Direct comparison of 5-aminolevulinic acid photodynamic diagnosis and white light inspection for detecting peritoneal dissemination in advanced ovarian cancer: a pilot study.

Abstract

Objective: Protoporphyrin IX, a metabolite of 5-aminolevulinic acid (5-ALA), emits red fluorescence. Photodynamic diagnosis (PDD) using 5-ALA has been successfully applied in fluorescence-guided surgery for various malignancies. This pilot study directly compared the diagnostic performance of conventional white light (WL) inspection and 5-ALA-based PDD for detecting intraperitoneal dissemination in advanced ovarian cancer (OC).

Methods: This prospective single-center study included patients with advanced OC undergoing staging laparoscopy. Each patient received oral 5-ALA (20 mg/kg) 4 hours preoperatively. Tumor and non-tumor locations were identified under WL and fluorescent light (FL). Biopsy specimens were collected from tumor locations visible under both WL and FL, only under WL, and only under FL and from non-tumor locations visible under both WL and FL. Pathological examination confirmed malignancy, and results were correlated with imaging findings.

Results: Seven patients were enrolled between January and March 2019 and 71 biopsies were performed. The diagnoses included four cases of high-grade serous carcinoma, one clear cell carcinoma, one grade 3 endometrioid carcinoma, and one pseudomyxoma peritonei. The sensitivity, specificity, positive predictive value, and negative predictive value for detecting malignancy under WL were 87.8%, 59.0%, 82.7%, and 68.4%, respectively, compared with 96.0%, 90.5%, 96.0%, and 90.5% under FL. Additional metastatic lesions were identified in three patients subjected to 5-ALA imaging. No severe 5-ALA-related adverse events were observed.

Conclusion: 5-ALA-based PDD demonstrated higher diagnostic accuracy than WL for detecting intraperitoneal dissemination of advanced OC. Its ability to enhance tumor detection may improve surgical precision and outcomes.