Intraoperative Differentiation of Pilocytic Astrocytoma and Hemangioblastoma with Indocyanine Green Video Angiography

Purpose Differentiating between pilocytic astrocytomas (PA) and hemangioblastomas (HB) during surgery is challenging due to their radiological similarities but distinct vascular characteristics and surgical considerations. This study explores the application of indocyanine green (ICG) fluorescence angiography for intraoperative differentiation of these tumors. Methods Four patients with cerebellar cystic masses underwent surgical resection using ICG video angiography. ICG fluorescence patterns were observed intraoperatively to distinguish vascular characteristics. Homogeneous enhancement in HB was hypothesized to contrast with the nonenhancing nodules of PA. The findings were correlated with preoperative imaging and histopathology. Results In cases of HB, ICG angiography demonstrated early-phase homogeneous fluorescence, highlighting the tumor’s high vascularity and aiding complete resection while preserving vascular integrity. In contrast, PA showed no fluorescence in the tumor nodule, enabling piecemeal resection with minimal blood loss. Histopathological diagnoses confirmed the intraoperative findings. The technique was safe, with no complications reported. Conclusion This study demonstrates the utility of ICG video angiography as an intraoperative adjunct for differentiating PA from HB. Compared with digital subtraction angiography, ICG offers a cost-effective, safe, and efficient alternative, without the need for specialized equipment or radiation exposure. ICG fluorescence enhances intraoperative decision-making and optimizes surgical outcomes for challenging posterior fossa lesions. Further studies are warranted to validate these findings and expand the role of ICG in neurosurgical practice.