Introduction/Background Interval debulking surgery (IDS) has similar outcomes and less morbidity in comparison with primary debulking in advanced ovarian cancer, however, there is controversy regarding the selection of chemotherapy-resistant clones. Complete resection (CR) is an essential prerequisite and near-infrared surgery (NIS) combined with various techniques for highlighting malignant foci is striving to achieve true CR. This study investigated the role of Indocyanine Green (ICG) for identifying residual malignant foci during IDS.

Methodology Patients that agreed and underwent IDS were included between 2020–2022. A bolus of ICG was administered and suspect peritoneal samples in NIR (defined by ICG hyper-/hypointensity in comparison with background ICG using Zeiss Pentero 800) were excised.

Results Fifteen patients were included, with a median age at diagnosis of 56 years (range 38–71). Fourteen patients (93.33%) had a high-grade serous carcinoma and most cases (73%) were FIGO stage III. All patients underwent 4 to 7 cycles of neoadjuvant platinum based chemotherapy. Forty per cent of regimens associated Bevacizumab. Six patients (40%) had a BRCA mutant variant and the median interval between neoadjuvant chemotherapy and IDS was 42 days (range 20–78 days). A total number of 39 suspect additional peritoneal samples were analyzed, with 41% confirming malignant foci. Positivity for malignant foci was confirmed on 4 out of 13 (30%) ICG hyperintense areas and 12 out of 26 (46%) ICG hypointense areas (OR 1.93, 95%CI 0.47–7.88).

Conclusion The use of ICG was associated with an increase in the resection of samples with residual malignant foci. Overall, hypointense ICG areas had a higher positivity rate for malignant foci in comparison with hyperintense ICG areas (46% vs. 30%), which could be interpreted in the context of dynamic changes in the tumor microvasculature or different patterns of tumor remodeling following neoadjuvant chemotherapy, that needs to be validated in larger cohorts.