We determine the ability of percutaneous needle based optical coherence tomography to differentiate renal masses by using the attenuation coefficient (μOCT, mm−1) as a quantitative measure.Materials and Methods:
Percutaneous needle based optical coherence tomography of the kidney was performed in patients presenting with a solid renal mass. A pathology specimen was acquired in the form of biopsies and/or a resection specimen. Optical coherence tomography results of 40 patients were correlated to pathology results of the resected specimens in order to derive μOCT values corresponding with oncocytoma and renal cell carcinoma, and with the 3 main subgroups of renal cell carcinoma. The sensitivity and specificity of optical coherence tomography in differentiating between oncocytoma and renal cell carcinoma were assessed through ROC analysis.Results:
The median μOCT of oncocytoma (3.38 mm−1) was significantly lower (p=0.043) than the median μOCT of renal cell carcinoma (4.37 mm−1). ROC analysis showed a μOCT cutoff value of greater than 3.8 mm−1 to yield a sensitivity, specificity, positive predictive value and negative predictive value of 86%, 75%, 97% and 37%, respectively, to differentiate between oncocytoma and renal cell carcinoma. The area under the ROC curve was 0.81. Median μOCT was significantly lower for oncocytoma vs clear cell renal cell carcinoma (3.38 vs 4.36 mm−1, p=0.049) and for oncocytoma vs papillary renal cell carcinoma (3.38 vs 4.79 mm−1, p=0.027).Conclusions:
We demonstrated that the μOCT is significantly higher in renal cell carcinoma vs oncocytoma, with ROC analysis showing promising results for their differentiation. This demonstrates the potential of percutaneous needle based optical coherence tomography to help in the differentiation of renal masses, thus warranting ongoing research.