Anil N. Kurup

Usefulness of R.E.N.A.L. Nephrometry Scoring System for Predicting Outcomes and Complications of Percutaneous Ablation of 751 Renal Tumors

PURPOSE We applied the R.E.N.A.L. (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior and location relative to polar lines) nephrometry scoring system to renal tumors treated with percutaneous ablation to determine whether this score is associated with oncological outcomes and complications. MATERIALS AND METHODS A total of 751 renal tumors were treated at 679 percutaneous ablation sessions in 627 patients at our institution between 2000 and 2012. Of these renal masses 430 (57%) were treated with cryoablation and the remaining 321 were treated with radio frequency ablation. R.E.N.A.L. tumor scores were analyzed to determine the association of the score with ablation treatment outcomes and complications according to Clavien criteria. RESULTS The mean ± SD R.E.N.A.L. nephrometry score of all ablated tumors was 6.7 ± 1.9. Those treated with cryoablation had higher scores than those treated with radio frequency ablation (mean 7.2 ± 1.9 vs 6.1 ± 1.8, p <0.001). We identified a total of 28 local treatment failures (3.7%) in the 751 tumors during a mean computerized tomography/magnetic resonance imaging followup of 27.9 ± 27.8 months. There was a significant association between R.E.N.A.L. nephrometry score and local treatment failure. Mean nephrometry score was 7.6 ± 2.2 vs 6.7 ± 1.9 for tumors with vs without local treatment failure (p <0.001). Of the 679 ablation treatments 38 (5.6%) major (grade 3 or greater) patient complications occurred. There was a significant association between R.E.N.A.L. nephrometry score and major complications. Patients with vs without a major complication had a mean nephrometry score of 8.1 ± 2.0 vs 6.8 ± 1.9 (p <0.001). CONCLUSIONS The R.E.N.A.L. nephrometry scoring system predicts treatment efficacy and complications following percutaneous renal ablation.

Motor Evoked Potential Monitoring during Cryoablation of Musculoskeletal Tumors

PURPOSE To describe the use of intraprocedural motor evoked potential (MEP) monitoring to minimize risk of neural injury during percutaneous cryoablation of perineural musculoskeletal tumors. MATERIALS AND METHODS A single-institution retrospective review of cryoablation procedures performed to treat perineural musculoskeletal tumors with the use of MEP monitoring between May 2011 and March 2013 yielded 59 procedures to treat 64 tumors in 52 patients (26 male). Median age was 61 years (range, 4-82 y). Tumors were located in the spine (n = 27), sacrum (n = 3), retroperitoneum (n = 4), pelvis (n = 22), and extremities (n = 8), and 21 different tumor histologies were represented. Median tumor size was 4.0 cm (range, 0.8-15.0 cm). Total intravenous general anesthesia, computed tomographic guidance, and transcranial MEP monitoring were employed. Patient demographics, tumor characteristics, MEP findings, and clinical outcomes were assessed. RESULTS Nineteen of 59 procedures (32%) resulted in decreases in intraprocedural MEPs, including 15 (25%) with transient decreases and four (7%) with persistent decreases. Two of the four patients with persistent MEP decreases (50%) had motor deficits following ablation. No functional motor deficit developed in a patient with transient MEP decreases or no MEP change. The risk of major motor injury with persistent MEP changes was significantly increased versus transient or no MEP change (P = .0045; relative risk, 69.8; 95% confidence interval, 5.9 to > 100). MEP decreases were 100% sensitive and 70% specific for the detection of motor deficits. CONCLUSIONS Persistent MEP decreases correlate with postprocedural sustained motor deficits. Intraprocedural MEP monitoring helps predict neural injury and may improve patient safety during cryoablation of perineural musculoskeletal tumors.

Percutaneous cryoablation of solitary sporadic renal cell carcinomas

Study Type – Therapy (case series)

Cryoablation of Recurrent Sacrococcygeal Tumors

PURPOSE To review the safety and efficacy of cryoablation of recurrent sacrococcygeal tumors. MATERIALS AND METHODS The radiology departmental ablation database was retrospectively searched for cases of cryoablation performed to treat recurrences of sacrococcygeal tumors between January 1, 2010, and August 1, 2011. Patient demographics, procedure technical parameters, and patient outcomes were reviewed. RESULTS Five cases of recurrent chordoma and one recurrent myxopapillary ependymoma were treated with cryoablation in six patients whose ages ranged from 31 to 80 years. The tumors measured 14-39 mm in maximal dimension. Cryoablation was performed with the use of computed tomography guidance (n = 5) or a combination of ultrasound and magnetic resonance imaging guidance (n = 1). Sterile fluid was instilled to displace adjacent bowel and/or vagina in four cases, and electromyography monitoring was performed in two cases with adjacent nerve roots. Two patients with recurrent chordoma were treated for palliation of pain, with complete pain relief in one patient (pain recurred after 6 wk) and immediate reduction in pain from a score of six to a score of two on a 10-point scale in the other (pain recurred after 7 mo). Four tumors were treated for local control, with no evidence of recurrence on follow-up imaging at 3, 6, 12, and 15 months. No serious complication occurred. CONCLUSIONS Limited results suggest cryoablation to be a safe and relatively effective means of treating recurrent sacrococcygeal neoplasms for local control or palliation of pain in this small series with short-term follow-up.

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 Cryoablation of Anterior Renal Masses: Technique, Efficacy, and Safety

OBJECTIVE The safety and efficacy of renal tumor ablation are related, in part, to tumor location. Anterior tumors present a challenge due to the risk of injury to adjacent structures. The purpose of this study was to review the techniques, complications, and short-term outcomes of percutaneous cryoablation of anterior renal masses at a single institution. MATERIALS AND METHODS We retrospectively identified the cases of 35 patients with 38 anterior renal masses managed with percutaneous imaging-guided cryoablation of renal tumors from March 2003 through February 2009. The technical success of the ablation procedure, serious complications, and evidence of local tumor recurrence were evaluated for each patient. RESULTS The average maximal diameter of the anterior renal masses was 2.9 cm (SD, 0.9 cm; range, 1.4-4.8 cm). A single cryoablation procedure was performed for treatment of each patient, and technically successful ablation was achieved for all 38 tumors. A single severe adverse event occurred in one of the 35 patients (3% major complication rate). This patient had a pulmonary embolism (diagnosed at CT angiography the day after ablation). He recovered and was discharged from the hospital with anticoagulant medication only 2 days after the procedure. No local tumor recurrence was identified in any of the 29 patients who underwent follow-up contrast-enhanced CT or MRI with images available for review 3 months or longer from the time of ablation (mean, 18 months; range, 3-45 months). CONCLUSION Percutaneous cryoablation of anterior renal masses can be performed with high technical success and low complication rates. The lack of local renal tumor recurrence at short-term follow-up evaluation in this study is encouraging, but long-term follow-up is necessary to ensure the durability of treatment.

Ablation of Musculoskeletal Metastases: Pain Palliation, Fracture Risk Reduction, and Oligometastatic Disease

Thermal ablation is an effective, minimally invasive alternative to conventional therapies in the palliation of painful musculoskeletal metastases and an emerging approach to obtain local tumor control in the setting of limited metastatic disease. Various thermal ablation technologies have been applied to bone and soft tissue tumors and may be used in combination with percutaneous cement instillation for skeletal lesions with or at risk for pathologic fracture. This article reviews current practices of percutaneous ablation of musculoskeletal metastases with an emphasis on radiofrequency ablation and cryoablation of painful skeletal metastases.

Renal oncocytoma growth rates before intervention

Study Type – Prognosis (case series)

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.

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.