Indocyanine Green Cannot Predict Malignancy in Partial Nephrectomy: Histopathologic Correlation with Fluorescence Pattern in 100 Patients
ABSTRACT INTRODUCTION: Indocyanine Green (ICG) is emerging as a potential adjunct to robotic partial nephrectomy by its ability to aide in the real-time identification of renal vasculature, renal masses, and the renal mass-parenchymal margin. The fluorescence patterns of renal masses have not been adequately described according to histology and it remains unknown if fluorescence pattern can reliably predict histology or malignancy. We therefore describe the ICG fluorescence pattern of our first 100 robotic partial nephrectomies and correlate with histology. METHODS: We reviewed our prospective robotic partial nephrectomy database and categorized fluoresce pattern as isofluoresent (same as surrounding parenchyma), hypofluorescent (less than surrounding parenchyma, but with uptake), or afluorescent (no visable uptake of dye). Descriptive statistics were applied. RESULTS: All 14 cystic lesions were afluorescent, and comprised 9 malignant and 5 benign masses. Eighty-six lesions were solid, of which 3 were isofluorescent including two clear cell and one translocation tumor. The remaining 83 solid lesions were hypoflurescent and included 65 malignant and 18 benign lesions. Clear cell was the most common histology of which 96% were hypofluorescent and 4% isofluorescent. In determining malignant vs. benign lesions, hypofluorescence had a positive predictive value of 87%, negative predictive value of 52%, sensitivity of 84% and specificity of 57%. CONCLUSIONS: A three grade classification of renal mass ICG fluorescence pattern is correlated with some histologic findings, but unable to reliably predict malignant versus benign lesions.
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ABSTRACT: PURPOSE: Near-infrared fluorescence (NIRF) allows differentiation of tumors and normal parenchyma during robotic partial nephrectomy (RPN). This may facilitate tumor excision but requires proper dosing of indocyanine green (ICG). Underdosing causes inadequate fluorescence of peri-tumor parenchyma. Overdosing causes tumors to inappropriately fluoresce. Currently, there are no described dosing strategies to optimize NIRF, with reported doses varying widely. We devised a dosing strategy and assessed reliability of NIRF for differential fluorescence. MATERIALS/METHODS: RPN with NIRF was performed for 79 tumors. Dosing strategy involved at minimum two ICG doses, including test dose and calibrated dose prior to resection. The test dose was deliberately low to avoid confounding over-fluorescence. The second dose was calibrated depending on extent of differential fluorescence achieved with test doses. Intraoperative assessment of tumor fluorescence was recorded before pathology. RESULTS: Mean tumor size was 3.5cm (1.1-9.8) with mean RENAL score of 8 (4-12). The median ICG test dose and re-dose prior to clamping were 1.25mg (0.625-2.5) and 1.875 mg (0.625-5). Differential fluorescence was achieved in 65/79 tumors (82%) that did not fluoresce. After 3 exclusions for inability to assess fluorescence or indeterminate histology, 60/76 were renal cell carcinoma (RCC). Fifty-five of 60 RCCs behaved appropriately and did not fluoresce (92%). Overall, 65/76 tumors behaved appropriately for an 86% agreement between histology and NIRF behavior. CONCLUSION(S): With our dosing regimen, NIRF was highly reliable in achieving differential fluorescence of kidney and RCCs. Standardized dosing is needed before deciding whether NIRF improves RPN outcomes, and additional studies may further improve reliability.The Journal of urology 04/2013; 190(5). DOI:10.1016/j.juro.2013.04.072 · 3.75 Impact Factor
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ABSTRACT: Near-infrared fluorescence (NIRF) imaging is a technology with emerging applications in urologic surgery. To describe surgical techniques and provide clinical outcomes for robotic partial nephrectomy (RPN) with selective clamping and robotic upper urinary tract reconstruction featuring novel applications of NIRF imaging. Data from 90 patients who underwent successful RPN with selective clamping or upper urinary tract reconstruction utilizing NIRF imaging between April 2011 and October 2012 were reviewed. We performed RPN utilizing NIRF imaging to aid with selective clamping and upper tract reconstruction with NIRF imaging, the details of which are outlined in this paper and the accompanying video. Patient characteristics, perioperative outcomes, and complications were analyzed. Of the 48 RPN patients for whom selective clamping was attempted successfully, median estimated blood loss was 200.0ml, warm ischemia time was 17.0min, and median change in estimated glomerular filtration rate was -6.3%. There was a 12.5% complication rate, and all complications were Clavien grade 1-3 (14.3%). The upper urinary tract reconstruction utilizing NIRF imaging was performed in 42 patients and included pyelopasty (n=20), ureteral reimplant (n=13), ureterolysis (n=7), and ureteroureterostomy (n=2). Radiographic and symptomatic improvement was observed in 100% of the pyeloplasty, ureteral reimplant, and ureteroureterostomy patients and 71.4% of ureterolysis patients, for an overall success rate of 95.2%. This study is limited by the small sample size, the short follow-up period, and the lack of a comparative cohort. Our technique of RPN with selective arterial clamping and robotic upper urinary tract reconstruction utilizing NIRF imaging is presented. This technology provides real-time intraoperative angiogram to confirm selective ischemia and may be an adjunct technology to confirm well-perfused tissue within a reconstruction anastomosis. Further investigation is needed to evaluate long-term outcomes of NIRF imaging in robotic upper urinary tract surgery and to delineate its indications.European Urology 09/2013; 65(4). DOI:10.1016/j.eururo.2013.09.023 · 12.48 Impact Factor
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ABSTRACT: To review optical imaging technologies in urologic surgery aimed to facilitate intraoperative imaging and tissue interrogation. Emerging new optical imaging technologies can be integrated in the operating room environment during minimally invasive and open surgery. These technologies include macroscopic fluorescence imaging that provides contrast enhancement between normal and diseased tissue and microscopic imaging that provides tissue characterization. Optical imaging technologies that have reached the clinical arena in urologic surgery were reviewed, including photodynamic diagnosis, near infrared fluorescence imaging, optical coherence tomography, and confocal laser endomicroscopy.Current opinion in urology 11/2013; DOI:10.1097/MOU.0000000000000010 · 2.12 Impact Factor