In vivo Raman spectroscopy for bladder cancer detection using a superficial Raman probe compared to a nonsuperficial Raman probe

Abstract

Raman spectroscopy is promising as a noninvasive tool for cancer diagnosis. A superficial Raman probe might improve the classification of bladder cancer, because information is gained solely from the diseased tissue and irrelevant information from deeper layers is omitted. We compared Raman measurements of a superficial to a nonsuperficial probe, in bladder cancer diagnosis. Two‐hundred sixteen Raman measurements and biopsies were taken in vivo from at least one suspicious and one unsuspicious bladder location in 104 patients. A Raman classification model was constructed based on histopathology, using a principal‐component fed linear‐discriminant‐analysis and leave‐one‐person‐out cross‐validation. The diagnostic ability measured in area under the receiver operating characteristics curve was 0.95 and 0.80, the sensitivity was 90% and 85% and the specificity was 87% and 88% for the superficial and the nonsuperficial probe, respectively. We found inflammation to be a confounder and additionally we found a gradual transition from benign to low‐grade to high‐grade urothelial carcinoma. Raman spectroscopy provides additional information to histopathology and the diagnostic value using a superficial probe.

Raman Spectroscopic Imaging of Human Bladder Resectates towards Intraoperative Cancer Assessment

“…might point to a factor in the development of malignancies and might have been overlooked so far by state-of-the art modalities such as histopathology, immunohistochemistry and fluorescence that usually administer stains to enhance contrast. Advantages of Raman spectroscopy include that (i) no stains are required, (ii) unprocessed tissue can be analyzed, (iii) algorithms can be applied without complex data pre-processing such as VCA in this and earlier work [ 13 , 16 , 21 ], and (iv) even in vivo applications are possible using fiber optic probes [ 6 , 7 , 8 , 10 , 11 , 29 ].…”

“…Raman spectroscopy provided a slightly better sensitivity, but lower specificity for the grading of low- and high-grade tissues than optical coherence tomography [ 10 ]. A superficial Raman probe was compared to a non-superficial Raman probe for the in vivo Raman spectroscopy of bladder cancer [ 11 ]. Overall, 216 Raman measurements and biopsies were taken in vivo from at least one suspicious and one unsuspicious bladder location in 104 patients.…”

Current Trends of Raman Spectroscopy in Clinic Settings: Opportunities and Challenges

“…Lin et al [84] combined white-light imaging with a four-mode endoscopic system developed using diffuse reflection, spontaneous fluorescence imaging, and Raman spectroscopy, which can be used for in vivo imaging in clinical practice, as illustrated in Figure 8d. Cordero et al [85] introduced a Raman imaging system based on a compact fiber probe to characterize in vitro tumor grading. They created the first in vivo endoscopic cancer detection system that combined white light imaging (WLI), autofluorescence imaging (AFI), diffuse reflectance spectroscopy, and Raman spectroscopy.…”

“…Cordero et al. [ 85 ] introduced a Raman imaging system based on a compact fiber probe to characterize in vitro tumor grading. They created the first in vivo endoscopic cancer detection system that combined white light imaging (WLI), autofluorescence imaging (AFI), diffuse reflectance spectroscopy, and Raman spectroscopy.…”

Image-guided Raman spectroscopy navigation system to improve transperineal prostate cancer detection. Part 2: in-vivo tumor-targeting using a classification model combining spectral and MRI-radiomics features

“… 18 , 21 – 24 Based on inelastic light scattering, RS has been used for years for ex-vivo sample characterization, producing spectra with molecular vibrational states information, showing great potential for detecting several diseases. 25 – 28 Furthermore, with the development of optical fiber RS probes, this technique is moving to clinical applications 29 ; different optical probe designs have been used for in-vivo tissue characterization (in human and animal models) for targeting skin cancer in open surgeries, 30 minimally invasive diagnosis of lung cancers, 31 bladder cancer detection using a superficial and nonsuperficial Raman probes, 32 observation of skin changes after breast cancer treatment, 33 and others. 34 – 37 In prostate applications, it has been used for ex-vivo characterization and in-vivo margin detection, 19 , 20 , 23 , 38 , 39 but, to the best of our knowledge, so far, not for real-time in-vivo prostate tumor burden confirmation, which can provide great benefit for clinical procedures.…”