Second Window Indocyanine Green
Second Window Indocyanine Green (SWIG) is a novel technique for real-time, intraoperative tumor visualization using a high dose infusion of Indocyanine Green (ICG) 24 hours before surgery. Due to pathologic diversity found in the pineal region, tissue diagnosis in patients with pineal region mass is essential to optimize further clinical management.
Case reports
Cho et al. presented a case of a 75-year-old woman with known pineal region mass for 18 years, who presented with progressive classic signs and symptoms of obstructive hydrocephalus over the past six months. The preoperative imaging confirmed a contrast-enhancing pineal region tumor, which appeared to be obstructing the aqueduct of Sylvius, causing proximal obstructive hydrocephalus. 5mg/kg of ICG was delivered intravenously 24 hours before the surgery. The patient underwent an endoscopic third ventriculostomy and a biopsy of the pineal lesion. The tumor demonstrated clear near-infrared fluorescence which was distinct from surrounding third ventricle floor and ependyma. The signal to background ratio was 2.9. The final pathology report revealed a WHO Grade I pineocytoma.
They reported on a novel application of near-infrared fluorescence for tumor identification of pineal region tumors, using the Second Window ICG technique 1).