Photodiagnosis and Photodynamic Therapy (2013) 10, 168—172 Available online at www.sciencedirect.com jo ur nal ho mepage: www.elsevier.com/locate/pdpdt A parallelism between spectral grading and Gleason grading of malignant prostate tissues V. Masilamani a , M.S. AlSalhi a , S. Devanesan a , M. Atif PhD, MPhil a,d,* , D. Rabah b , K. Farhat b , Y. Pu c , R.R. Alfano c a Research Chair on Laser Diagnosis of Cancers, King Saud University, Riyadh, Saudi Arabia b Princess Johara Al-Ibrahim Center for Cancer Research, Surgery, College of Medicine, King Saud University, Riyadh, Saudi Arabia c IUSL, CCNY, The City University of New York, New York, NY 10031, United States d National Institute of Lasers and Optronics, Islamabad, Pakistan Available online 15 January 2013 KEYWORDS Spectral grading and Gleason grading; Malignant prostate tissue; Stokes’ shift spectra Summary Gleason score is the most common method of grading the virulence of prostate malignancy and is based on the pathological assessment of morphology of cellular matrix. Since this involves the excision of the tissue, we are working on a new, minimally invasive, non- contact, procedure of spectral diagnosis of prostate malignancy. In this preliminary in vitro study reported here, we have analyzed 27 tissue samples (normal control = 7: benign = 8: malig- nant = 12) by Stokes’ shift spectra (SSS) to establish a one-to-one correspondence between spectral grading and Gleason grading. © 2012 Elsevier B.V. All rights reserved. Introduction Gleason score (GS) is the most common method of grading the prostate cancer tissue in order to understand how much and how fast the malignancy is spreading. This kind of sco- ring, though subjective and varies considerably between two professional pathologists, has been a useful tool for long- term prognosis of the afflicted patients. This score is based on the microscopic appearance of the tissue and the greater the score the more aggressive the disease and the worse the prognosis. ∗ Corresponding author. E-mail addresses: atifhull@gmail.com, atif ramzan@hotmail.com (M. Atif). The pathologist assigns a score 1 for the normal well differentiated tissue which has small, well formed uniform glands; he assigns a score of 5 for the poorly differentiated, irregular mesh of cells with few glands. Most often the tis- sues do not have such well defined structure, but exhibit a mix of two patterns: A primary or the most prominent pattern and a secondary, less prominent pattern, say 3 and 4 or 4 and 3. Though for both cases the total score is 7, the former one has better prognosis than the latter. The primary pattern determines the Gleason grade, which runs from 1 to 5; the combination of grades of two important patterns is called Gleason score [1]. The objective of this article is to establish a parallelism between the Gleason score of microscopic cellular morphology and the spectral features of fluorescent biomarkers of the malignant prostate tissues. 1572-1000/$ — see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.pdpdt.2012.12.002