Arnfield M R, Chapman J D, Tulip J, Fenning M C, McPhee M S
Department of Surgery, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta, Canada.
Photochem Photobiol. 1993 Feb;57(2):306-11. doi: 10.1111/j.1751-1097.1993.tb02292.x.
The optical properties of tumor tissue provide important information for optimizing treatment plans in photodynamic therapy, especially when interstitial application by multiple fibers is planned. Near infrared light, required to activate novel photosensitizers, should facilitate improved light penetrance of tumor tissue compared with 630 nm light used for activating Photofrin II. We have measured light energy fluence rates for 630 and 789 nm light along radial tracks from a single laterally diffusing optical fiber centrally implanted into Dunning R3327-AT and R3327-H rat prostate tumors in anesthetized rats. A total of 20 R3327-AT and 10 R3327-H tumors were used in this study with volumes from 2.6 to 13.3 cm3. Light track data were analyzed by an empirical model that described light attenuation. At 630 nm, light attenuation coefficients (LAC) were approximately 1.9 x higher than those at 789 nm for both tumors with the well-differentiated, well-perfused tumor (R3327-H) attenuating to a greater extent than did the rapidly growing anaplastic tumor (R3327-AT). The intertumor variation of LAC was greater than the spatial variations observed within individual tumors. LAC were a function of tumor volume for only 630 nm light in the R3327-AT tumors.
肿瘤组织的光学特性为优化光动力疗法的治疗方案提供了重要信息，尤其是在计划通过多根光纤进行间质应用时。与用于激活卟吩姆钠II的630nm光相比，激活新型光敏剂所需的近红外光应有助于提高肿瘤组织的光穿透率。我们已经测量了沿着从一根横向扩散的单光纤中心植入麻醉大鼠的Dunning R3327-AT和R3327-H大鼠前列腺肿瘤的径向轨迹的630和789nm光的光能注量率。本研究共使用了20个R3327-AT肿瘤和10个R3327-H肿瘤，体积从2.6到13.3cm³。通过描述光衰减的经验模型分析光轨迹数据。在630nm处，两种肿瘤的光衰减系数（LAC）均约比789nm处高1.9倍，分化良好、灌注良好的肿瘤（R3327-H）比快速生长的间变性肿瘤（R3327-AT）衰减程度更大。LAC的肿瘤间差异大于单个肿瘤内观察到的空间差异。仅在R3327-AT肿瘤中，LAC是630nm光的肿瘤体积的函数。
