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Localization of experimental submucosal esophageal tumor in rabbits by using mono‐L‐aspartyl chlorin e6 and long‐wavelength photodynamic excitation
Author(s) -
Sheyhedin Ilyar,
Okunaka Tetsuya,
Kato Harubumi,
Yamamoto Yutaka,
Sakaniwa Nobuyuki,
Konaka Chimori,
Aizawa Katsuo
Publication year - 2000
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/(sici)1096-9101(2000)26:1<83::aid-lsm12>3.0.co;2-1
Subject(s) - fluorescence , laser , photodynamic therapy , excitation wavelength , chemistry , chlorin , intensity (physics) , pathology , nuclear medicine , materials science , optics , medicine , physics , organic chemistry
Background and Objective To increase the applicability of photodynamic diagnosis with regard to deep‐seated tumor, we illuminated tumors with a long‐wavelength laser beam after photosensitization with mono‐L‐aspartyl chlorin e6 (NPe6). Study Design/Materials and Methods Rabbits with VX2 esophageal tumors were divided into four groups. The control group was not treated, and the other three groups were injected with 1, 2.5, and 5 mg/kg mono‐L‐aspartyl chlorin e6 (NPe6), respectively. After excitation with a 664‐nm laser beam (10 mW, 10 seconds), the fluorescence image and the relative fluorescence intensity (tumor/normal tissue) were recorded every 2 hours up to 8 hours by a newly developed diode laser endoscopic fluorescence imaging system. The tissue concentration of NPe6 was examined by high performance liquid chromatography at 2, 4, and 6 hours after injection with 1 and 5 mg/kg NPe6. Results The diode laser endoscopic fluorescence imaging system was able to selectively detect fluorescence from submucosal tumor by comparison with the surrounding normal mucosa after NPe6 injection. The fluorescence intensity correlated with NPe6 dose, selectively accumulated in the tumor tissue and relative intensity peaked at 6 hours after injection. No fluorescent images were detected in controls. Conclusion Given intravenously, NPe6 at a dose of 5 mg/kg and excited with a 664‐nm wavelength laser beam 6 hours later can define experimentally induced deep‐seated esophageal carcinoma in rabbits, by using an endoscopic fluorescence imaging system. Lasers Surg. Med. 26:83–89, 2000. © 2000 Wiley‐Liss, Inc.