• 5-aminolevulinic acid photodynamic diagnosis (PDD) detected occult ovarian cancer. • PDD distinguished malignant lesions within ambiguous post-chemotherapy scarring. • Fluorescence-guided surgery facilitated detection of missed miliary tumors. • Histopathological analysis confirmed malignancy in 100% of fluorescent sites. • PDD may enhance cytoreduction during interval debulking surgery (IDS). 5-aminolevulinic acid (5-ALA) photodynamic diagnosis (PDD) facilitates intraoperative identification of malignant lesions. While established in bladder and brain tumors, its utility in advanced ovarian cancer remains limited, particularly for identifying residual disease within post-chemotherapy scarring during interval debulking surgery (IDS). We report a case where 5-ALA PDD identified occult tumors during both diagnostic laparoscopy and IDS. A 74-year-old woman with stage IVB high-grade serous ovarian carcinoma underwent diagnostic laparoscopy followed by three cycles of neoadjuvant chemotherapy (NAC). During subsequent IDS, 5-ALA PDD was employed alongside standard white light imaging. PDD identified peritoneal disseminations that were invisible under white light. Notably, PDD successfully detected viable malignant foci within fibrotic, scar-like lesions modified by NAC, which were otherwise indistinguishable. Although suboptimal debulking was performed due to unresectable nodules near the pancreas, histopathological analysis confirmed malignancy in 100% of PDD-positive sites. No 5-ALA-related adverse events occurred. 5-ALA PDD may enhance the accuracy of cytoreduction in advanced ovarian cancer by facilitating the detection of residual viable tumors within post-chemotherapy scarring. This technique offers significant diagnostic value in the NAC-IDS setting where conventional inspection is often limited.
Nakamoto et al. (Wed,) studied this question.