title: Elastic scattering spectroscopy for intraoperative determination of sentinel lymph node status in the breast.
abstract: The ability to provide the best treatment for breast cancer depends on establishing whether or not the cancer has spread to the lymph nodes under the arm. Conventional assessment requires tissue removal, preparation, and expert microscopic interpretation. In this study, elastic scattering spectroscopy (ESS) is used to interrogate excised nodes with pulsed broadband illumination and collection of the backscattered light. Multiple spectra are taken from 139 excised nodes (53 containing cancer) in 68 patients, and spectral analysis is performed using a combination of principal component analysis and linear discriminant analysis to correlate the spectra with conventional histology. The data are divided into training and test sets. In test sets containing spectra from only normal nodes and nodes with complete replacement by cancer, ESS detects the spectra from cancerous nodes with 84% sensitivity and 91% specificity (per-spectrum analysis). In test sets that included normal nodes and nodes with partial as well as complete replacement by cancer, ESS detects the nodes with cancer with an average sensitivity of 75% and specificity of 89% (per-node analysis). These results are comparable to those from conventional touch imprint cytology and frozen section histology, but do not require an expert pathologist for interpretation. With automation of the technique, results could be made available almost instantaneously. ESS is a promising technique for the rapid, accurate, and straightforward detection of metastases in excised sentinel lymph nodes.
authors.affiliation: National Medical Laser Centre, University College London, Royal Free and University College Medical School, Academic Division of Surgical Specialities, and Department of Surgery, London, United Kingdom.
authors.forename: Kristie S
authors.initials: KS
authors.lastname: Johnson
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Chicken
authors.forename: David C O
authors.initials: DC
authors.lastname: Pickard
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Lee
authors.forename: Gavin
authors.initials: G
authors.lastname: Briggs
authors.forename: Mary
authors.initials: M
authors.lastname: Falzon
authors.forename: Irving J
authors.initials: IJ
authors.lastname: Bigio
authors.forename: Mohammed R
authors.initials: MR
authors.lastname: Keshtgar
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Bown
mesh_terms: D000465:Algorithms; D001365:Axilla; D001943:Breast Neoplasms / Q000737:chemistry / Q000145:classification / Q000175:diagnosis / Q000473:pathology*; D016002:Discriminant Analysis; D004548:Elasticity; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007430:Intraoperative Care / Q000379:methods; D008027:Light; D008198:Lymph Nodes / Q000737:chemistry / Q000473:pathology*; D008207:Lymphatic Metastasis; D025341:Principal Component Analysis; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D013057:Spectrum Analysis / Q000379:methods*; D041622:Tomography, Optical / Q000379:methods*