Lack of accuracy in preoperative imaging leads to overtreatment of benign renal masses (RMs) or indolent renal cell carcinomas (RCCs). Optical coherence tomography (OCT) is real time and high resolution, enabling quantitative analysis through attenuation coefficient (μOCT, mm(-1)).
To determine the accuracy and diagnostic yield of OCT and renal mass biopsy (RMB) for the differentiation of benign RMs versus RCC and oncocytoma versus RCC.
From October 2013 to June 2016, 95 patients with solid enhancing RMs on cross-sectional imaging were prospectively included. All patients underwent subsequent excision or ablation.
Percutaneous, image-guided, needle-based OCT followed by RMB in an outpatient setting under local anaesthesia.
Accuracy and diagnostic yield, μOCT correlated to resection pathology or second biopsy during ablation. Tables (2×2) for RMB, receiver operating characteristic curve for OCT. Mann-Whitney test to differentiate μOCT of RMs.
RMB diagnostic yield was 79% with sensitivity, specificity, positive predictive value, and negative predictive value (NPV) of 100%, 89%, 99%, and 100%, respectively. Diagnostic yield and added value of OCT to differentiate RCC from benign was 99% and 15%, respectively. Significant difference was observed in median μOCT between benign RMs (3.2mm(-1), interquartile range [IQR]: 2.65-4.35) and RCCs (4.3mm(-1), IQR: 3.70-5.00), p=0.0171, and oncocytomas (3.38mm(-1), IQR: 2.68-3.95) and RCCs (4.3mm(-1), IQR: 3.70-5.00), p=0.0031. OCT showed sensitivity, specificity, positive predictive value. and NPV of 91%, 56%, 91%, and 56%, respectively, to differentiate benign RMs from RCCs and 92%, 67%, 95%, and 55%, respectively, to differentiate oncocytoma from RCC. Limitations include two reference standards and heterogeneity benign RMs.
Compared with RMB, OCT has a higher diagnostic yield. OCT accurately distinguishes benign RMs from RCCs, and oncocytoma from RCCs, although specificity and NPV are lower.
Optical coherence tomography, a new optical scan, exhibits similar sensitivity and positive predictive value than renal mass biopsy, although lower specificity and negative predictive value. Optical coherence tomography has a higher diagnostic yield for diagnosing renal cell carcinoma.
European urology focus. 2017 Oct 24 [Epub ahead of print]
Mara Buijs, Peter G K Wagstaff, Daniel M de Bruin, Patricia J Zondervan, Cemile Dilara Savci-Heijink, Otto M van Delden, Ton G van Leeuwen, R Jeroen A van Moorselaar, Jean J M C H de la Rosette, Maria Pilar Laguna Pes
Department of Urology, AMC University Hospital, Amsterdam, The Netherlands. Electronic address: ., Department of Urology, AMC University Hospital, Amsterdam, The Netherlands., Department of Urology, AMC University Hospital, Amsterdam, The Netherlands; Department of Biomedical Engineering & Physics, AMC University Hospital, Amsterdam, The Netherlands., Department of Pathology, AMC University Hospital, Amsterdam, The Netherlands., Department of Radiology, AMC University Hospital, Amsterdam, The Netherlands., Department of Biomedical Engineering & Physics, AMC University Hospital, Amsterdam, The Netherlands., Department of Urology, VU University Medical Centre, Amsterdam, The Netherlands.