Quantification of Tumor Blush of Highly Vascularized Tumors with Slow Feeding System: Representative Use for Giant Pituitary Adenomas

Background Modern imaging techniques can identify adverse factors for tumor removal such as cavernous sinus invasion before surgery, but surgeries for giant pituitary adenomas often reveal discrepancies between preoperative imaging and intraoperative findings because pituitary adenomas have feeding arteries with narrow diameters. Current imaging methods are not suitable for tumors with not only large vascular beds but also slow arterial filling. Patients and Methods This prospective study recruited 13 male subjects and 9 female subjects with giant pituitary adenomas between November 2011 and 2018. All the patients were investigated with three-dimensional magnetic resonance (MR) imaging, bone image computerized tomography (CT), and digital subtraction angiography (DSA) using a C-arm cone-beam CT scanner with a flat-panel detector and 50% diluted contrast medium. Fine angioarchitecture was evaluated and the tumor blush was quantified using newly developed region of interest (ROI) analysis to establish surgical strategies. Results Seven patients demonstrated no or very faint tumor blushes. In these patients, feeding arteries run centripetally from the surface of the tumor. Fifteen patients showed significant tumor blushes, and the feeding arteries penetrated centrifugally from the inferoposterior pole to the upper pole of the tumor. All the patients were treated according to the angiographic information with successful hemostasis. The patients showed improvement and/or disappearance of the neurologic deficits. The faint and significant blush groups showed significant differences in intraoperative bleeding ( p < 0.01) and operation time ( p < 0.05). Conclusion Specialized evaluation focused on vascularization is required for successful therapy of giant pituitary adenomas.