P10.25.B STIMULATED RAMAN HISTOLOGY FOR INTRAOPERATIVE DIAGNOSIS OF PEDIATRIC BRAIN TUMORS

Abstract BACKGROUND Intraoperative frozen sections are an essential part of neuropathological evaluation during pediatric neurosurgical tumor resections. However, tissue processing and analysis can take up to 45 minutes. Recently, stimulated Raman histology (SRH) has been introduced as a rapid technique for obtaining high-resolution digital images of unprocessed tissue samples directly in the operating room. This study aimed to assess the application of SRH in pediatric brain tumor surgery. MATERIAL AND METHODS Patients aged 18 years or younger undergoing biopsy or resection of a suspected tumor were included. Tissue samples were collected intraoperatively, first examined using SRH directly in the operating room, and subsequently processed for conventional frozen section analysis. A pathologist attempted to classify diagnoses based on SRH images, comparing them with hematoxylin-eosin (HE)-stained sections for mitotic activity, cell density, and vascular density. The representativeness of SRH images was also evaluated. RESULTS A total of 66 patients were included, with a median age of 9.4 years (30 female, 36 male). Based on SRH images, the pathologist was able to correctly establish the diagnosis in 78.8% (52 cases). Incorrect diagnosis was made in 12.1% (8 cases), and in 9.1% (6 cases), a diagnosis could not be made due to the absence of tumor cells in the SRH sample, attributed to a sampling error. The interpretability of mitotic activity was rated as identical between SRH and HE-stained sections in 100% of applicable cases. Cell density was rated correctly in 86.4% (57 cases) whilst vascular density was rated correctly in 93.9% (62 cases). The representativeness of SRH images was rated as high in 59.1% (39 cases), moderate in 30.3% (20 cases), low in 9.1% (6 cases), and non-representative in 1.5% (1 case). CONCLUSION Stimulated Raman histology serves as an important intraoperative diagnostic tool, providing rapid, high-resolution images comparable to conventional frozen section analysis, aiding neurosurgeons in optimizing surgical decision-making.