Kriegmair M, Baumgartner R, Knuechel R, Steinbach P, Ehsan A, Lumper W, Hofstädter F, Hofstetter A
Department of Urology, University of Munich, Germany.
Urology. 1994 Dec;44(6):836-41. doi: 10.1016/s0090-4295(94)80167-3.
Tiny papillary tumors and flat urothelial lesions such as dysplasia or carcinoma in situ can easily be missed during routine cystoscopy. Various methods for in vivo detection of fluorescing agents (preferentially localized in malignant tissue) have been developed. Most of them are based on systemically administered synthetic porphyrin compounds and require sensitive detection devices and image processing units for fluorescence visualization. The usefulness of intracellularly accumulated endogenous protoporphyrin IX (PPIX), induced by 5-aminolevulinic acid (ALA), for diagnosis of early bladder cancer and the correlation with cystoscopic, microscopic, and fluorescence findings was investigated.
ALA was instilled intravesically in 68 patients, followed by fluorescence cystoscopy with violet light from a krypton ion laser that produced fluorescence excitation. There were 299 biopsies obtained from fluorescing and nonfluorescing areas of the bladder.
ALA-induced fluorescence could be easily observed with the naked eye during cystoscopy under violet light illumination. All tumor lesions were sharply marked with brightly shining red fluorescence. Correlation of fluorescence and microscopic findings gave a sensitivity of 100% and a specificity of 68.5%. There were 26 malignant or precancerous lesions that were missed during routine cystoscopy but were detected only by ALA-induced fluorescence.
Labeling of urothelial lesions by PPIX fluorescence induced by intravesically instilled ALA seems to be a promising diagnostic procedure for malignant lesions that are difficult to visualize with standard cystoscopy.
微小乳头状肿瘤以及扁平尿路上皮病变，如发育异常或原位癌，在常规膀胱镜检查时很容易被漏诊。已开发出多种用于体内检测荧光剂（优先定位于恶性组织）的方法。其中大多数基于全身给药的合成卟啉化合物，并且需要灵敏的检测设备和图像处理单元来进行荧光可视化。研究了由5-氨基酮戊酸（ALA）诱导的细胞内积聚的内源性原卟啉IX（PPIX）对早期膀胱癌诊断的有用性及其与膀胱镜检查、显微镜检查和荧光检查结果的相关性。
对68例患者进行膀胱内灌注ALA，随后用氪离子激光发出的紫光进行荧光膀胱镜检查以产生荧光激发。从膀胱的荧光区和非荧光区获取了299份活检标本。
在紫光照射下的膀胱镜检查过程中，肉眼很容易观察到ALA诱导的荧光。所有肿瘤病变均被明亮的红色荧光清晰标记。荧光与显微镜检查结果的相关性显示敏感性为100%，特异性为68.5%。有26例恶性或癌前病变在常规膀胱镜检查时被漏诊，但仅通过ALA诱导的荧光被检测到。
膀胱内灌注ALA诱导的PPIX荧光对尿路上皮病变进行标记，对于标准膀胱镜难以可视化的恶性病变似乎是一种有前景的诊断方法。
