A phase I oncolytic virus trial with vesicular stomatitis virus expressing human interferon beta and tyrosinase related protein 1 administered intratumorally and intravenously in uveal melanoma: safety, efficacy, and T cell responses.

Introduction: Metastatic uveal melanoma (MUM) has a poor prognosis and treatment options are limited. These patients do not typically experience durable responses to immune checkpoint inhibitors (ICIs). Oncolytic viruses (OV) represent a novel approach to immunotherapy for patients with MUM. Methods: We developed an OV with a Vesicular Stomatitis Virus (VSV) vector modified to express interferon-beta (IFN-ß) and Tyrosinase Related Protein 1 (TYRP1) (VSV-IFNß-TYRP1), and conducted a Phase 1 clinical trial with a 3 + 3 design in patients with MUM. VSV-IFNß-TYRP1 was injected into a liver metastasis, then administered on the same day as a single intravenous (IV) infusion. The primary objective was safety. Efficacy was a secondary objective. Results: 12 patients with previously treated MUM were enrolled. Median follow up was 19.1 months. 4 dose levels (DLs) were evaluated. One patient at DL4 experienced dose limiting toxicities (DLTs), including decreased platelet count (grade 3), increased aspartate aminotransferase (AST), and cytokine release syndrome (CRS). 4 patients had stable disease (SD) and 8 patients had progressive disease (PD). Interferon gamma (IFNγ) ELIspot data showed that more patients developed a T cell response to virus encoded TYRP1 at higher DLs, and a subset of patients also had a response to other melanoma antigens, including gp100, suggesting epitope spreading. 3 of the patients who responded to additional melanoma antigens were next treated with ICIs, and 2 of these patients experienced durable responses. Discussion: Our study found that VSV-IFNß -TYRP1 can be safely administered via intratumoral (IT) and IV routes in a previously treated population of patients with MUM. Although there were no clear objective radiographic responses to VSV-IFNß-TYRP1, dose-dependent immunogenicity to TYRP1 and other melanoma antigens was seen.

Safety and Efficacy of Percutaneous Image-guided Cryoablation of Completely Endophytic Renal Masses.

OBJECTIVE: To evaluate the safety, efficacy, and oncologic control of percutaneous image-guided cryoablation in the treatment of completely endophytic renal masses. Percutaneous image-guided cryoablation is a minimally invasive and effective treatment for small renal masses. Image-guided cryoablation is an attractive treatment for completely endophytic tumors given the challenge in visualization of such lesions during surgical extirpation. MATERIALS AND METHODS: A retrospective study evaluating percutaneous cryoablation of completely endophytic renal masses with normal overlying renal cortex was performed. From January 2003 to December 2015, 200 endophytic renal masses (RENAL score 3 - endophytic/exophytic) were identified from an internal renal ablation database. After imaging review, 49 tumors with completely intact overlying renal cortex in 47 patients were included in the study. Outcomes, including complications and oncologic efficacy were evaluated according to standard nomenclature. RESULTS: Patients comprised 37 men and 10 women (mean age 64.0 years) who underwent 48 cryoablation procedures to treat 49 renal masses. Mean tumor size was 2.5 ± 0.5 cm. Major complications occurred following 5 of the 48 (10%) procedures. Forty of 46 (87%) tumors with imaging follow-up were recurrence-free at a mean of 56 months. Five of six local recurrences were successfully retreated with cryoablatoin. CONCLUSION: Percutaneous thermal ablation of completely endophytic renal masses is a relatively safe procedure associated with acceptable complication and local tumor control rates. Given the complexities associated with partial nephrectomy, percutaneous cryoablation may be considered an alternative treatment for these select patients. Long-term follow-up studies are necessary to determine the durable efficacy of this treatment.

Incidence of major hemorrhage after aggressive image-guided liver mass biopsy in the era of individualized medicine.

PURPOSE: To analyze a large volume of image-guided liver mass biopsies to assess for an increased incidence of major hemorrhage after aggressive liver mass sampling, and to determine if coaxial technique reduces major hemorrhage rate. METHODS: Patients who underwent image-guided liver mass biopsy over a 15-year period (December 7, 2001-September 22, 2016) were retrospectively identified. An aggressive biopsy was defined as a biopsy event in which ≥ 4 core needle passes were performed. Association of major hemorrhage after aggressive liver mass biopsy and other potential risk factors of interest were assessed using logistic regression analysis. For the subset of aggressive biopsies, Fisher's exact test was used to compare the incidence of major hemorrhage using coaxial versus noncoaxial techniques. RESULTS: Aggressive biopsies constituted 11.6% of biopsy events (N =579/5011). The incidence of major hemorrhage with <4 passes was 0.4% (N =18/4432) and with ≥4 passes 1.2% (N =6/579). In univariable models, aggressive biopsy was significantly associated with major hemorrhage (OR 3.0, 95% CI 1.16-6.92, p =0.025). After adjusting for gender and platelet count, the association was not significant at the p =0.05 level (OR 2.58, 95% CI 0.927-6.24, p =0.067). The rate of major hemorrhage in the coaxial biopsy technique group was 1.4% (N =3/209) compared to 1.1% (N =4/370) in the noncoaxial biopsy technique group, which was not a significant difference (p =0.707). CONCLUSIONS: Although aggressive image-guided liver mass biopsies had an increased incidence of major hemorrhage, the overall risk of bleeding remained low. The benefit of such biopsies will almost certainly outweigh the risk in most patients.

Introduction of Microwave Ablation Into a Renal Ablation Practice: Valuable Lessons Learned.

OBJECTIVE: The purpose of this study was to evaluate the early outcomes of percutaneous microwave ablation (MWA) for clinical stage T1 (cT1) renal masses when performed within a high-volume ablation practice with critical emphasis on procedural safety. MATERIALS AND METHODS: A retrospective review of a percutaneous renal ablation registry identified 26 patients with a total of 27 cT1 renal masses treated with MWA between 2011 and 2017. Mean patient age was 63.8 years and 16 (61.5%) patients were male. Mean renal mass size ± SD was 2.3 ± 0.8 cm (range, 1.1-4.7 cm). The main outcome parameters investigated were technical success, local tumor progression, survival rates, and complications. Complications were categorized using the Clavien-Dindo classification system. Rates of local progression-free and cancer-specific survival (PFS and CSS, respectively) were estimated using the Kaplan-Meier method. RESULTS: Technical success was 100% on contrast-enhanced CT or MRI performed immediately after renal MWA. Twenty-four patients (92%) with 25 tumors had follow-up imaging for 3 months or longer (mean, 20.6 ± 11.6 months), with no local tumor recurrences identified. Estimated 3-year local PFS and CSS were 96% and 94%, respectively. The overall complication rate was 19.2%; two patients (7.7%) experienced minor complications (grade I or II) and three patients (11.5%) experienced major bleeding or urinary-related complications (grade III or higher), including one death. CONCLUSION: This study suggests that percutaneous MWA is a promising minimally invasive treatment option for cT1 renal masses. Nonetheless, major bleeding and urinary-related complications can occur, and further studies are needed to determine optimal patient and tumor selection for renal MWA.

Outcomes After Cryoablation Versus Partial Nephrectomy for Sporadic Renal Tumors in a Solitary Kidney: A Propensity Score Analysis.

BACKGROUND: While partial nephrectomy (PN) is considered the standard approach for a tumor in a solitary kidney, percutaneous cryoablation (PCA) is emerging as an alternative nephron-sparing option. OBJECTIVE: To compare outcomes between PCA and PN for tumors in a solitary kidney. DESIGN, SETTING, AND PARTICIPANTS: Patients who underwent PCA or PN between 2005 and 2015 for a single primary renal tumor in a solitary kidney were identified using Mayo Clinic Registries. Exclusion criteria were inherited tumor syndromes and salvage procedures. INTERVENTION: PCA and PN. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: To achieve balance in baseline characteristics, we used inverse probability of treatment weighting (IPTW) based on propensity to receive treatment. The risk of having a post-treatment complication and percent drop in estimated glomerular filtration rate (eGFR), as well as the risks of local/ipsilateral recurrence, distant metastasis, and cancer-specific mortality, were compared between groups using logistic, linear, and Fine-and-Gray competing risk regression models. RESULTS AND LIMITATIONS: The cohort included 118 patients (PCA: 54; PN: 64) with a median follow-up of 47 mo (interquartile range 18, 74). In unadjusted analyses, PCA was associated with a lower risk of complications (15% vs 31%; odds ratio [OR]=0.38; 95% confidence interval [CI] 0.15, 0.96; p=0.04). However, upon accounting for baseline differences with IPTW adjustment, there was no longer a significant difference in the risk of complications (28% vs 29%; OR=0.95; 95% CI 0.53, 1.69; p=0.9). There were no significant differences between PCA and PN in percentage drop in eGFR at discharge (mean: 11% vs 16%; ß=-5%; 95% CI -13, 3; p=0.2) or at 3 mo (12% vs 9%; ß=3%; 95% CI -3, 10; p=0.3). Likewise, no significant differences were noted in local recurrence (HR=0.87; 95% CI 0.38, 1.98; p=0.7), distant metastases (HR=0.60; 95% CI 0.30, 1.20; p=0.2), or cancer-specific mortality (HR=1.13; 95% CI 0.32, 3.98; p=0.8). Limitations include the sample size, given the relative rarity of renal masses in solitary kidneys. CONCLUSIONS: Our study found no significant difference in complications, renal function outcomes, and oncologic outcomes between PN and PCA for patients with a tumor in a solitary kidney. Validation in a larger multi-institutional analysis may be warranted. PATIENT SUMMARY: Partial nephrectomy (surgery) and percutaneous cryoablation are both options for treating a kidney tumor while preserving the normal portion of the kidney. In patients with a tumor in their only kidney, we found no difference in the risk of complications, kidney function outcomes, or cancer control outcomes between these two approaches.

Retrospective Review of Percutaneous Image-Guided Ablation of Oligometastatic Prostate Cancer: A Single-Institution Experience.

PURPOSE: To retrospectively review and report the efficacy and safety of percutaneous image-guided ablation (cryoablation or radiofrequency ablation) in the treatment of oligometastatic prostate cancer. MATERIALS AND METHODS: An institutional registry was retrospectively reviewed and revealed 16 patients with oligometastatic prostate cancer (median age, 67 y; range, 50-86 y) who underwent percutaneous image-guided ablation to treat 18 metastatic sites. A subgroup of 7 patients with 8 metastases were androgen-deprivation therapy (ADT)-naïve and underwent ablation to delay initiation of ADT. Local tumor control, progression-free survival (PFS), ADT-free survival, and procedural complications were analyzed. RESULTS: Local tumor control was achieved in 15 of 18 metastases (83%) at a median follow-up of 27 months (range, 5-56 mo). Local tumor recurrence was found in 3 of 18 metastases (17%), with a median time to local recurrence of 3.5 months (range, 3-38 mo). Estimated PFS rates at 12 and 24 months were 56% (95% confidence interval [CI], 30%-76%) and 43% (95% CI, 19%-65%), respectively. In the 7 ADT-naïve patients, local tumor control was achieved in all metastases, and the median ADT-free survival period was 29 months. There were no major procedural complications. CONCLUSIONS: In this cohort of patients with oligometastatic prostate cancer, percutaneous image-guided ablation was feasible and well tolerated and achieved acceptable local tumor control rates. Percutaneous ablation may be of particular utility in patients who wish to delay initiation of ADT.

Avoiding Complications in Bone and Soft Tissue Ablation.

As with percutaneous ablation of tumors in the liver, lungs, and kidneys, ablation of bone and non-visceral soft tissue tumors carries risk, primarily from collateral damage to vital structures in proximity to the target tumor. Certain risks are of particular interest when ablating bone and non-visceral soft tissue tumors, namely neural or skin injury, bowel injury, fracture, and gas embolism from damaged applicators. Ablation of large volume tumors also carries special risk. Many techniques may be employed by the interventional radiologist to minimize complications when treating tumors in the musculoskeletal system. These methods include those to depict, displace, or monitor critical structures. Thus, measures to provide thermoprotection may be active, such as careful ablation applicator placement and use of various displacement techniques, as well as passive, including employment of direct temperature, radiographic, or neurophysiologic monitoring techniques. Cementoplasty should be considered in certain skeletal locations at risk of fracture. Patients treated with large volume tumors should be monitored for renal dysfunction and properly hydrated. Finally, ablation applicators should be cautiously placed in the constrained environment of intact bone.

Percutaneous Cryoablation of Extraabdominal Desmoid Tumors: A 10-Year Experience.

OBJECTIVE: Extraabdominal desmoid (EAD) tumors pose a therapeutic challenge because they often recur locally and behave aggressively. Accepted management options include surgery, radiation, chemotherapy, and observation. The objective of this study was to assess the safety and efficacy of percutaneous cryoablation for the treatment of EAD tumors. MATERIALS AND METHODS: A retrospective search of our cryoablation database was performed to identify patients with EAD tumors treated with percutaneous cryoablation between June 15, 2004, and June 15, 2014. During this 10-year time period, we treated 18 patients with 26 discrete tumors during 31 treatment sessions. After cryoablation, contrast-enhanced MRI or CT was performed. Any enhancing soft tissue was considered viable EAD tumor and was measured in three planes. RESULTS: Of the 26 EAD tumors treated, follow-up imaging with IV contrast material was available for 23 tumors. The mean imaging follow-up was 16.2 ± 20.0 (SD) months. All 31 sessions were technically successful procedures. No residual viable EAD tumor was observed in nine of 23 tumors (39.1%). Some degree of volume reduction was evident in 22 of 23 tumors (95.7%). Progressive disease was observed in one of the 23 tumors (4.3%). Of the cases with residual or progressive disease, the recurrence occurred at the margin of the treated tumor in all cases. No major complications were observed, and none of the complications was more severe than Clavien-Dindo grade I. CONCLUSION: Percutaneous cryoablation is a safe, effective, and repeatable treatment for achieving local control of EAD tumors.

Incidence of bleeding complications after percutaneous core needle biopsy in hypertensive patients and comparison to normotensive patients.

PURPOSE: To retrospectively determine the rate of major bleeding complications after solid organ or lung biopsy in patients with hypertension and compare to the rates of bleeding in normotensive patients. MATERIALS AND METHODS: Following IRB approval, retrospective review of all solid organ and lung biopsies performed at our institution between June 1st, 2013 and October 31st, 2015 was performed. Hypertension was defined as a maximum observed systolic blood pressure of 160 mmHg or greater and/or diastolic blood pressure of 90 mmHg or greater at the time of the biopsy procedure. Bleeding complications were defined using the Common Terminology Criteria for Adverse Events (CTCAE, version 4.0) established by the National Cancer Institute. RESULTS: 4756 total biopsies in 3876 unique patients (median age 60, 57% male) were included. 1488 (31.3%) of these biopsies were performed in hypertensive patients. Fifteen major hemorrhages (CTCAE grade 3 or higher) occurred (0.32%). There were no deaths. There was no significant association between hypertension and major bleeding. The incidence of bleeding in hypertensive patients was 0.40% (6/1488), which was not statistically different than the incidence in normotensive patients (9/3268, 0.28%, p = 0.496). For the subgroup of native renal parenchymal biopsies, the rate of bleeding was slightly higher in hypertensive patients (3/213, 1.4% vs. 1/355, 0.28% in normotensive patients) but remained low, and the difference was not statistically significant (p = 0.188). CONCLUSION: The overall incidence of major bleeding after percutaneous biopsy is very low. Hypertension does not appear to significantly increase the risk of major bleeding complications.

Percutaneous cryoablation of stage T1b renal cell carcinoma: technique considerations, safety, and local tumor control.

PURPOSE: To describe the technical methods, safety, and local tumor control rate associated with percutaneous cryoablation of stage T1b renal cell carcinoma (RCC). MATERIALS AND METHODS: A retrospective review of a percutaneous renal ablation registry was used to identify 46 patients with a total of 46 biopsy-proven RCC lesions measuring 4.1-7.0 cm treated with cryoablation between 2003 and 2011. The main outcome parameters investigated were adjunctive maneuvers, complications, and local tumor progression, and cancer-specific survival rates. Complication rates were categorized and recorded using the Clavien-Dindo classification system. Progression-free and cancer-specific survival rates were estimated using the Kaplan-Meier method. RESULTS: The mean treated RCC size was 4.8 cm (range, 4.1-6.4 cm). Prophylactic tumor embolization was performed in 7 patients (15%), ipsilateral ureteral stents were placed in 7 patients (15%), and hydrodisplacement of bowel was performed in the treatment of 16 tumors (35%). A single technical failure (2.2%) was observed at the time of ablation. Thirty-six tumors (78%) had follow-up imaging at 3 months or later following ablation, including a single recurrence at 9 months after ablation. The mean duration of follow-up for the 35 RCC tumors that did not recur was 2.0 years (range, 0.3-6.1 y). Estimated local progression-free survival rate at 3 years was 96.4%. Of the 46 cryoablation procedures, there were 7 complications (15.2%) of grade II or worse. CONCLUSIONS: The results suggest that cryoablation represents a valid treatment alternative for select patients with clinical stage T1b RCC. Complications are frequent enough that multidisciplinary patient management should be considered.

Percutaneous Clinical T1a Renal Mass Ablation in the Octogenarian and Nonagenarian: Oncologic Outcomes and Morbidity.

PURPOSE: To evaluate outcomes of percutaneous ablation of small renal tumors in the elderly population. PATIENTS AND METHODS: Using our tumor ablation database, we searched for percutaneous ablation procedures for clinical T1a renal masses in octogenarians and nonagenarians between June 2001 and May 2012. Altogether, 105 tumors from 99 procedures among 95 patients (mean age 84.0±3.0 years, range 80-92) were identified. Oncologic outcomes and major complications were evaluated. Assessment also included patient hospital stays and renal functional outcomes. RESULTS: Technical success was achieved in 60/61 (98.4%) tumors managed with cryoablation and 43/44 (97.7%) after radiofrequency ablation (RFA). Of 87 renal tumors with at least 3 months imaging follow-up, 2 (5.4%) tumors progressed at 1.2 and 2.2 years after RFA. None recurred after cryoablation. Estimated progression-free survival rates at 1, 3, and 5 years after ablation were 99%, 97%, and 97%, respectively. Thirty-four patients died at a mean of 3.7 years after ablation (median 3.7; range 0.4-9.6). Estimated overall survival rates were 98%, 83%, and 61%, respectively. Among 33 patients with sporadic, biopsy-proven renal-cell carcinoma, estimated cancer-specific survival rates were 100%, 100%, and 86%, respectively. Five (8.6%) major complications developed after renal cryoablation with no (0%) major complication after RFA. Mean decrease in serum creatinine level within 1 week after ablation was 0.1 mg/dL. Mean hospitalization was 1.2 days. CONCLUSION: Percutaneous thermal ablation is safe and effective in the active management of clinical T1a renal masses in elderly patients. These results should help urologists appropriately assess expected outcomes when counseling octogenarian and nonagenarian patients.

Cryoablation of sternal metastases for pain palliation and local tumor control.

PURPOSE: To determine safety and effectiveness of cryoablation of sternal metastases for pain palliation and local tumor control. MATERIALS AND METHODS: A tumor ablation database was retrospectively reviewed for sternal cryoablation procedures performed between January 2005 and June 2013, which yielded 15 procedures to treat 12 sternal metastases in 12 patients (five men). Median patient age was 57 years (range, 38-80 y). Metastases arose from five primary sites (breast, lung, kidney, ampulla, and thyroid), and median tumor size was 3.8 cm (range, 2.2-7.5 cm). Seven patients (58%) underwent cryoablation for pain palliation, and five (42%) underwent cryoablation for local tumor control of oligometastatic disease. Clinical outcomes (including complications, local tumor control, and pain response) were evaluated retrospectively. RESULTS: Mean pain scores decreased from 7.0 ± 1.9 (median, 7; range, 4-10) at baseline to 1.8 ± 1.2 (median, 1.5; range, 0-4) following cryoablation (P = .00049). Two patients had durable pain palliation, and four had greater than 1 month of pain relief, with a median duration of 5.7 months (range, 1.5-14.7 mo). Two patients in whom recurrent pain developed underwent repeat cryoablation, with durable pain relief. Allowing for a single repeat treatment, local tumor control was achieved in four of five patients (80%) treated for this indication, with median follow-up of 8.4 months (range, 2.6-13.6 mo). In one patient (8%), an infectious complication developed that was successfully treated with antibiotics on an outpatient basis. CONCLUSIONS: Cryoablation is a safe and potentially effective treatment for patients with painful sternal metastases and can achieve local tumor control in select patients.

Predicting renal cryoablation complications: new risk score based on tumor size and location and patient history.

PURPOSE: To identify tumor and patient-related risk factors for major complications following renal cryoablation and to develop a model for predicting these adverse events. MATERIALS AND METHODS: Institutional review board approval and informed patient consent were obtained for this HIPAA-compliant retrospective study. All 398 renal cryoablation procedures performed from 2003 through 2011 were reviewed to identify tumor and patient-related risk factors associated with major complications (Clavien-Dindo classification, ≥ grade III). A scoring system for predicting these adverse events was then developed using risk factor weighting obtained from a multivariate logistic regression model. To internally validate this model, the scoring system was then applied to all 73 renal cryoablation procedures performed during 2012. RESULTS: Among tumor-related factors evaluated, Maximal tumor diameter (P = .0006) and Central tumor location (P = .02) were significantly associated with major complications. Among patient-related factors evaluated, prior Myocardial infarction (MI) (P = .002) and Complicated diabetes mellitus (P = .01) were significantly associated with major complications. This resulted in the (MC)2 risk scoring system, with (MC)2 risk score = 2.5 points (for tumors ≤ 2.5 cm in maximal diameter) or 0.1 points for each millimeter of maximal tumor diameter (for tumors > 2.5 cm) + 1.5 points (if central tumor location) + 2.5 points (if patient history of prior MI) + 3.0 points (if patient history of complicated diabetes). Mean (MC)2 risk score for all renal cryoablations was 4.7 (standard deviation, 1.9; range, 2.5-15.3). The observed major complication rates were 2.0% (95% confidence interval [CI]: 0.6%, 4.6%) in the low-risk group (score < 5.0), 12.8% (95% CI: 7.5%, 19.9%) in the moderate-risk group (score of 5.0-8.0), and 39.1% (95% CI: 19.7%, 61.5%) in the high-risk group (score > 8.0). Application of the (MC)2 scoring system to the validation group yielded a concordance index of 0.82 (95% CI: 0.62, 1.00). CONCLUSION: The results of this study suggest that the (MC)2 risk score is a valuable tool for predicting major complications in patients undergoing renal cryoablation. However, external validation is warranted.

Feasibility and oncologic control after percutaneous image guided ablation of metastatic renal cell carcinoma.

PURPOSE: We assessed the safety, local control and oncologic efficacy of percutaneous ablation in the treatment of metastatic renal cell carcinoma. MATERIALS AND METHODS: A retrospective review was performed of 61 patients who underwent 74 ablation procedures to treat 82 metastatic renal cell carcinoma lesions with the intent of local eradication. Technical success, local tumor control, complications and patient survival were analyzed according to standard criteria. RESULTS: Four (4.9%) technical failures were observed while 2 patients were lost to followup. Time to recurrence was assessed for the subset of 76 (93%) tumors that were followed after ablation. Six (of 76, 7.9%) tumors recurred at a mean of 1.6 years after ablation (median 1.4, range 0.6 to 2.9). Thus, known overall local tumor control was achieved in 70 of 80 (87.5%) tumors. Estimated local recurrence-free survival rates (95% CI, number still at risk) at 1, 2 and 3 years after ablation were 94% (88-100, 41), 94% (88-100, 32) and 83% (70-97, 17), respectively. Estimated overall survival rates (95% CI, number still at risk) at 1, 2 and 3 years after ablation were 87% (79-97, 42), 83% (73-94, 31) and 76% (63-90, 19), respectively. CONCLUSIONS: Image guided ablation of metastatic renal cell carcinoma is a relatively safe procedure with acceptable local control rates. Ablation may offer patients a minimally invasive option of local tumor eradication and warrants a role in the multimodal treatment approach for select patients.

ABLATE: a renal ablation planning algorithm.

OBJECTIVE: The purpose of this article is to present the ABLATE renal ablation planning algorithm (Table 1), which is based on anatomic renal tumor characteristics critical to ablation. [Table: see text]. CONCLUSION: ABLATE provides a systematic method for reviewing cross-sectional imaging of renal masses for ablation planning purposes. The goal of this system is to help proceduralists anticipate and manage potential technical challenges of renal ablations to maximize oncologic outcomes and minimize complications.

Ultrasound-guided transhepatic radiofrequency ablation of renal tumors: a safe and effective approach.

PURPOSE: This study was designed to determine the feasibility and safety of ultrasound-guided transhepatic radiofrequency ablation (RFA) of masses in the right kidney. METHODS: Between June 2001 and December 2011, 18 patients who underwent transhepatic renal RFA procedures to treat 19 tumors were retrospectively identified. Complications (Clavien-Dindo classification system) and local tumor control were evaluated for all patients. RESULTS: Median maximal diameter of the treated renal tumors was 1.9 (range 1.1-4.3) cm. No major complication developed during any of the procedures. No hepatic tumor seeding was identified during imaging follow-up. There was a single technical failure (5.3%). Median cross-sectional imaging follow-up was 28 (range 3-121) months. Primary technique failure (local recurrence) occurred in 1 of the 16 tumors with follow-up imaging (5.3%). CONCLUSIONS: Percutaneous ultrasound-guided transhepatic RFA of renal neoplasms is technically feasible, effective, and associated with a low rate of complications. The transhepatic approach may allow safe ablation of renal tumors that would otherwise be difficult to treat.

Percutaneous renal cryoablation in obese and morbidly obese patients.

OBJECTIVE: To compare percutaneous renal cryoablation complications and outcomes in obese and morbidly obese vs nonobese patients. METHODS: Three hundred eighty-nine percutaneous cryoablation procedures were performed in 367 patients for treatment of 421 renal masses at our institution between 2003 and 2012. Patients were categorized into 3 groups on the basis of body mass index (BMI): nonobese (BMI <30.0 kg/m(2)), obese (BMI 30.0-39.9 kg/m(2)), and morbidly obese (BMI ≥40.0 kg/m(2)). Each group was retrospectively analyzed for major complications (Clavien ≥grade 3) and oncologic outcomes. RESULTS: One hundred eighty-nine renal cryoablation procedures (48.6%) were performed on nonobese patients, 161 (41.4%) on obese patients, and 39 (10.0%) on morbidly obese patients. Eleven (5.8%) major complications occurred in nonobese patients, 15 (9.3%) in obese patients, and 3 (7.7%) in morbidly obese patients. As such, there was no significant difference in the rate of major complications in obese (P = .23) or morbidly obese (P = .67) compared with nonobese patients. There was 1 ablation-related death from complications of urosepsis. Thirteen local treatment failures were identified, including 5 technical failures and 8 local tumor recurrences during median imaging follow-up of 18 months (interquartile range: 8-36). Six local treatment failures (3.2%) occurred in nonobese patients, 5 (2.9%) in obese patients, and 2 (4.8%) in morbidly obese patients. Again, no significant difference was noted in local treatment failure rate between obese (P = .96) or morbidly obese (P = .57) compared with nonobese patients. CONCLUSION: Percutaneous renal cryoablation complication rates and short-term outcomes in obese and morbidly obese patients are similar to those in nonobese patients.

Neuroanatomic considerations in percutaneous tumor ablation.

Percutaneous ablation is increasingly being used as focal therapy for tumors in the chest, abdomen, and pelvis, including tumors in proximity to neural structures. To ensure that tumor ablation is performed safely, knowledge of the regional neuroanatomy is particularly important because most relevant nerves are not visualized with the conventional imaging techniques used to guide ablation procedures. Familiarity with the expected course of nerves in commonly targeted areas is helpful in preventing inadvertent nerve injury and in accurately informing the patient of potential risks. In the chest and shoulder girdle, the brachial plexus as well as the phrenic, recurrent laryngeal, intercostal-subcostal, long thoracic, dorsal scapular, and suprascapular nerves may be encountered. Vulnerable neural structures in the abdomen and pelvis arise from the lumbar and sacral plexuses and include the femoral, obturator, sciatic, and pudendal nerves. Nerve protection and monitoring techniques should be used, when appropriate, to minimize the risk of neural injury during percutaneous tumor ablation and depend on the vulnerable nerve, the location of the targeted tumor, and the ablation device used for treatment. Nerves may be protected using displacement techniques, including instillation of air or fluid, insertion and insufflation of angioplastic or endoscopic balloons, and mechanical manipulation of the ablation device. Nerves may be monitored with cross-sectional imaging evaluation of the critical nerve or ablation zone, or with functional evaluation using electromyographic equipment or focused clinical examination. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg334125141/-/DC1.

Percutaneous ablation of renal masses measuring 3.0 cm and smaller: comparative local control and complications after radiofrequency ablation and cryoablation.

OBJECTIVE: The purpose of this article is to compare the efficacy and complication rates of percutaneous radiofrequency ablation (RFA) and cryoablation in the treatment of renal masses measuring 3.0 cm and smaller. MATERIALS AND METHODS: A retrospective review was performed of 385 patients with 445 tumors measuring 3.0 cm or smaller treated with thermal ablation from 2000 through 2010. Two hundred fifty-six tumors in 222 patients were treated with RFA (mean [± SD] tumor size, 1.9 ± 0.5 cm), and 189 tumors in 163 patients were treated with cryoablation (mean tumor size, 2.3 ± 0.5 cm). Major complications and efficacy as measured by technical success and local tumor recurrence rates were recorded. RESULTS: There were five (1.1%) technical failures, including one (0.4%) among tumors treated with RFA and four (2.1%) among tumors treated with cryoablation (p = 0.17). Of the 218 tumors treated with RFA and with follow-up beyond 3 months, seven (3.2%) developed local tumor recurrence, at a mean of 2.8 years after treatment (range, 1.2-4.1 years). Of the 145 tumors treated with cryoablation and with follow-up beyond 3 months, four (2.8%) developed local tumor recurrence at a mean of 0.9 years after treatment (range, 0.3-1.6 years). For biopsy-proven renal cell carcinoma, estimated local recurrence-free survival rates at 1, 3, and 5 years after RFA were 100%, 98.1%, and 98.1%, respectively, compared with 97.3%, 90.6%, and 90.6%, respectively, after cryoablation (p = 0.09). Major complications occurred after 4.3% (10/232) of RFAs and 4.5% (8/176) of cryoablation procedures (p = 0.91). CONCLUSION: RFA and cryoablation are both effective in the treatment of renal masses measuring 3 cm or smaller. Major complications with either procedure are infrequent.

Percutaneous cryoablation of musculoskeletal oligometastatic disease for complete remission.

PURPOSE: To assess the safety and effectiveness of percutaneous cryoablation to treat limited metastases to the musculoskeletal system, with the goal of complete disease remission. MATERIALS AND METHODS: In a single-institution retrospective study of data from December 2003 to October 2011, 43 consecutive patients underwent initial cryoablation of limited (five or fewer) musculoskeletal metastases with the goal of complete disease remission (ie, no clinical or radiographic evidence of disease). Three patients were lost to follow-up. As a result, the present report describes 40 patients who underwent 40 cryoablation procedures to treat 52 tumors. RESULTS: Local control was achieved in 45 of 52 tumors (87%; 95% confidence interval [CI], 75%-93%) at a median follow-up of 21 months (range, 4-62 mo). Thirteen of 19 treated bone metastases (68%) and 32 of 33 soft-tissue metastases (97%) showed local control (P = .007). One- and 2-year overall survival rates were 91% (95% CI, 75%-97%) and 84% (95% CI, 65%-93%), respectively. Median overall survival was 47 months (95% CI, 26-62 mo). One- and 2-year disease-free survival rates were 22% (95% CI, 11%-37%) and 7% (95% CI,<1% to 26%), respectively. Median disease-free survival was 7 months (95% CI, 5-10 mo). Two of 40 procedures (5%) were associated with major complications. CONCLUSIONS: Percutaneous cryoablation is a safe and effective treatment to achieve local tumor control and short-term complete disease remission in patients with limited metastatic disease to the musculoskeletal system.