title: Multispectral Mueller polarimetric imaging detecting residual cancer and cancer regression after neoadjuvant treatment for colorectal carcinomas.
abstract: This work is devoted to a first exploration of Mueller polarimetric imaging for the detection of residual cancer after neoadjuvant treatment for the rectum. Three samples of colorectal carcinomas treated by radiochemotherapy together with one untreated sample are analyzed ex vivo before fixation in formalin by using a multispectral Mueller polarimetric imaging system operated from 500 to 700 nm. The Mueller images, analyzed using the Lu-Chipmann decomposition, show negligible diattenuation and retardation. The nonirradiated rectum exhibits a variation of depolarization with cancer evolution stage. At all wavelengths on irradiated samples, the contrast between the footprint of the initial tumor and surrounding healthy tissue is found to be much smaller for complete tumor regression than when a residual tumor is present, even at volume fractions of the order of 5%. This high sensitivity is attributed to the modification of stromal collagen induced by the cancer. The depolarization contrast between treated cancer and healthy tissue is found to increase monotonously with the volume fraction of residual cancer in the red part of the spectrum. Polarimetric imaging is a promising technique for detecting short-time small residual cancers, which is valuable information for pathological diagnosis and patient management by clinicians.
authors.affiliation: Laboratoire de Physique des Interfaces et Couches Minces, Ecole Polytechnique, Centre National de Recherche Scientifique, Palaiseau 91128, France. angelo.pierangelo@poly.polytechnique.fr
authors.forename: Angelo
authors.initials: A
authors.lastname: Pierangelo
authors.forename: Sandeep
authors.initials: S
authors.lastname: Manhas
authors.forename: Abdelali
authors.initials: A
authors.lastname: Benali
authors.forename: Clément
authors.initials: C
authors.lastname: Fallet
authors.forename: Jean-Laurent
authors.initials: JL
authors.lastname: Totobenazara
authors.forename: Maria-Rosaria
authors.initials: MR
authors.lastname: Antonelli
authors.forename: Tatiana
authors.initials: T
authors.lastname: Novikova
authors.forename: Brice
authors.initials: B
authors.lastname: Gayet
authors.forename: Antonello
authors.initials: A
authors.lastname: De Martino
authors.forename: Pierre
authors.initials: P
authors.lastname: Validire
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry / Q000175:diagnosis / Q000473:pathology / Q000628:therapy*; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy*; D003952:Diagnostic Imaging / Q000295:instrumentation / Q000379:methods*; D006651:Histocytochemistry / Q000379:methods; D006801:Humans; D020360:Neoadjuvant Therapy; D018365:Neoplasm, Residual / Q000737:chemistry / Q000175:diagnosis* / Q000473:pathology; D016896:Treatment Outcome