Detection of squamous neoplasia by fluorescence imaging comparing porfimer sodium fluorescence to tissue autofluorescence in the hamster cheek-pouch model

BACKGROUND: Early neoplastic changes in the oral cavity may be difficult to detect. Fluorescence imaging using porphyrin-derived drugs has been used to enhance detection of neoplasia. Autofluorescence has also been used for this purpose. This paper compares autofluorescence to porfimer sodium-induced fluorescence in the detection of neoplasia in the hamster cheek-pouch model. MATERIALS AND METHODS: Neoplasia was induced in the hamster cheek pouch by the application of 9,10-dimethyl-1,2-benzanthracene. Animals were imaged either with injection of drug (porfimer sodium) or without drug (autofluorescence). Imaging was carried out using a laser-induced fluorescence detection system. Biopies were performed on imaged sections and histologic grades were assigned. RESULTs: Porfimer sodium fluorescence provided 100% sensitivity and specificity in detection of neoplasia. The sensitivity and specificity with autofluorescence was 76% and 83%, respectively. CONCLUSIONS: Autofluorescence provides an accurate means of detecting early neoplastic changes in the hamster cheek-pouch model; however, porfimer sodium imaging does improve detection rates.