Effectiveness of benzoporphyrin derivative monoacid (BPD-MA) and fiberoptic sensor in detecting metastatic neoplasm in lymph nodes in rats

摘要

Abstract: An intensity ration of the photosensitizing agent to the natural fluorescence was used to determine the condition of lymph nodes (normal, inflammatory, or with metastases). Eighty- one Lobund Wistar rats were inoculated with Pollard rat adenocarcinoma cells. After 40 days the rats were injected with 0.75 mg/kg BPD-MA. A helium-cadmium lasers (442 nm) was used for both light delivery ad fluorescence acquisition. Fluorescence spectra were acquired and analyzed by an optical multichannel analyzer 9 EG&G, OMA III). Unbalanced repeated measures analysis of variance (ANOVA) was done on the mean intensity ratio according to location. Several locations recorded for each rat were modeled as the repeated variable. The fluorescence signal obtained from lymph nodes with metastases indicated high drug amounts, greater than in the skin, tumors, and all other tissues. The lowest fluorescence intensity ratios were observed in the skin. This leads us to the conclusion that the amount of Photofrin porfimer sodium and BPD-MA which localized in the metastatic lymph nodes is higher than in tumor and all other healthy tissues. Among normal lymph nodes there were significant differences according to the site of the node, with the left iliac lymph nodes having higher IR values than either the mesenteric (MC I or MC II) nodes. The geometric means of IR are consistently higher in normal as compared to inflammatory nodes for each location. The optical biopsy needle with laser-induced fluorescence detection and exogenic fluorochrome is a sensitive, novel techniques to localize small boundaries of metastatic neoplasm in lymph nodes. !13