ANALYSIS OF TISSUE OPTICAL COEFFICIENTS USING AN APPROXIMATE EQUATION VALID FOR COMPARABLE ABSORPTION AND SCATTERING
ANALYSIS OF TISSUE OPTICAL COEFFICIENTS USING AN APPROXIMATE EQUATION VALID FOR COMPARABLE ABSORPTION AND SCATTERING
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DOI：
10.1088/0031-9155/37/6/002
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发表时间：
1992-06-01
影响因子：
3.5
通讯作者：
MCPHEE, MS
中科院分区：
文献类型：
--
作者：
ARNFIELD, MR;MATHEW, RP;MCPHEE, MS
与Photofrin II一起使用的由波长超过630 nm的光激活的新型光敏剂正在接受多个组织的癌症治疗评估。与Photofrin II相比，这些试剂破坏的肿瘤体积的任何增加都将部分取决于较长波长下的组织透过率。测量了不同组织在630 nm和更具穿透性的近红外波长789 nm处的衰减系数。通过与传输方程的严格解的比较，证明了一个新的光在组织中传播的模型对于任意的吸收和散射比是精确的。通过将该模型与光衰减测量进行拟合，得到了组织在630 nm和789 nm处的吸收和传输散射系数。体外组织包括牛的心脏、肾脏和舌头、猪的肝脏和脂肪、鸡肉；体内组织包括Dunning R3327-AT和R3327-H肿瘤。根据组织类型的不同，789 nm处的穿透深度是630 nm处的1.35-2.25倍。两种波长之间穿透的最大差异是在高度着色的组织中。红外透过率的大幅增加可能对光动力疗法的未来应用具有重要意义。
New photosensitizers activated by longer wavelengths than 630 nm light used with Photofrin II are under evaluation by various groups for the treatment of malignancies. Any increase in tumour volume destroyed by these agents as compared to Photofrin II will be partly determined by tissue penetrance at the longer wavelengths. Attenuation coefficients were measured for various tissues at 630 nm and the more penetrative near infrared wavelength of 789 nm. A new model of light propagation in tissue is shown to be accurate for arbitrary ratios of absorption and scattering, by comparison with a rigorous solution to the transport equation. Absorption and transport scattering coefficients of tissues at 630 and 789 nm were obtained by fitting this model to optical attenuation measurements. In vitro tissues included bovine heart, kidney and tongue, pig liver and fat, and chicken muscle; in vivo tissues included Dunning R3327-AT and R3327-H tumours. The penetration depth was found to be 1.35-2.25 times greater at 789 than 630 nm, depending on tissue type. The greatest differences in penetration between the two wavelengths were in the highly pigmented tissues. These substantial increases in penetration in the infrared may be important in future applications of photodynamic therapy.