Publications (11)28.34 Total impact
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Article: Comparison of biochemical failure definitions for predicting local cancer recurrence following cryoablation of the prostate.
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ABSTRACT: Various definitions of biochemical failure (BF) have been used to predict cancer recurrence following prostate cryoablation. However to date, none of these definitions have been validated for this use. We have reviewed several definitions of BF to determine their accuracy in predicting biopsy-proven local recurrence following prostate cryoablation. The Columbia University Urologic Oncology Database was queried for patients who underwent prostate cryoablation between 1994 and 2010, and who subsequently underwent surveillance biopsy due to clinical suspicion of prostate cancer recurrence. Serial postoperative prostate-specific antigen (PSA) results were used to determine BF according to various definitions of BF. Biopsy results were used to determine local recurrence. Sensitivity, specificity, positive and negative predictive value, and receiver operating characteristic (ROC) curve area were calculated for each of the BF definitions. A total of 110 patients met inclusion criteria for the study. These patients were treated with primary full-gland (n = 38), primary focal (n = 24), or salvage cryoablation (n = 48). On surveillance biopsy, 66 patients (60%) were found to have locally recurrent prostate cancer. The most accurate BF definition overall was PSA nadir plus 2 ng/ml (Phoenix definition), with sensitivity, specificity, and ROC curve area of 68%, 59%, and 0.64, respectively. Overall, the Phoenix definition best predicted local cancer recurrence following prostate cryoablation. These preliminary data may be useful for researchers evaluating the short-term efficacy of cryoablation, and for urologists assessing their patients for potential cancer recurrence. Prostate 72:1802-1808, 2012. © 2012 Wiley Periodicals, Inc.The Prostate 05/2012; 72(16):1802-8. · 3.48 Impact Factor -
Article: Evaluation of preoperative bioimpedance spectroscopy quantification of body composition on predicting postoperative outcomes following robotic assisted radical prostatectomy (RARP).
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ABSTRACT: Bioimpedance spectroscopy (BIS) is a novel, precise quantification of body composition (BC) using low electrical currents through tissue. Accurate BC quantification may better predict postoperative outcomes. We compared BIS-BC and body mass index (BMI) for correlation with post-surgical outcomes in robotic assisted radical prostatectomy (RARP) patients. Preoperative BIS-BC and BMI analyses were conducted on men with biopsy-proven prostate cancer undergoing RARP. Height, weight, percentage and fat mass (PFM, FM), percentage and fat-free mass (PFFM, FFM), percentage and total body water (PTBW, TBW), and percentage and intracellular/extracellular water (PICW, PECW, ICW, ECW) were obtained using the ImpediMed SFB7 Device (San Diego, CA, USA). Preoperative PSA, biopsy and pathologic Gleason scores, prostate volume, percentage tumor volume, margin status, operative time, estimated blood loss (EBL) and pathologic stage were recorded. Spearman's rank correlation was estimated to evaluate the association between BIS-BC results, BMI, and post-surgical outcomes. Between April 2009 and August 2010, 63 men had been enrolled in this ongoing study. Fourteen were of normal weight (18.5 kg/m2-24.9 kg/m2), 33 were overweight (25 kg/m2-29.9 kg/m2) and 16 were obese (BMI ≥ 30 kg/m2). Mean age was 60.7 years, mean preoperative PSA was 7.4 ng/mL, and median Gleason was 7. BMI correlated with FFM (p = 0.002), FM (p = 0.01), and PTBW (p = 0.02). FM correlated with preoperative PSA (p = 0.01). PFFM (p = 0.03), PFM (p = 0.03) and PTBW (p = 0.04) correlated with % tumor volume. ICW (p = 0.01) and TBW (p = 0.009) correlated with EBL. BMI (p = 0.04), PECW (p = 0.04), FM (p = 0.05), and PICW (p = 0.03) correlated with pathologic tumor stage. BMI correlates with BIS-BC FFM, FM and PTBW. PFFM, PFM and PTBW correlated with % tumor volume. ICW and TBW correlated with EBL. BMI, PECW, FM, and PICW correlated with pathologic tumor stage. BIS-BC metrics may be helpful in predicting post-RARP outcomes. Further study is required to validate these predictions.The Canadian Journal of Urology 12/2011; 18(6):6031-6. · 0.64 Impact Factor -
Article: BioGlue iceball stabilization to minimize the risk of hemorrhage during laparoscopic renal cryoablation.
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ABSTRACT: To evaluate the application of a BioGlue adhesive shell to minimize iceball fracture. Iceball fracture and hemorrhage is common with laparoscopic cryoablation (LCA) of larger (>4 cm) renal tumors. Twenty large iceballs were created in porcine kidneys using 3 cryoablation probes in a nonsurvival study. Each kidney underwent an upper and lower pole ablation. One pole in each kidney was covered with 5 mL of BioGlue and the opposite pole served as a control. A double freeze-thaw cycle was performed (10 minutes freeze and 5 minutes active thaw) in both renal poles simultaneously. The probes were removed and the sites were monitored for 20 minutes under direct vision. Fracture length (mm), severity of fracture depth, severity of bleeding (absent, mild, moderate, severe), and estimated blood loss (EBL) (mL) were recorded. In the control group, the mean fracture length was 1.9 mm (range, 0-3 mm). Blood loss was absent in 10%, mild in 60%, and moderate in 30% of ablations. The mean EBL was 20.5 mL (range, 0-50 mL). For the BioGlue ablations, there were no parenchymal fractures. Blood loss was mild in 30% and absent in 70% of sites with an average EBL of 5 mL (range, 0-20). Two bleeding sites occurred as a result of subcapsular hematomas caused by initial probe placement. BioGlue application minimized the frequency and magnitude of renal fracture. EBL was lower with BioGlue application and most sites demonstrated no postablation bleeding. Further clinical study of the BioGlue shell should be performed to confirm these results.Urology 08/2011; 78(2):353-6. · 2.43 Impact Factor -
Article: Impact of HMG-CoA reductase inhibitor (statin) use on blood loss during robot-assisted and open radical prostatectomy.
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ABSTRACT: In addition to their lipid lowering effects, HMG-CoA reductase inhibitors (statins) have been shown to exert antithrombotic effects through downregulation of the coagulation cascade. Because statin use is widespread, it is important to understand the impact of these drugs on blood loss (BL) during surgery. We studied the impact of statin use on BL during robot-assisted radical prostatectomy (RARP) and open radical prostatectomy (ORP). A retrospective review was conducted of a database approved by the Institutional Review Board for patients who underwent RARP or ORP at a single academic institution. Patients were categorized as statin-users or statin-naïve at the time of surgery. Patient demographic information was recorded as was perioperative data, including preoperative and postoperative hematocrit (Hct) value. BL was defined as % Hct change presurgery vs postsurgery. In addition, the outcome of ≥10% drop in Hct was studied. The t test and chi-square analysis were used to compare variables across statin use groups. Univariate and multivariable logistic regression analyses were used to identify factors that impacted BL. From 1987 to 2010, 3578 patients underwent prostatectomy for prostate cancer (RARP=945 and ORP=2633). Of these, 676 men were identified as statin-users and 2902 as statin-naïve. Mean patient age was 60.2±7.0 years. Statin-users were found to be older (P<0.001), have lower mean preoperative prostate-specific antigen (PSA) levels (P=0.002), and have higher pathologic Gleason sum scores (P<0.001). For ORP, statin use was associated with increased BL with Hct % change of 20.7% for users vs18.6% for nonusers, (P<0.001). For RARP, no significant change in Hct was seen with statin use with % changes of 12.6% and 12.5%, respectively (P=0.9). When controlling for age, Gleason sum, surgeon, date of surgery and PSA level, statin use was associated with increased BL (P=0.04). Even when controlling for age, Gleason sum, surgeon, date of surgery, and PSA, statin use is associated with increased BL during RP. This information may impact preoperative planning and patient counseling for men who are taking statins while preparing for RP.Journal of endourology / Endourological Society 07/2011; 25(9):1427-33. · 1.75 Impact Factor -
Article: Gleason score concordance on biopsy-confirmed prostate cancer: is pathological re-evaluation necessary prior to radical prostatectomy?
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ABSTRACT: • Gleason sum from prostate biopsy (bGS) is an important tool in classifying severity of disease, ultimately influencing clinical management. • Commonly, pathology specimens are re-evaluated internally prior to surgery. • We evaluate agreement of bGS with prostatectomy Gleason sum (pGS) and the impact of re-grading on prediction of true underlying tumor architecture. • Retrospective analysis of men who underwent robotic-assisted radical prostatectomy (RARP) by two surgeons from 2005-2009. Initial transrectal ultrasound (TRUS) biopsy demonstrated carcinoma at an outside lab. Specimens were re-evaluated by our GU pathologists prior to surgery. Biopsy data were correlated with pGS. • Kappa (κ) statistics for agreement and linear regression analyses were used for categorical variables. Coefficient of concordance was used for continuous variables. • 100 patients had 331 positive biopsies. Agreement (κ) for bGS between outside labs and our pathologists was 0.55 (p < 0.001). • Internal read was twice as likely to upgrade vs. downgrade outside bGS (23% vs. 11%). • When re-evaluation resulted in a change in bGS, agreement with pGS was κ= 0.29, vs. κ=-0.04 for agreement of initial (outside) bGS with pGS. • When no change was made to bGS, agreement with pGS was κ= 0.40 (p < 0.001). • Good reproducibility seen between outside labs and our institution on bGS. Internal pathology re-reads correlated better with pGS than original community bGS. When re-reads result in a change in bGS, there is a marked improvement in prediction of underlying tumor architecture confirming the value of re-evaluating all external biopsies prior to definitive surgery.BJU International 03/2011; 107(5):749-54. · 2.84 Impact Factor -
Article: Impacting factors for recovery of erectile function within 1 year following robotic-assisted laparoscopic radical prostatectomy.
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ABSTRACT: Neurovascular bundle preservation generally results in good postoperative sexual function after radical prostatectomy. However, erectile function (EF) after radical prostatectomy is still a significant concern. The same surgical technique often results in different EF outcomes. We evaluated factors that correlate with recovery of EF within 1 year after robotic-assisted laparoscopic radical prostatectomy (RALP). From January 2008 to May 2009, 145 consecutive patients underwent RALP by one surgeon. Patients were followed postoperatively at 3-month intervals and assessed for EF recovery, defined as an erection sufficient for penetrative intercourse with satisfaction. Baseline demographics, medical comorbidities, degree of nerve sparing, and perioperative and postoperative variables were recorded. Univariate and multivariate analyses were used to determine factors associated with EF recovery. Postoperative sexual outcomes were attained prospectively via our erectile state questionnaire. Complete follow-up EF data were available on 89 men. Within 1-year follow-up, 56 men (62.9%) recovered EF and 33 men (37.1%) did not. In univariate logistic regression analysis, race (black), diabetes mellitus, hyperlipidemia, and clinical T2 carcinoma of the prostate were associated with diminished EF. Higher-preoperative Sexual Health Inventory for Men score and incremental nerve sparing (enhanced lateral prostatic fascia sparing) were associated with higher odds of recovering potency. In multivariate analysis, hyperlipidemia was primary comorbidity associated with diminished EF, and bilateral nerve sparing with a minimum unilateral-enhanced status was the impacting factor for EF recovery within 1 year after surgery. Bilateral nerve preservation with a minimum unilateral-enhanced status is associated with improved recovery of EF, and hyperlipidemia is a significant negative predictive factor of postoperative EF recovery within 1 year following RALP. Therefore, it is important to control hyperlipidemia as well as to use the proper surgical technique in maximizing EF recovery within 1 year after radical prostatectomy.Journal of Sexual Medicine 03/2011; 8(6):1805-12. · 3.55 Impact Factor -
Article: Use of a flexible carbon dioxide laser fiber for precise dissection of the neurovascular bundle during robot-assisted laparoscopic prostatectomy.
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ABSTRACT: Carbon dioxide (CO(2)) lasers deliver energy with minimal thermal spread to tissues during dissection. Excess thermal spread during dissection of the neurovascular bundle (NVB) can affect potency in men after robot-assisted radical prostatectomy (RARP). We report on a novel delivery mechanism for CO(2) laser energy through a flexible fiber to enhance accuracy of NVB dissection during RARP. A feasibility study of the OmniGuide BeamPath URO-LG CO(2) laser fiber for NVB dissection was performed on 10 patients with primary Gleason 3 T1c prostate cancer during RARP. Bilateral lateral fascial antegrade nerve sparing was performed. We evaluated fiber performance, safety, and efficacy. The fiber was inserted through the 12-mm assistant's port and easily manipulated by robotic instruments. Once pedicles were clipped and dissected, the laser fiber was effective in establishing planes of dissection between prostatic capsule and NVB. The endoscopically discernable thermal laser footprint was small, with minimal thermal spread during nerve sparing, meticulous dissection of NVB, and fascial layer identification. Although the laser did provide extremely accurate dissection, it was unable to serve as an adequate means of larger vessel coagulation. The flexible CO(2) laser fiber was easily manipulated. Identification of fascial layers during nerve sparing was facilitated with the fiber. Long-term follow-up is necessary to determine efficacy of this technology versus conventional techniques on the NVB. Larger studies are currently in progress to determine if use of the flexible CO(2) laser fiber results in improvements in functional outcomes with regard to return of sexual potency after RARP.Journal of endourology / Endourological Society 07/2010; 24(7):1091-6. · 1.75 Impact Factor -
Article: Assessment of lymph node yield after pelvic lymph node dissection in men with prostate cancer: a comparison between robot-assisted radical prostatectomy and open radical prostatectomy in the modern era.
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ABSTRACT: Studies of radical prostatectomy (RP) suggest that higher lymph node yield (LNY) improves tumor staging. Robot-assisted radical prostatectomy (RARP) is becoming increasingly popular, yet LNY data are not well reported. We compare LNY from contemporary open RP (ORP) with RARP at an academic center. A retrospective study was conducted of an Urologic Oncology Database. Between January 2005 and November 2009, 217 men underwent ORP with pelvic lymph node dissection (PLND); 99 underwent RARP with PLND by a single surgeon during the same period. Men were stratified according to the D'Amico risk criteria. For intermediate and high-risk disease, an extended PLND was performed. Patient demographic, operative, and pathologic variables were measured, and LNY was compared across groups. No significant differences were seen between groups for race, body mass index, preoperative prostate-specific antigen level or biopsy Gleason score. Patients were younger for RARP vs ORP (P = 0.003) and had higher clinical tumor stage (P = 0.02). Operative time was longer (P = 0.03) and estimated blood loss was greater (P < 0.001) in the ORP group. Overall, only a borderline significant difference was seen in LNY between ORP and RARP (7.49 vs 6.35 nodes, respectively, P = 0.06). No difference was seen for intermediate and high-risk patients, with 7.7 vs 6.8 nodes for ORP and RARP, respectively (P = 0.27). The lymph node metastasis rate was 6.3%, with more positive nodes detected during ORP vs RARP: 19/217 (8.8%) vs 1/99 (1.0%), P = 0.009. No significant differences were seen in LNY during RARP and ORP for intermediate and high-risk men. For experienced surgeons, RARP can achieve equivalent LNY as ORP. A future study with a larger sample size is necessary to make a definitive statement of equivalence.Journal of endourology / Endourological Society 07/2010; 24(7):1055-60. · 1.75 Impact Factor -
Article: Differential heart rate response to magnetic seizure therapy (MST) relative to electroconvulsive therapy: a nonhuman primate model.
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ABSTRACT: Electroconvulsive therapy (ECT) is an effective treatment for severe depression; however, the induced therapeutic seizure acts on the autonomic nervous system and results in significant cardiac effects. This is an important consideration particularly in the elderly. Magnetic seizure therapy (MST) is in development as a less invasive alternative, but its effects on cardiac function have not been studied. We sought to model those effects in nonhuman primates to inform the development of safer neurostimulation interventions. Twenty four rhesus monkeys were randomly assigned to receive 6 weeks of daily treatment with electroconvulsive stimulation (ECS), magnetic seizure therapy (MST) or anesthesia-alone sham. Digitally acquired ECG and an automated R-wave and inter-R interval (IRI) sampling were used to measure intervention effects on heart rate (HR). Significant differences between experimental conditions were found in the HR as evidenced by changes in the immediate post-stimulus, ictal and postictal epochs. Immediate post-stimulus bradycardia was seen with ECS but not with MST. ECS induced significantly more tachycardia than MST or sham in both the ictal and postictal periods. MST resulted in a small, but statistically significant increase in HR during the postictal period relative to baseline. HR was found to increase by 25% and 8% in the ECS and MST conditions, respectively. MST resulted in significantly less marked sympathetic and parasympathetic response than did ECS. This differential physiological response is consistent with MST having a more superficial cortical site of action with less impact on deeper brain structures implicated in cardiac control relative to ECT. The clinical relevance of the topographical seizure spread of MST and its associated effects on the autonomic nervous system remain to be determined in human clinical trials.NeuroImage 07/2009; 47(3):1086-91. · 5.89 Impact Factor -
Article: Comparison of two core biopsy techniques before and after laparoscopic cryoablation of small renal cortical neoplasms.
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ABSTRACT: Cryoablation is an acceptable treatment option for small renal cortical neoplasms (RCN). Unlike extirpative interventions, intraoperative needle biopsy is the only pathologic data for ablated tumors. It is imperative that sampled tissue accurately captures pathology. We studied the optimal intraoperative needle core biopsy protocol for small RCN during laparoscopic renal cryoablation (LCA). Patients with RCN<4cm underwent intraoperative biopsy during LCA. Four biopsy cores were taken per tumor, 2 before and 2 after LCA by using both a standard and modified technique. Standard technique: needle biopsy device was deployed after insertion into the renal tissue at a depth of 5mm. Modified technique: needle biopsy device was deployed 1mm outside of the renal tissue. Biopsies were examined and compared with reference standard pathology. Percentage agreement was calculated across biopsy types (standard vs. modified) and time points (pre- vs. postcryoablation). Logistic regression was used to identify factors impacting biopsy accuracy. Thirty patients with 33 RCNs underwent LCA. The mean patient age was 69.1±8.0yrs, and mean tumor size was 2.3±0.7cm. No significant bleeding resulted from biopsies. A definitive diagnosis was made in 31/33 RCNs (94.0%). Ten tumors (30.3%) were benign, 21 (63.7%) were malignant, and 2 (6.0%) were nondiagnostic. Biopsy length was significantly longer using the standard vs. modified technique with mean lengths of 9.3mm vs. 7.0mm, respectively (P=.02). Highest agreement was seen in preablation biopsies (90.3%). A significant association with agreement was seen for younger age (P=.05) and larger tumor size (P=.02). Younger age and larger tumor size were associated with improved accuracy. Preoperative sampling resulted in superior accuracy and the standard technique resulted in significantly longer cores. Use of preablation standard biopsy technique may result in the most accurate pathologic diagnosis for patients undergoing cryoablation for small RCNs.JSLS: Journal of the Society of Laparoendoscopic Surgeons / Society of Laparoendoscopic Surgeons 15(4):509-16. · 0.98 Impact Factor -
Article: An evaluation of patient selection criteria on predicting progression-free survival after primary focal unilateral nerve-sparing cryoablation for prostate cancer: recommendations for follow up.
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ABSTRACT: Focal cryoablation targets unilateral disease, sparing healthy tissue and the ipsilateral neurovascular bundle. Given half the prostate is spared, proper patient selection is imperative to optimize outcomes. We report focal cryotherapy outcome data and evaluate the accuracy of the 2007 Task Force patient selection criteria at predicting disease recurrence. This is a retrospective patient chart review from a single academic institution. Inclusion criterion is having unilateral prostate cancer treated with primary hemicryoablation. Patients were stratified using the Task Force selection criteria. Exclusion criterion is having had past radiation or hormone therapy. Progression-free survival was calculated using follow-up TRUS biopsy (biopsy done with transrectal ultrasound) and serial prostate-specific antigen (PSA) results (Phoenix criteria). Kaplan-Meier curves were constructed and Cox regression analyses performed, comparing outcomes across patient selection cohorts. From 2002 to 2009, 77 men underwent primary focal cryosurgery: mean age, 69.5 (SD, 6.7) years; median follow-up time, 24 months (range, 0-87 months); mean precryosurgical PSA, 6.5 (SD, 4.9) ng/mL; median Gleason score, 6 (range, 5-8). There were 44, 31, and 2 men who had D'Amico low-, intermediate-, and high-risk disease, respectively. Seventeen men met Focal Task Force Selection Criteria. After treatment, 22 patients underwent prostate biopsy for suspicion of recurrent disease. Of the 22 patients, 10 (45.5%) had confirmed prostate cancer. Of the 10 patients, 2 had ipsilateral disease, 7 had contralateral disease, and 1 had bilateral disease. Overall biochemical and pathological progression-free survival rates were 72.7% and 87%. The cumulative incidence of biochemical disease progression, using the Kaplan-Meier method, was greater than 75% at 3 years for men with more than 2 positive preoperative biopsy cores and greater than 50% at 5 years for men with 2 or less positive preoperative biopsy cores. No survival differences were seen across cohorts. Pretreatment PSA level, pretreatment Gleason score, number positive cores, and total tumor length were associated with disease progression. Focal cryotherapy is a promising option for carefully selected patients, although optimization of inclusion criteria is required. Current selection criteria are associated with cancer-free survival. Given no accurate definitions for biochemical failure after focal cryotherapy exist combined with our high biochemical failure rate, mandating 12-month follow-up TRUS biopsy may improve accurate detection of cancer progression. Further follow up will determine optimal patient selection criteria and follow-up protocols for patients undergoing primary focal unilateral nerve-sparing prostate cancer treatment.The Cancer Journal 16(5):544-9. · 3.26 Impact Factor
Top co-authors
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Institutions
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2011
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National Health Insurance Corporation Ilsan Hospital
Seoul, Seoul, South Korea
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2010–2011
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Columbia University
- Department of Urology
New York City, NY, USA
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