Small Animal Surgery Resident The Ohio State University Grandview Heights, Ohio
Optical Coherence Tomography for Surgical Margin Evaluation of Excised Canine Cutaneous and Subcutaneous Tumors. Cheng E1, Selmic LE1, Jennings RN2, Chen CL1, Biggo MR1, Erickson AK1, Dornbusch JA1, Linn SC2, Lapsley J1, Alva BM1, Lorbach JN2, Premanandan C2. 1The Ohio State University, Department of Veterinary Clinical Sciences, Columbus, OH; 2The Ohio State University, Department of Veterinary Biosciences, Columbus, OH.
Current histopathologic methods only sample a small portion of surgical margins and take days for results to finalize. Optical coherence tomography (OCT) allows real-time assessment of tissue morphology of 1–2 mm depth. This study’s aims were: 1) to compare excised canine cutaneous and subcutaneous tumors’ histological and OCT features, and 2) to determine the diagnostic accuracy of OCT for surgical margin evaluation. We hypothesize that OCT imaging would correspond well with histopathology and have high sensitivity for detection of incomplete margins. Eighty dogs were prospectively enrolled. Tumors were excised and imaged with a Thorlabs Telesto OCT system. For Aim 1, areas of interest were marked for comparison of histologic and OCT features. For Aim 2, all surgical margins were recorded systematically. Tumor type and completeness of excision were determined by histopathology. Nine blinded observers received training and then were given a set of Aim 2 images/videos. Observers assigned each image/video a grade from 1 (no cancer) to 4 (cancer) and results were compared to histopathology. The overall median sensitivity and specificity of OCT imaging for detection of incomplete margins were 83.3% and 88.5%, respectively. A potential limitation is that observers had varied experience with OCT image interpretation, ranging from no prior experience to participating in another project over a year ago. OCT has a high sensitivity for detection of incomplete margins and is a promising real-time imaging modality. Further study is needed to evaluate intraoperative applications of OCT and its impact on tumor recurrence and long-term outcome.