Webber J, Kessel D, Fromm D
Department of Surgery, Wayne State University School of Medicine, Detroit, MI 48201, USA.
J Photochem Photobiol B. 1997 Apr;38(2-3):209-14. doi: 10.1016/s1011-1344(96)07445-3.
It is important to have a frame of reference for the timing of photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) so that PDT can occur when the tissue levels of protoporphyrin IX (PP) are at a maximum. This study describes a non-invasive fluorescence technique for detecting tissue PP levels after systemic ALA administration in patients with gastrointestinal cancer. The data suggest that the intensity of tumor surface fluorescence correlates with the tumor PP concentration. Spectrophotofluorometric measurements of skin and buccal mucosa also offer an easily acquired and rapid means for determining changes in plasma concentrations of PP. A number of potential variables, including blood flow, affect the intensity of fluorescence. We report that fluorescence measurements in situ are best adapted to the measurement of changes in the porphyrin levels in tissues rather than the absolute concentrations.
对于使用5-氨基酮戊酸（ALA）进行光动力疗法（PDT）的时间安排而言，拥有一个参考框架很重要，这样在原卟啉IX（PP）的组织水平达到最大值时PDT才能进行。本研究描述了一种用于检测胃肠道癌患者全身给予ALA后组织PP水平的非侵入性荧光技术。数据表明肿瘤表面荧光强度与肿瘤PP浓度相关。皮肤和颊黏膜的分光荧光测量也提供了一种易于获取且快速的方法来确定PP血浆浓度的变化。包括血流在内的许多潜在变量会影响荧光强度。我们报告原位荧光测量最适合用于测量组织中卟啉水平的变化而非绝对浓度。
