Optimal fluorescence excitation wavelengths for detection of squamous intra-epithelial neoplasia: results from an animal model

Abstract

Using the hamster cheek pouch carcinogenesis model, we explore which fluorescence excitation wavelengths are useful for the detection of neoplasia. 42 hamsters were treated with DMBA to induce carcinogenesis, and 20 control animals were treated only with mineral oil. Fluorescence excitation emission matrices were measured from the cheek pouches of the hamsters weekly. Results showed increased fluorescence near 350-370 nm and 410 nm excitation and decreased fluorescence near 450-470 nm excitation with neoplasia. The optimal diagnostic excitation wavelengths identified using this model - 350-370 nm excitation and 400-450 nm excitation - are similar to those identified for detection of human oral cavity neoplasia.

Investigation of fiber‐optic probe designs for optical spectroscopic diagnosis of epithelial pre‐cancers

“…A subset of these excitation wavelengths are consistent with those identified in a previous study in which multi-excitation fluorescence spectroscopy (between 330-500 nm excitation) of the DMBA-treated hamster cheek pouch was carried out using a similar probe geometry (22). Coghlan et al (22) found that fluorescence spectra at excitation wavelengths between 350-370 nm and 400-450 nm provide the greatest discrimination between dysplastic and normal tissues.…”

“…The treatment schedule of 8-16 weeks was established from the results of previous studies to yield a majority of tissues with mild to severe dysplasia (18)(19)(20)(21)(22)(23)(24)(25).…”

Comparative evaluation of differential laser-induced perturbation spectroscopy as a technique to discriminate emerging skin pathology

“…26,27,41 While our study found improved performance using the DLIPS technique, other studies have reported accuracy rates up to 90% for detecting precancerous morphological changes and sensitivities and specificities ranges of 76 to 95% and 83 to 95%, respectively, when using fluorescence spectroscopy. 26,41,44,45 However, a major difference of these studies was the focus on an algorithmic approach to boosting detection performance using techniques like partial least squares discriminant analysis or a support vector machine to develop a maximized basis on which to separate the data and subsequently only resolve a single detection operating point. 27,41,46 In diagnostic medicine, there is often a much greater cost associated with a false negative result as opposed to a false positive, as evidenced by the high sensitivities and low specificities reported for physician-driven diagnostic techniques.…”

“…Tumor formation on female athymic nude mice (Hsd: Athymic Nude-Foxn1 nu , Harlan Laboratories, Indianapolis IN), six to eight weeks old, was induced and promoted by 7,12-dimethylbenz(a)anthracene (DMBA) (Sigma-Aldrich, St. Louis, MO) in mineral oil (Fisher Scientific, Pittsburgh, PA) at a concentration of 0.5% w∕w applied topically to the dorsal skin according to previously described methods. [25][26][27][28][29][30][31] Application was repeated two to three times per week throughout the 11 week course of the experiment. DMBA application was discontinued if mice began exhibiting signs of systemic toxicity, particularly weight loss.…”

A theoretical‐experimental methodology for assessing the sensitivity of biomedical spectral imaging platforms, assays, and analysis methods

“…A range of analysis approaches have also been demonstrated for biomedical spectral imaging applications, including unmixing [8,[57][58][59], PCA and similar approaches [58,[60][61][62], and others [29,63,64]. However, only a limited amount of research has been performed to apply many of the spectral image processing algorithms developed by the remote sensing community to biomedical applications [10].…”