Optical spectroscopy techniques can accurately distinguish benign and malignant renal tumours

Abstract

What's known on the subject? and What does the study add?• There is little known about optical spectroscopy techniques ability to evaluate renal tumours.• This study shows for the first time the ability of Raman and optical reflectance spectroscopy to distinguish benign and malignant renal tumours in an ex vivo environment. We plan to develop this optical assistance in the operating room in the near future. Objective• To evaluate the ability of Raman spectroscopy (RS) and optical reflectance spectroscopy (ORS) to distinguish benign and malignant renal tumours at surgery. Materials and Methods• Between March and October 2011, RS and ORS spectra were prospectively acquired on surgical renal specimens removed for suspicion of renal cell carcinoma (RCC). Optical measurements were done immediately after surgery.• Optical signals were normalised to ensure comparison between spectra. Initial and final portions of each spectrum were removed to avoid artefacts. • A support vector machine (SVM) was built and tested using a leave-one-out cross-validation.• Classification scores, including accuracy, sensitivity and specificity were calculated on the entire population and in patients with tumours of <4 cm. Results• In all, 60 nephrectomies were performed for 53 malignant tumours (41 clear-cell, eight papillary and four chromophobe carcinomas) and seven benign tumours (four oncocytomas, two angiomyolipomas and a haemorrhagic cyst). In all, >700 optical spectra were obtained and submitted to SVM classification.• The SVM could recognise benign and malignant renal tumours with an accuracy of 96% (RS) and 88% (ORS) in the whole population and with an accuracy of 93% (RS) and 95% (ORS) in the present subset of small renal tumours (<4 cm).• Histological subtype could be determined in 80% and 88% of the cases with RS and ORS, respectively. • The SVM was able to differentiate chromophobe carcinomas and benign lesions with an accuracy of 96% in RS and 98% in ORS. Conclusion• Benign and malignant renal tumours can be accurately discriminated by a combination of RS and ORS. In vivo experiments are needed to further assess the value of optical spectroscopy techniques.

Label-free molecular imaging of the kidney

“…They reported that RA-MS was able to discriminate with high accuracy (specificity and sensitivity of >80%) between (i) normal and tumor tissues, (ii) benign and malign tumors, (iii) low-grade and high-grade tumors, and 4) clear cell carcinoma, papillary tumors, and chromophobe tumors. Couapel et al 177 confirmed these results by distinguishing between benign and malignant renal tumors using RA-MS in combination with supervised multivariate processing.…”

Renal mass biopsy using Raman spectroscopy identifies malignant and benign renal tumors: potential for pre-operative diagnosis

“…Compared to previous studies [9, 10], we first provided characteristic Raman spectrum for each type of renal tumor. These spectra could potentially serve as chemical “fingerprints” and be used for pre-operative diagnosis.…”

“…And it needs no sample pre-treatment or external labeling, and requires only a few seconds. Previous publications have presented the use of RS to detect the whole mass of renal tumor [9, 10], but no study on Raman's investigation of biopsy specimen was ever reported. In this context, we mimicked pre-operative RMB by collecting biopsy specimen from surgical removed kidney to determine whether RS is able to distinguish malignant and benign renal tumors, and serve as a complementary diagnostic tool in the future.…”

Light Reflectance Spectroscopy and Autofluorescence (Kidney and Prostate)

“…Accuracy for distinguishing between histological subtypes was 88-90 % overall and 89-95 % for small renal masses. Accuracy for distinguishing between chromophobe RCC and benign histology was 98-100 % [ 15 ]. To date, these fi ndings have not been investigated in vivo and technology that would enable this is pending.…”

“…Recently, Couapel et al investigated the ability of light refl ectance spectroscopy and Raman spectroscopy to differentiate benign from malignant renal tissue as well as to differentiate between histological subtypes of RCC [ 15 ]. Spectra were collected prospectively in a cohort of 60 patients who underwent radical or partial nephrectomy for suspicion of cancer.…”