- Email: [email protected]
PD46-02 INITIAL CLINICAL EXPERIENCE WITH PERCUTANEOUS IRREVERSIBLE ELECTROPORATION OF RENAL TUMORS
Vol. 195, No. 4S, Supplement, Tuesday, May 10, 2016
treatment option for the management of small renal cortical neoplasms. Given the current guidelines to limit an individual’s annual radiation exposure to under 50 mSv/year, we developed a hybrid technique using ultrasound (US) as an adjunct imaging modality to limit the radiation exposure of our patients. Herein, we compare CT guided (CTG) and ultrasound-facilitated CT guided (US-CTG) percutaneous cryoablation of renal cortical neoplasms. METHODS: We retrospectively analyzed patients undergoing PCA at our institution between February 2012 and October 2015. Patients were divided into two groups based on the type of imaging used during the PCA. Demographic data and tumor characteristics were compared. Total dose-length product (DLP) for the procedure was recorded and subsequently converted to estimated dose (ED). For USCTG, initial cryoprobe deployments were done under US guidance. CT scout and planning images confirmed needle placement and were then used for probe adjustments. For CTG PCA, probe placement and positioning were done using only real-time CT fluoroscopy. RESULTS: A total of 25 patients underwent PCA (12 US-CTG and 13 CTG). There was no difference with regard to patient demographics and tumor characteristics (Table 1); however, there was a higher proportion of biopsy-proven renal cell carcinoma (RCC) in the US-CTG group. There were no differences in mean operative time (p ¼ 0.928), and all operations were technically successful. The total radiation ED was significantly lower with US-CTG compared to CTG PCA (16.0 vs. 22.3 mSv, respectively; p ¼ 0.018). There was 1 complication of post-operative bleeding (US-CTG) in a patient with an occult coagulopathy, which became apparent following the PCA and led to subsequent angiography and embolization. There was only one nondiagnostic biopsy (CTG). One patient (US-CTG) with a complex endophytic RCC was found to have residual disease on follow up imaging. CONCLUSIONS: With short-term follow-up, US-CTG cryoablation of small renal cortical neoplasms significantly reduces radiation exposure for both patients and clinicians without altering operative times or patient outcomes.
THE JOURNAL OF UROLOGYâ
within cellular membranes resulting in subsequent apoptosis. Because IRE is athermal, it offers potential advantages to radiofrequency (RFA) and cryoablation. We evaluated our initial experience to assess feasibility, safety, effectiveness, and radiographic outcomes of IRE renal tumor ablation. METHODS: We retrospectively reviewed all IRE cases completed at our institution from April 2013-July 2015. IRE was performed using the NanoKnifeâ commercial system and 15 cm monopolar probes (AngioDynamics, NY, USA). All procedures were performed with computed tomography (CT) guidance, under general anesthesia with paralytics, and with ablation synchronized to the cardiac cycle. A minimum of six weeks of follow-up with a contrast-enhanced CT scan was necessary to be included in the analysis. RESULTS: A total of 32 tumors were treated with IRE, with median follow up of 10 months (range 1-27 months). Patient and tumor characteristics are shown in table 1. CT scan immediately post procedure typically showed decreased perfusion with an enhancing rim at the ablation site. Patients were discharged the same day in 20 of 32 (63%) cases, while the remainder were discharged on the first post-operative day. There were no complications. At six weeks, three patients (9.4%) had persistent rim enhancement on CT scan, indicating ablation failure. These patients underwent successful salvage RFA and remain disease free. Of 21 patients with at least six months of follow up, one patient (4.8%) had a recurrence that was treated with successful partial nephrectomy. CONCLUSIONS: Percutaneous IRE of renal tumors is feasible and safe. Nephron-sparing techniques remain a viable salvage option in patients who fail IRE. Further follow-up is needed to demonstrate longterm oncologic efficacy.
Source of Funding: none
PD46-02 INITIAL CLINICAL EXPERIENCE WITH PERCUTANEOUS IRREVERSIBLE ELECTROPORATION OF RENAL TUMORS Noah Canvasser*, Aaron Lay, Monica Morgan, Asim Ozayar, Jeffrey Gahan, Clayton Trimmer, Jeffrey Cadeddu, Dallas, TX INTRODUCTION AND OBJECTIVES: Percutaneous irreversible electroporation (IRE) is a novel minimally invasive technique to treat small renal tumors. IRE uses an electric field to create nano-pores
e1123
Source of Funding: None
treatment option for the management of small renal cortical neoplasms. Given the current guidelines to limit an individual’s annual radiation exposure to under 50 mSv/year, we developed a hybrid technique using ultrasound (US) as an adjunct imaging modality to limit the radiation exposure of our patients. Herein, we compare CT guided (CTG) and ultrasound-facilitated CT guided (US-CTG) percutaneous cryoablation of renal cortical neoplasms. METHODS: We retrospectively analyzed patients undergoing PCA at our institution between February 2012 and October 2015. Patients were divided into two groups based on the type of imaging used during the PCA. Demographic data and tumor characteristics were compared. Total dose-length product (DLP) for the procedure was recorded and subsequently converted to estimated dose (ED). For USCTG, initial cryoprobe deployments were done under US guidance. CT scout and planning images confirmed needle placement and were then used for probe adjustments. For CTG PCA, probe placement and positioning were done using only real-time CT fluoroscopy. RESULTS: A total of 25 patients underwent PCA (12 US-CTG and 13 CTG). There was no difference with regard to patient demographics and tumor characteristics (Table 1); however, there was a higher proportion of biopsy-proven renal cell carcinoma (RCC) in the US-CTG group. There were no differences in mean operative time (p ¼ 0.928), and all operations were technically successful. The total radiation ED was significantly lower with US-CTG compared to CTG PCA (16.0 vs. 22.3 mSv, respectively; p ¼ 0.018). There was 1 complication of post-operative bleeding (US-CTG) in a patient with an occult coagulopathy, which became apparent following the PCA and led to subsequent angiography and embolization. There was only one nondiagnostic biopsy (CTG). One patient (US-CTG) with a complex endophytic RCC was found to have residual disease on follow up imaging. CONCLUSIONS: With short-term follow-up, US-CTG cryoablation of small renal cortical neoplasms significantly reduces radiation exposure for both patients and clinicians without altering operative times or patient outcomes.
THE JOURNAL OF UROLOGYâ
within cellular membranes resulting in subsequent apoptosis. Because IRE is athermal, it offers potential advantages to radiofrequency (RFA) and cryoablation. We evaluated our initial experience to assess feasibility, safety, effectiveness, and radiographic outcomes of IRE renal tumor ablation. METHODS: We retrospectively reviewed all IRE cases completed at our institution from April 2013-July 2015. IRE was performed using the NanoKnifeâ commercial system and 15 cm monopolar probes (AngioDynamics, NY, USA). All procedures were performed with computed tomography (CT) guidance, under general anesthesia with paralytics, and with ablation synchronized to the cardiac cycle. A minimum of six weeks of follow-up with a contrast-enhanced CT scan was necessary to be included in the analysis. RESULTS: A total of 32 tumors were treated with IRE, with median follow up of 10 months (range 1-27 months). Patient and tumor characteristics are shown in table 1. CT scan immediately post procedure typically showed decreased perfusion with an enhancing rim at the ablation site. Patients were discharged the same day in 20 of 32 (63%) cases, while the remainder were discharged on the first post-operative day. There were no complications. At six weeks, three patients (9.4%) had persistent rim enhancement on CT scan, indicating ablation failure. These patients underwent successful salvage RFA and remain disease free. Of 21 patients with at least six months of follow up, one patient (4.8%) had a recurrence that was treated with successful partial nephrectomy. CONCLUSIONS: Percutaneous IRE of renal tumors is feasible and safe. Nephron-sparing techniques remain a viable salvage option in patients who fail IRE. Further follow-up is needed to demonstrate longterm oncologic efficacy.
Source of Funding: none
PD46-02 INITIAL CLINICAL EXPERIENCE WITH PERCUTANEOUS IRREVERSIBLE ELECTROPORATION OF RENAL TUMORS Noah Canvasser*, Aaron Lay, Monica Morgan, Asim Ozayar, Jeffrey Gahan, Clayton Trimmer, Jeffrey Cadeddu, Dallas, TX INTRODUCTION AND OBJECTIVES: Percutaneous irreversible electroporation (IRE) is a novel minimally invasive technique to treat small renal tumors. IRE uses an electric field to create nano-pores
e1123
Source of Funding: None