patients underwent PCA since 2011 and 75 underwent AS since 2010 at two different institutions. Only patients with follow-up ≥6 months were included. All patients were followed with a standardized protocol. Treatment failure was defined by dimensional progression for AS and renal recurrence for PCA, in addition to stage and/or metastatic progression for both groups. Treatment failure was observed in 14 cases (18.7%) during AS (mainly due to dimensional progression) and 12 patients (16%) underwent delayed intervention with a mean follow-up of 36.83 months. Seven patients (11.9%) in the PCA group experienced treatment failure with a mean follow-up of 33.39 months and three of them underwent re-ablation successfully. Cancer-specific-survival at 2 and 5 years was 100% and 95,8% in AS-group vs. 98.2% and 98.2% in PCA-group (P=0.831). One patient in both groups died from metastatic disease. Overall-survival at 2 and 5 years was 91.7% and 82.4% in the AS group vs. 96.5% and 96.5% in the PCA group (P=0.113). Failure-free survival at 2 and 5 years was 90.9% and 70.1% in the AS group vs. 93.1% and 70.9% in the PCA group (P=0.645). AS and PCA provide similar survival outcomes and are safe and valid treatment options for elderly and comorbid patients with SRMs.

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

ABSTRACT 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.

Mini invasive approaches in the treatment of small renal masses: TC-guided renal cryoablation in elderly

Today, the goal of surgery is to achieve oncological efficacy with the lowest complication rate. Computed Tomography (CT)-guided cryoablation is proposed as a safe and effective technique. We report, our series of small renal masses treated with cryoablation in elderly (> 70 years). From May 2014 to April 2019, 32 patients with median (IQR) age of 75.5 years (range 71-80) with small renal masses (< T1a) diagnosis, clinical anesthesia contraindications to nephron-sparing surgery or patient's will previous informed consent have been selected at our Urology Department. All patients underwent CT-guided cryoablation, preceded by needle biopsy. The cryoablation consisted in a procedure with an argon/helium gas-based system under local anesthesia. The follow-up included CT abdomen at 3, 6 and 12 months. The definition of incomplete treatment was the persistence of the lesion contrast enhancement (CE) at the end of the scan; the definition of relapse was the appearance of the CE to the 6-month control CT. The median follow-up was 30 months (IQR 1-59). The median size of the tumor was 3.85 cm (IQR 1.6-4.5). All patients underwent lesion biopsy resulting in diagnosis of Renal Cell Carcinoma (RCC) in 29 patients (90.7%) and oncocytoma in 3 patients (9.3%). A median of 2 cryoprobes (IQR 1- 3) was used and 2/3 cycles of freeze-thaw of the duration of 10 minutes or 5 minutes were performed. Complications were: 3 asymptomatic transitional perirenal effusion, 2 lumbar pain well-controlled by analgesic drug. Hospital stay was 2 days (range 1-3). No case showed incomplete treatment and local relapse or metastates at the CT abdomen-pelvis with contrast medium at 12 months. This study shows the efficacy and safety of percutaneous cryoablation of small renal masses in elderly population. The procedure is easy to perform, with low complication rates and well tolerated by the elderly patients.

599 - 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 cT...

Renal Function Loss After Cryoablation of Small Renal Masses in Solitary Kidneys: European Registry for Renal Cryoablation Multi-Institutional Study.

Objectives: To estimate and quantify the loss of kidney function in solitary kidneys with small renal masses (SRMs) after laparoscopy-assisted renal cryoablation (LARC), from the European Registry for Renal Cryoablation (EuRECA) database. Patients and Methods: Of the 808 patients from eight European centers in the database, 102 patients had SRMs in solitary kidneys. Patient demographics, body mass index (BMI), American Society of Anesthesiologists (ASA) grade, Charlson comorbidity index, and tumor characteristics including nephrometry (PADUA) score where available were collected. Renal function data in the form of estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD) stratification both preoperatively and at 3 months postoperatively were collected. Results: The median (interquartile range [IQR]) age was 67 (59-81) years, the median (IQR) BMI was 26 (23.9-28.9) kg/m2, and the median (IQR) ASA score was 2 (2-3). The median Charlson score was 4 (range: 0-10). The median (IQR) tumor size in cross-sectional imaging was 26 (19-38) mm. The follow-up data were available for 72 patients with a median follow-up for this group of 38 (range: 10-132) months. The mean preoperative eGFR was 55.0 mL/minute/1.73 m2 (standard deviation [SD] = 18.1), and the mean postoperative eGFR was 51.8 mL/minute/1.73 m2 (SD = 18.8). The change was -3.1 mL/minute/1.73 m2 (95% confidence interval -5.2 to -1.0) units, which was statistically significant (p = 0.004). The change in the CKD stages comparing before and after LARC was not significant (paired two-tailed t-test, p = 0.06). Critically, the decrease in the eGFR did not translate to any significant adverse outcome and zero patients required dialysis. Conclusion: To the best of our knowledge, this is the largest study of renal function after LARC in SRMs in solitary kidneys. Cryotherapy in this imperative situation is safe, carries clinically insignificant reduction in renal function, therefore providing an option to minimize the risk of developing renal failure necessitating dialysis.

04:03 PM Abstract No. 90 Clinical outcomes of percutaneous cryoablation for small renal masses: a 10-year experience

Percutaneous cryoablation is safe and effective for the treatment of renal tumors, but studies examining long-term clinical outcomes are limited. The purpose of this study was to evaluate the effectiveness and adverse outcomes in a large cohort of patients undergoing percutaneous cryoablation for solid renal masses. This retrospective analysis included all 298 percutaneous cryoablation procedures (306 masses in 278 patients) performed between July 2007 and July 2018 at a single institution. The mean age in the cohort was 66.1 years (range, 30 – 93; 65.8% male). 244 masses were biopsy-proven renal cell carcinoma (RCC). Cross-sectional imaging analysis of recurrence rates, tumor staging, and long-term efficacy included only ablations for RCC. All patients were included in the analysis of procedure-related complications, including those for whom biopsy was not performed (n=8) and those with benign (n=15) or non-diagnostic (n=39) pathology. Complications were categorized according to the SIR Adverse Event Classification. The mean maximal tumor diameter was 2.3 cm (range, 0.7 - 6.6 cm). The average length of stay after cryoablation was 1.2 days (range, 1 - 8 days). Major complications occurred in 3.0% of procedures (n=9), with none resulting in death or permanent disability. There was no significant difference in pre-procedural estimated glomerular filtration rate (eGFR) and the eGFR at first follow-up (p=0.98). Among RCC patients with follow-up imaging available (n=219), the mean imaging follow-up period was 25.2 months (range, 1 – 100 months). Complete response on initial follow-up imaging was achieved in 96.3% (211 of 219) after a single session and 99.1% (217 of 219) after two sessions. Of the RCC patients achieving complete response, local recurrence during the follow-up period was seen in 2.3% (5 of 217). New metastatic disease developed in 2.7% (6 of 219) of RCC patients during follow-up. Percutaneous cryoablation is a safe and effective alternative to partial nephrectomy in the treatment of small renal masses.

P239 - Active surveillance and percutaneous cryoablation of small renal masses: Comparison of mid-term oncological outcomes

P239 - Active surveillance and percutaneous cryoablation of small renal masses: Comparison of mid-term oncological outcomes

PD51-12 COMPARISON OF MID-TERM ONCOLOGICAL OUTCOMES OF ACTIVE SURVEILLANCE AND PERCUTANEOUS CRYOABLATION OF SMALL RENAL MASSES

You have accessJournal of UrologyKidney Cancer: Localized: Active Surveillance1 Apr 2018PD51-12 COMPARISON OF MID-TERM ONCOLOGICAL OUTCOMES OF ACTIVE SURVEILLANCE AND PERCUTANEOUS CRYOABLATION OF SMALL RENAL MASSES Paolo Umari, Michele Rizzo, Michele Billia, Nicola Pavan, Gaetano Chiapparrone, Giovanni Liguori, Fulvio Stacul, Monica Zacchero, Paolo De Angelis, Alessandro Volpe, and Carlo Trombetta Paolo UmariPaolo Umari More articles by this author , Michele RizzoMichele Rizzo More articles by this author , Michele BilliaMichele Billia More articles by this author , Nicola PavanNicola Pavan More articles by this author , Gaetano ChiapparroneGaetano Chiapparrone More articles by this author , Giovanni LiguoriGiovanni Liguori More articles by this author , Fulvio StaculFulvio Stacul More articles by this author , Monica ZaccheroMonica Zacchero More articles by this author , Paolo De AngelisPaolo De Angelis More articles by this author , Alessandro VolpeAlessandro Volpe More articles by this author , and Carlo TrombettaCarlo Trombetta More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.2352AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Partial nephrectomy (PN) is considered the standard approach for small renal masses (SRMs). Active surveillance (AS) and ablative therapies represent emerging strategies for older and comorbid patients due to the indolent behaviour of most SRMs and to the high competing risk mortality. Aim of this study was to compare the mid-term oncological outcomes of AS and percutaneous cryoablation (PCA) of small renal masses (SRMs). METHODS Data regarding PCA and AS in patients with a single T1a renal tumors were collected prospectively at two large academic centers. 60 patients underwent PCA and 77 were enrolled in a AS protocol. The minimum follow-up period was 6 months. The most frequent indications for AS were severe comorbidities (48,1%), <15 mm renal masses (23,4%) and advanced age (15,6%). All patients in AS were followed with a standardized protocol including serial imaging (US, CT or MRI) every 6 months during the first 3 years and yearly thereafter. Tumor progression was defined as the reach of a 4 cm threshold in maximum diameter or a tumor volume doubling time <12 months. All PCA procedures were performed with a percutaneous approach. A double freeze-thaw cycle was performed using a mean of 2 sealed argon 17G cryoprobes per patient. Tumor progression after PCA was defined as a new nodular enhancement in the ablation zone or the enlargement of the ablated tumor 3 months after the treatment. RESULTS 14 masses showed dimensional progression during AS and 9 were surgically removed after a median follow-up of 30 months. 3 patients in the PCA group experienced progression and underwent a repeat ablation with a median follow-up of 24 months. Progression free survival (PFS) at 2 years was 94,8% and 95,0% for AS and PCA group, respectively. None of the patients progressed to metastatic disease. Overall survival at 2 years was 93,5% and 95,0% in the AS and PCA group, respectively. In the PCA group the complication rate was 5% (Clavien grade 1-2). CONCLUSIONS There are no good quality studies comparing the oncological outcomes of AS and PCA. Comparing AS to an active treatment is not an easy task due to the different definitions of the oncological endpoints such as PFS. With these limitations this study shows that both AS and PCA represent viable and safe treatment options for elderly and comorbid patients with SRMs. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e980 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Paolo Umari More articles by this author Michele Rizzo More articles by this author Michele Billia More articles by this author Nicola Pavan More articles by this author Gaetano Chiapparrone More articles by this author Giovanni Liguori More articles by this author Fulvio Stacul More articles by this author Monica Zacchero More articles by this author Paolo De Angelis More articles by this author Alessandro Volpe More articles by this author Carlo Trombetta More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

655 - Comparison of mid-term oncological outcomes of active surveillance and percutaneous cryoablation of small renal masses

655 - Comparison of mid-term oncological outcomes of active surveillance and percutaneous cryoablation of small renal masses

Safety and Efficacy of Cryoablation of Renal Tumors in a High-Risk Patient Population at a Community Hospital

Purpose: The purpose of the study was to evaluate the safety and efficacy of percutaneous cryoablation for the treatment of renal masses in a high surgical risk population stratified by Charlson Comorbidity Index treated at a community hospital and to determine parameters associated with higher complication rates. Materials and Methods: A retrospective chart review of patients with renal masses treated with image-guided percutaneous cryoablation between 2007 and 2013 was performed. Results: A total of 121 tumors were ablated in 105 patients. The mean patient age was 70 years old. Comorbidities included morbid obesity, hypertension, diabetes mellitus, coronary artery disease, pulmonary disease, cigarette use, and renal insufficiency. Mean tumor size treated was 3.15 cm in largest diameter, ranging from 1.4 to 6.5 cm. Complications were observed in 16 cases. The most common complication was perinephric and/or pararenal hemorrhage. Procedures with &gt;3.5 probes, hemoglobin &gt;12.5 g/dl, tumor size &gt;3.55 cm, and age &gt;75 years were all associated with greater likelihood of complications. Conclusions: Our experience with percutaneous cryoablation of small renal masses offers similar results in efficacy to published data in patients with significant comorbidities. In addition, the results of our study show that percutaneous cryoablation is relatively safe in patients with renal cancer who are poor surgical candidates but warrants special consideration. Parameters associated with higher rates of complications have been established, which may be used by physicians as a guide.

Percutaneous MR Imaging–Guided Cryoablation of Small Renal Masses in a 3-T Closed-Bore MR Imaging Environment: Initial Experience

PurposeTo assess the feasibility of percutaneous magnetic resonance (MR) imaging–guided cryoablation of small renal masses (SRMs) in a 3-T environment and to evaluate intraprocedural imaging, procedural safety, and initial outcomes. Materials and MethodsThe analysis included 9 patients (4 men; median age, 72 y; range, 70-82 y) with 9 SRMs (diameter, 12–30 mm). Lesions underwent biopsy, and cryoneedles were inserted under ultrasound guidance. Verification of needle positions and ice-ball monitoring were performed by T1-weighted volumetric interpolated breath-hold examination and T2-weighted half-Fourier acquired single-shot turbo spin-echo sequences. On image analysis, needle positioning was considered appropriate if the target lesion border was visible, the needle tip was inside the target lesion, and the ice ball was expected to cover the target lesion with a 5-mm margin. If these criteria could not be assessed, imaging was considered inadequate. Technical success was defined as tumor coverage with a 5-mm margin and no residual disease on 1-mo follow-up MR imaging. ResultsMedian total procedure time was 170 min (range, 135–193 min). Intraoperative imaging allowed adequate needle visualization in 67% of acquired scans (4 of 7 T1-weighted and 6 of 8 T2-weighted). Appropriate positioning of two or three needles used for each procedure was confirmed in all cases on T1- or T2-weighted imaging. Ice-ball formation was adequately visualized in all patients. Technical success rate was 100%. No local recurrences were detected on follow-up imaging at a median of 12 mo (range, 3–22 mo). ConclusionsPercutaneous MR-guided cryoablation of SRMs in a 3-T MR imaging environment is safe and feasible, showing adequate intraoperative imaging capabilities with promising short-term clinical outcomes.