5-aminolevulinic acid-induced (ALA) fluorescence for the laparoscopic diagnosis of peritoneal metastasis. AST An experimental study.

Background: We performed a randomized experimental study in a rat model to evaluate the use of 5-aminolevulinic acid-induced (ALA) fluorescence in the laparoscopic diagnosis of peritoneal metastases of ovarian cancer.

Methods: We injected 103 ovarian adenocarcinoma cells in the peritoneum of 31 rats. One week later, 5-aminolevulinic acid was injected in the peritoneum (100 mg/kg). After 3 h, we examined the rats using a 10-mm endoscope with a mono CCD camera and a light source developed for photodynamic diagnosis. Metastases on the parietal peritoneum were evaluated independently by two surgeons randomly assigned to use either a conventional light mode or the fluorescence mode.

Results: The mean number of metastases detected was 2.84 with conventional laparoscopic light and 5.74 with ALA-induced fluorescence (p < 0.0008). Metastases diagnosed by fluorescence were confirmed by pathologic examination. Random peritoneal biopsy specimens taken from nonfluorescent areas were negative.

Conclusion: In this experiment, ALA-induced fluorescence improved the detection of peritoneal metastases of ovarian cancer.