Grant D. Schmit

Comparison of partial nephrectomy and percutaneous ablation for cT1 renal masses.

BACKGROUND Partial nephrectomy (PN) is a preferred treatment for cT1 renal masses, whereas thermal ablation represents an alternative nephron-sparing option, albeit with higher reported rates of recurrence. OBJECTIVE To review our experience with PN, percutaneous radiofrequency ablation (RFA), and percutaneous cryoablation for cT1 renal masses. DESIGN, SETTING, AND PARTICIPANTS A total of 1803 patients with primary cT1N0M0 renal masses treated between 2000 and 2011 were identified from the prospectively maintained Mayo Clinic Renal Tumor Registry. INTERVENTION PN compared with percutaneous ablation. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Local recurrence-free, metastases-free, and overall survival rates were estimated using the Kaplan-Meier method and compared with log-rank tests. RESULTS AND LIMITATIONS Of the 1424 cT1a patients, 1057 underwent PN, 180 underwent RFA, and 187 underwent cryoablation. In this cohort, local recurrence-free survival was similar among the three treatments (p=0.49), whereas metastases-free survival was significantly better after PN (p=0.005) and cryoablation (p=0.021) when compared with RFA. Of the 379 cT1b patients, 326 patients underwent PN, and 53 patients were managed with cryoablation (8 RFA patients were excluded). In this cohort, local recurrence-free survival (p=0.81) and metastases-free survival (p=0.45) were similar between PN and cryoablation. In both the cT1a and cT1b groups, PN patients were significantly younger, with lower Charlson scores and had superior overall survival (p<0.001 for all). Limitations include retrospective review and selection bias. CONCLUSIONS In a large cohort of sporadic cT1 renal masses, we observed that recurrence-free survival was similar for PN and percutaneous ablation patients. Metastases-free survival was superior for PN and cryoablation patients when compared with RFA for cT1a patients. Overall survival was superior after PN, likely because of selection bias. If these results were validated, an update to clinical guidelines would be warranted. PATIENT SUMMARY Partial nephrectomy and percutaneous ablation for small (<7-cm) and localized renal masses are associated with similar rates of local recurrence.

Percutaneous image-guided cryoablation of painful metastases involving bone: multicenter trial.

This study sought to describe the results of a single‐arm multicenter clinical trial using image‐guided percutaneous cryoablation for the palliation of painful metastatic tumors involving bone.

Complications following 573 Percutaneous Renal Radiofrequency and Cryoablation Procedures

PURPOSE To review complications related to percutaneous renal tumor ablation. MATERIALS AND METHODS Prospectively collected data related to renal radiofrequency (RF) ablation and cryoablation procedures performed from May 2000 through November 2010 were reviewed. This included 573 renal ablation procedures performed in 533 patients to treat 633 tumors. A total of 254 RF ablation and 311 cryoablation procedures were performed; eight patients underwent simultaneous RF ablation and cryoablation. The mean age of patients at the time of the procedure was 70 years (range, 24-93 y), and 382 of 573 procedures (67%) were performed in male patients. Complications were recorded according to the Clavien-Dindo classification scheme. Duration of hospitalization was also documented. RESULTS Of the 573 procedures, 63 produced complications (11.0% overall complication rate). There were 66 reported complications, of which 38 (6.6% of total procedures) were Clavien-Dindo grade II-IV major complications; there were no deaths. Major complication rates did not differ statistically (P = .15) between cryoablation (7.7%; 24 of 311) and RF ablation (4.7%; 12 of 254). Of the complications related to cryoablation, bleeding and hematuria were most common. Bleeding during cryoablation was associated with advanced age, increased tumor size, increased number of cryoprobes, and central position (P < .05). Of those treated with RF ablation, nerve and urothelial injury were most common. Mean hospitalization duration was 1 day for RF ablation and cryoablation. CONCLUSIONS Complications related to percutaneous renal ablation are infrequent. Recognition of potential complications and associated risk factors can allow optimization of periprocedural care.

Sarcopenia in patients with bladder cancer undergoing radical cystectomy: Impact on cancer‐specific and all‐cause mortality

The authors evaluated sarcopenia as a predictor of cancer‐specific survival (CSS) and overall survival (OS) among patients with urothelial cancer of the bladder undergoing radical cystectomy (RC).

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.

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 Renal Cryoablation: Local Control at Mean 26 Months of Followup

PURPOSE We retrospectively determined the efficacy of percutaneous renal cryoablation based on a mean followup of more than 2 years. MATERIALS AND METHODS Institutional review board approval was obtained for this Health Insurance Portability and Accountability Act compliant retrospective study. Informed consent was waived. From March 2003 through March 2007, 91 patients with 93 tumors underwent 92 percutaneous cryoablation procedures. Technical success was defined as extension of the ice ball beyond the tumor margin and post-ablation images showing no contrast enhancement in the area encompassing the original tumor within 3 months of the procedure. Local tumor progression was defined as new enhancement in the ablated tumor or an increase in ablated tumor size beyond 3 months after the procedure. Complications were defined using the National Cancer Institute Common Terminology Criteria for Adverse Events v3.0. RESULTS Mean followup was 26 months (range 5 to 61, SD ±13) and mean tumor size was 3.4 cm (range 1.5 to 7.3, SD ±1.2). Major complications occurred in 6 of 91 patients (7%) or after 8 of 92 (9%) procedures. Technically successful ablation was performed in the treatment of 89 of the 93 (96%) tumors or 87 of the 91 patients (96%). Of the 83 tumors with followup longer than 3 months only a single case (1%) of local tumor progression occurred. Overall local control was achieved in 86 of 91 (95%) patients or 88 of 93 (95%) tumors. CONCLUSIONS Midterm followup of percutaneous renal cryoablation shows durability of this treatment method with a low incidence of tumor recurrence beyond 3 months.

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.

CT findings of walled-off pancreatic necrosis (WOPN): differentiation from pseudocyst and prediction of outcome after endoscopic therapy

Computed tomography (CT) findings that may differentiate walled-off pancreatic necrosis (WOPN) from pancreatic pseudocyst were investigated. CT examinations performed before endoscopic therapy of pancreatic fluid collection (PFC) in 73 patients (45 WOPN, 28 pseudocysts) were evaluated retrospectively by two radiologists. PFC was evaluated for size, extension to paracolic space, characteristics of wall and internal structure. The pancreas was evaluated for deformity or discontinuity, and pancreatic duct dilation. CT findings that were associated with WOPN or pseudocyst were identified. CT score (number of CT findings associated with WOPN minus number of findings associated with pseudocyst) was calculated for each PFC. PFC was categorized as WOPN or pseudocyst using a CT score threshold. Larger size, extension to paracolic space, irregular wall definition, presence of fat attenuation debris in PFC, pancreatic deformity or discontinuity (P < 0.05–0.0001) were findings associated with WOPN. Presence of pancreatic duct dilation was associated with pseudocyst. Using a CT score of 2 or higher as a threshold, CT differentiated WOPN from pseudocyst with an accuracy of 79.5–83.6%. Thus, CT can differentiate WOPN from pseudocysts.

Hydrodisplacement in the Percutaneous Cryoablation of 50 Renal Tumors

OBJECTIVE The purpose of this article is to describe the technique, safety, and effectiveness of percutaneous hydrodisplacement during the course of percutaneous renal cryoablation. MATERIALS AND METHODS We retrospectively reviewed our experience in performing percutaneous hydrodisplacement during the cryoablation of renal tumors. In this subset of patients, we addressed tumor location within the kidney, tumor position relative to critical structures, effectiveness of hydrodisplacement, and complications in performing this adjunct technique. Comparisons between the two groups were made using Wilcoxons rank sum test or chi-square test, as appropriate. RESULTS Hydrodisplacement was attempted 52 times in 50 (24%) of 206 percutaneous renal tumor cryoablations. Tumors that were located anteriorly (p < 0.0001) or in the lower pole (p = 0.001) of the kidney were more likely to require hydrodisplacement. The colon required displacement most often (n = 41), followed by the body wall (n = 3), duodenum (n = 2), jejunum and ileum (n = 2), ureter (n = 1), and psoas muscle (n = 1). There was a single complication of hemorrhage resulting from injury to an intercostal artery branch that required termination of the procedure before fluid infusion. When fluid was infused, the critical structure was displaced in 50 (96%) of 52 attempts, displacing the critical structure from its initial location by a mean distance of 16 mm (range, 3-46 mm). Both failures occurred early in our experience with hydrodisplacement, and both required balloon displacement. CONCLUSION Hydrodisplacement is a safe, effective, and commonly needed technique for displacement of critical structures before percutaneous cryoablation of renal tumors, particularly for tumors located anteriorly or in the lower pole of the kidney.