Evaluation to Differentiate between Tumor Lesions and the Parenchyma in Partial Nephrectomies for Renal Tumors Based on Quantitative Fluorescence Imaging Using Indocyanine Green Dye

INTRODUCTION: Near-infrared fluorescence imaging with indocyanine green is a useful tool during partial nephrectomy. Because an accurate method for judging hasn't been established yet, the success rate may be slightly different and inconsistent. MATERIALS AND METHODS: A total of 21 cases with suspected renal cancers who had undergone a partial nephrectomy were enrolled. We examined differences in the success rate between malignant lesions and the parenchyma by quantifying fluorescence in the pre-resection and ex vivo phases. RESULTS: Pre-resection imaging showed a significant degradation of fluorescence in the focused lesion in 76.2% (16/21) of cases. A significant degradation was observed in 73.7% (14/19) of the total malignant lesions, 70.5% (12/17) of cases with a clear cell lesion, 100% (2/2) of cases with non-clear cell lesions, and 100% (2/2) of benign angiomyolipomas. In contrast, imaging of the ex vivo resected specimens showed a significant degradation in fluorescence of the focused lesions in 85.7% (18/21) of cases. A significantly degradation was observed in 84.2% (16/19) of the total malignant lesions, 82.3% (14/17) of cases with a clear cell lesion, 100% (2/2) of cases with non-clear cell lesions, and 100% (2/2) of benign angiomyolipomas. CONCLUSION: We firstly evaluated the efficacy of quantitative indocyanine green-based fluorescence as an objective method.