Digistain: a novel biomarker imaging platform for grading breast carcinoma using routinely processed paraffin sections

Objective: Digistain is a new technology platform that enables imaging and quantification of a newly conceived biomarker for grading breast carcinoma in routinely processed, unstained paraffin sections without the use of traditional stains or contrasting agents. By recording a unique optical signature to analyze the chemical make-up of a biopsy quantitatively, the technique is unaffected by the subjectivity of traditional grading. Within minutes of loading a slide it yields a highly reproducible and user independent numerical score reflecting the cellularity of the tumour and its nuclear: cytoplasmic ratio. We report here our findings using an objective technique to grade breast tumours using quantitative criteria. Method: H&E stained sections from excision biopsies of 105 cases of invasive breast carcinoma were reviewed and graded using the ElstonEllis grading system. Unstained sections from each case were loaded into the Digistain platform to yield a numerical score - the Digistain Index (DI). Results: The cases were grouped according to histological grading. Mean DIs was calculated for each grade (1,2 and 3) to be 0.56, 0.61, and 0.68 respectively with a maximum standard error of 0.02. The DI spread within each grade was less than that across the three grades, thus validating this index as a viable grading indicator within the context of this study. Conclusion: We believe the new Digistain approach provides for the first time a cost effective and quantitative measure of tumour grade. This can be developed to deliver an effective assessment of prognosis and recurrence risk beyond traditional qualitative measures based on H&E staining protocols

Room temperature mid-IR single photon spectral imaging

Spectral imaging and detection of mid-infrared (mid-IR) wavelengths are emerging as an enabling technology of great technical and scientific interest; primarily because important chemical compounds display unique and strong mid-IR spectral fingerprints revealing valuable chemical information. While modern Quantum cascade lasers have evolved as ideal coherent mid-IR excitation sources, simple, low noise, room temperature detectors and imaging systems still lag behind. We address this need presenting a novel, field-deployable, upconversion system for sensitive, 2-D, mid-IR spectral imaging. Measured room temperature dark noise is 0.2 photons/spatial element/second, which is a billion times below the dark noise level of cryogenically cooled InSb cameras. Single photon imaging and up to 200 x 100 spatial elements resolution is obtained reaching record high continuous wave quantum efficiency of about 20 % for polarized incoherent light at 3 \mum. The proposed method is relevant for existing and new mid-IR applications like gas analysis and medical diagnostics

Mid-infrared imaging in breast cancer tissue: an objective measure of grading breast cancer biopsies

Introduction : - The majority of cancers are diagnosed using excised biopsy specimens. These are graded, using a g old - standard histopathology protocol based on haemotoxylin and eosin ( “H+E” ) chemical staining . However the grading is done by eye and i f the same biopsy is graded by different practitioners, they typic ally only agree ~70% of the time. The resulting overtreatment problem constitutes a massive unmet need worldwide. Objective: - Our new ‘Digistain ’ technology, uses mid - infrared imaging to map the fractional concentration of nucleic acids, i.e. the n uclea r - to - cytoplasmic chemical ratio (NCR) across an unstained biopsy section. It allows a quantitative “Digistain index” (DI) score, corresponding to the NCR, to be reproducibly extracted from an objective p hysical measurement of a cancer. O ur objective here i s to evaluate its potential for aiding cancer diagnosis for the first time. We correlate the DI scores with H+E grades in a double - blind clinical pilot trial. Methods: - T wo adjacent slices were taken from 75 breast cancer FFPE blocks; one was graded with the standard H+E protocol, and also used to define a “Region of Int erest” (RoI). Digistain was then used to acquire a DI value averaged over the corresponding RoI on the other (unstained) slice and the r esults were statistically analysed. Results : - We find the DI score correlates significantly (p=0.0007) with tumor grade in a way that promises to significantly reduce the inherent subjectivity and variability in biopsy grading. Discussion: The NCR is elevated by increased mitotic activity because cells divide when they are younger and , on average, become smaller as the di sease progresses. Also, extra DNA and RNA is generated as the nuclear transcription machinery goes awry and nuclear pleomorphism occurs . Both effects make the NCR a recognized biomarker for a wide range of tumors, so we expect Digistain will find application in a very wide range of cancers

Spectral Pathology: general discussion.

Parvez Haris opened the discussion of the introductory lecture by Max Diem: Varying degrees of accuracy have been obtained for discrimination between cancerous and non-cancerous tissues using vibrational spectroscopic methods. What are the explanations for these variation in accuracy between cancerous and non-cancerous tissues and how do they correlate with accuracy from other techniques including histopathology

Automated cytological detection of Barrett's neoplasia with infrared spectroscopy.

Development of a nonendoscopic test for Barrett's esophagus would revolutionize population screening and surveillance for patients with Barrett's esophagus. Swallowed cell collection devices have recently been developed to obtain cytology brushings from the esophagus: automated detection of neoplasia in such samples would enable large-scale screening and surveillance