Chen Q, Wilson B C, Dereski M O, Patterson M S, Chopp M, Hetzel F W
Department of Radiation Oncology, Henry Ford Hospital, Detroit, MI 48202.
Photochem Photobiol. 1992 Sep;56(3):379-84. doi: 10.1111/j.1751-1097.1992.tb02174.x.
The light fluence distributions of 632.8 nm light incident on the exposed surface of normal rat brain in vivo have been measured using an interstitial, stereotactically-mounted optical fiber detector with isotropic response. The dependence of the relative fluence rate on depth and the spatial distribution of fluence were compared for incident beam diameters of 3 and 5 mm. The fluence rate at depth of 1-6 mm along the optical axis within the brain tissue was approximately 70% greater for a 5 mm diameter beam than for a 3 mm beam, at the same incident fluence rate, although the plots of the relative fluence rate vs depth were parallel over the depth range 1-6 mm. The depths of necrosis resulting from photodynamic treatment of brain tissue using the photosensitizer Photofrin and irradiation by 632 nm light with 3 and 5 mm incident beams were also measured. The observed difference in necrosis depths was consistent with the measured difference in fluence. The importance of beam size in photodynamic treatment with small diameter incident light fields is discussed.
使用具有各向同性响应的间质立体定向安装光纤探测器，测量了632.8 nm光入射到正常大鼠活体脑暴露表面时的光通量分布。比较了3 mm和5 mm入射光束直径下相对光通量率对深度的依赖性以及光通量的空间分布。在相同的入射光通量率下，对于5 mm直径的光束，沿光轴在脑组织内1 - 6 mm深度处的光通量率比3 mm光束大约高70%，尽管相对光通量率与深度的曲线在1 - 6 mm深度范围内是平行的。还测量了使用光敏剂Photofrin并用3 mm和5 mm入射光束的632 nm光对脑组织进行光动力治疗所导致的坏死深度。观察到的坏死深度差异与测量的光通量差异一致。讨论了小直径入射光场在光动力治疗中光束大小的重要性。
