Department of Radiation Oncology, School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, PA 19104, USA.
Phys Med Biol. 2013 May 21;58(10):3461-80. doi: 10.1088/0031-9155/58/10/3461. Epub 2013 Apr 30.
Interstitial diffuse optical tomography (DOT) has been used to characterize spatial distribution of optical properties for prostate photodynamic therapy (PDT) dosimetry. We have developed an interstitial DOT method using cylindrical diffuse fibers (CDFs) as light sources, so that the same light sources can be used for both DOT measurement and PDT treatment. In this novel interstitial CDF-DOT method, absolute light fluence per source strength (in unit of 1 cm(-2)) is used to separate absorption and scattering coefficients. A mathematical phantom and a solid prostate phantom including anomalies with known optical properties were used, respectively, to test the feasibility of reconstructing optical properties using interstitial CDF-DOT. Three dimension spatial distributions of the optical properties were reconstructed for both scenarios. Our studies show that absorption coefficient can be reliably extrapolated while there are some cross talks between absorption and scattering properties. Even with the suboptimal reduced scattering coefficients, the reconstructed light fluence rate agreed with the measured values to within ±10%, thus the proposed CDF-DOT allows greatly improved light dosimetry calculation for interstitial PDT.
间质漫射光学层析成像（DOT）已被用于描述前列腺光动力疗法（PDT）剂量学中光学特性的空间分布。我们已经开发了一种使用圆柱形漫射光纤（CDF）作为光源的间质 DOT 方法，这样相同的光源可以同时用于 DOT 测量和 PDT 治疗。在这种新型的间质 CDF-DOT 方法中，使用单位为 1 cm(-2) 的每个光源的绝对光通量来分离吸收和散射系数。使用数学体模和包含已知光学特性的实体前列腺体模分别测试了使用间质 CDF-DOT 重建光学特性的可行性。针对这两种情况，重建了光学特性的三维空间分布。我们的研究表明，即使在吸收和散射特性之间存在一些交叉影响，吸收系数也可以可靠地外推。即使在散射系数不太理想的情况下，重建的光通量率与测量值之间的误差也在±10%以内，因此所提出的 CDF-DOT 允许对间质 PDT 的光剂量计算进行极大的改进。
