Polarimetric imaging has been comparatively less investigated, at least on real tissues (both ex vivo and in vivo).
There is thus a strong opportunity for scientifically interesting research with potentially high societal impact.
The interpretation of polarimetric images of real tissues is challenging, as tissues are obviously highly complex systems which cannot be “exhaustively” interpreted with a simple optical model.
There is thus room for several approaches, including matrix decompositions as well as Monte Carlo simulations.
We realized such simulations by a state-of the-art code developed by Tatiana Novikova [M.R. Antonelli et al, Opt. Express 10201 (2010)], who supervised Maria Rosaria Antonelli’s thesis, defended in 2011
We thus built the ANR-RNTS “Polarimétrie” project (December 2005 – june 2009) around two essential components:
- A clinical trial, in vivo, of a simple OSC (Orthogonal State Contrast) imager, sufficient to characterize pure depolarizers.
- Full Mueller imaging of surgical samples including tissues other than cervix.
The healthy malpighian epithelium is characterized by a strong retardation (up to 60°) which disappears in both the dysplastic and the glandular tissues.
However, the three types of tissue can be distinguished by decreasing levels of depolarization from healthy malpighian to glandular epithelium.
All these contrasts are almost impossible to visualize in ordinary intensity.
In Sumary that polarimetric imaging has the potential to:
- To distinguish dysplastic from healthy tissues for uterine cervix.
- To identify malignant polyps in colon and provide a first, quick evaluation of the degree of invasion of the tumor, a possibility which would be extremely helpful in colposcopy to optimize the subsequent treatment [A. Pierangelo et al. Opt. Express 19, 1582-1593 (2011)].
- To detect possible residual cancer after radiochemotherapy.
Future Projects and Perspectives
The goal of the PAIRGYNECO project is to boost our activity on uterine cancer management. The project includes three hospital partners:
- Institut Mutualiste Montsouris (IMM)
- Centre Hospitalier Universitaire (CHU) de Bicêtre
- Institut Gustave Roussy (IGR).
The work to be done at the CHU de Bicêtre will be focussed on the detection of dysplasias (on a large number of samples > 200)
The work ar the IGR will be focussed on the detection of residual cancers after radiochemotherapy of locally advanced tumors. This is a crucial issue for the patient survival in good conditions, and no currently available imaging technique is really satisfactory for this purpose.