5-aminolevulinic acid-induced (ALA) fluorescence for the laparoscopic diagnosis of peritoneal metastasis - 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 10(3) ovarian adenocarcinoma cells in the peritoneum o f 31 rats. One week later, 5-aminolevulinic acid was injected in the perito neum (100 mg/kg). After 3 h, we examined the rats using a 10-mm endoscope w ith a mono CCD camera and a light source developed for photodynamic diagnos is. Metastases on the parietal peritoneum were evaluated independently by t wo surgeons randomly assigned to use either a conventional light mode or th e 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). Met astases diagnosed by fluorescence were confirmed by pathologic examination. Random peritoneal biopsy specimens taken from nonfluorescent areas were ne gative. Conclusion: In this experiment, ALA-induced fluorescence improved the detec tion of peritoneal metastases of ovarian cancer.