Needle-based optical coherence tomography for the detection of prostate cancer: a visual and quantitative analysis in 20 patients

Abstract

Diagnostic accuracy of needle-based optical coherence tomography (OCT) for prostate cancer detection by visual and quantitative analysis is defined. 106 three-dimensional (3-D)-OCT data sets were acquired in 20 prostates after radical prostatectomy and precisely matched with pathology. OCT images were grouped per histological category. Two reviewers performed blind assessments of the OCT images. Sensitivity and specificity for malignancy detection were calculated. Quantitative analyses by automated optical attenuation coefficient calculation were performed. OCT can reliably differentiate between fat, cystic, and regular atrophy and benign glands. The overall sensitivity and specificity for malignancy detection was 79% and 88% for reviewer 1 and 88% and 81% for reviewer 2. Quantitative analysis for differentiation between stroma and malignancy showed a significant difference (4.6 mm - 1 versus 5.0 mm - 1 Mann-Whitney U-test p < 0.0001). A Kruskal-Wallis test showed a significant difference in median attenuation coefficient between stroma, inflammation, Gleason 3, and Gleason 4 (4.6, 4.1, 5.9, and 5.0 mm - 1, respectively). However, attenuation coefficient varied per patient and a related-samples Wilcoxon signed-rank test showed no significant difference per patient (p = 0.17). This study confirmed the one to one correlation of histopathology and OCT. Precise matching showed that most histological tissues categories in the prostate could be distinguished by their unique pattern in OCT images. In addition, the optical attenuation coefficient can play a role in the differentiation between stroma and malignancy; however, a per patient analysis of the optical attenuation coefficient did not show a significant difference.

The First In Vivo Needle‐Based Optical Coherence Tomography in Human Prostate: A Safety and Feasibility Study

“…Different from our previous ex-vivo studies, [12,23,24] the light seems to penetrate deeper in vivo for stroma compared with the Gleason patterns. This difference in penetration depth should be exploited in future studies by determining the optical attenuation coefficient.…”

“…Second column is modified from Muller et al The numbers identify with the arrows in Figure at different visual OCT features.…”

“…). The visual difference between Gleason 3 and 4 is small, which makes it difficult to differentiate these tissues on OCT . By comparing OCT pullback #4 with the corresponding histology slide, we were able to identify the benign glands and stroma but could not determine the regular atrophy.…”

“…The in vivo images contain comparable features as the ex vivo OCT images from the previous study. [12] Differences of in vivo and ex vivo images were found in the regular atrophy where the lumens appeared to be smaller. Benign glands showed its characteristic cavities with a few thin shadows.…”

“…This difference in penetration depth should be exploited in future studies by determining the optical attenuation coefficient. [12,23,24] The possibility of collecting good quality images of the prostate with needle-based OCT measurements is now the first successful step towards a larger cohort study that aims to correlate OCT with histology to set up in vivo discriminative parameters. [13] By using two highly selected patients with PCa prior to this proposed correlation study, we follow the IDEAL recommendations [25].…”