Real‑world application of Cytalux for targeted imaging of occult peritoneal disease in epithelial ovarian cancer.

Occult disease in normal-appearing peritoneum is common in epithelial ovarian cancer (EOC), especially after neoadjuvant chemotherapy (NACT). Pafolacianine (Cytalux) is the first Food and Drug Administration-approved agent for targeted imaging of EOC occult disease. The current study presents its first out-of-trial use during cytoreductive surgery (CRS). This study analyzed three cases of Cytalux application in patients with EOC and peritoneal metastases who underwent CRS and hyperthermic intraperitoneal chemoperfusion. Targeted imaging with Cytalux was performed before CRS to confirm uptake by visible lesions and after to identify occult disease. The association between Cytalux-positive disease and pathology was evaluated. Patient A had primary EOC and patients B and C had recurrent disease. All patients received NACT. Patient A had a peritoneal cancer index (PCI) of 21 and a completeness of cytoreduction (CC) score of 1, while patients B and C both had PCI 9 and CC score of 0. Cytalux imaging was associated with all macroscopic lesions. In patient A, Cytalux identified 16 additional peritoneal lesions with 14 confirmed as metastases [true positive (TP) rate, 87.5%]. Two Cytalux-positive peritoneal areas were fulgurated until the signal loss but subsequently tested positive for cancer. In patients B and C, Cytalux detected two lesions in each case with 50.0% positive on pathology. Overall peritoneal-level TP and false positive (FP) rates were 80.0 and 20.0%, respectively. Cytalux can help identify occult EOC peritoneal disease and manage questionable areas of post-chemotherapy fibrosis. However, the FP rate is considerable. Cytalux signal navigation should not be used for energy destruction of lesions until more data are available.