Staging Fluorescence Laparoscopy for Gastric Cancer by Using 5-Aminolevulinic Acid

Background: Precise staging of gastric cancer is essential when selecting for the appropriate treatment approach. 5-Aminolevulinic acid (5-ALA) is metabolized and accumulated as protoporphyrin IX (PpIX), which is a photosensitizer. In this study, we evaluated the diagnostic usefulness of 5-ALA for demonstrating peritoneal dissemination in patients with gastric cancer. Materials and Methods: Fluorescence laparoscopy (FL) was performed in 13 patients with gastric cancer. All patients received preoperative oral administration of 5-ALA. Fluorescence-light laparoscopies were sequentially performed intraoperatively. Results: In four out of the 13 patients, primary tumors were detected by FL and demonstrated serosal invasion on histological examination. Five out of the 13 patients demonstrated peritoneal metastases, and one patient demonstrated superficial liver micrometastases, by FL. All of these lesions were diagnosed as metastatic lesions by hematoxylin and eosin staining. Conclusion: These findings show that FL diagnosis with 5-ALA is accurate and suitable for the detection of peritoneal metastases and of superficial liver micrometastases in patients with gastric cancer.