Hypofractionated gamma knife radiosurgery for large cavernous sinus hemangiomas: Outcomes of a case series with a review of literature.

Large cavernous sinus hemangiomas (CSHs) present a significant therapeutic challenge. While microsurgery carries risks of massive bleeding and morbidity, standard single-fraction stereotactic radiosurgery is often strictly limited by the radiation tolerance of the adjacent optic apparatus. Data regarding hypofractionated Gamma Knife radiosurgery (HfGKRS) for these lesions remain scarce. This study evaluates the safety and efficacy of a uniform HfGKRS protocol for large CSHs. This retrospective, single-center study analyzed four consecutive patients with large CSHs (median target volume: 25.85 cm³) treated between January 2018 and January 2025. All patients underwent mask-based HfGKRS with a standardized prescription of 25 Gy delivered in five fractions. Treatment response was assessed via volumetric MRI analysis and clinical evaluation. Toxicity was graded according to CTCAE v.5 criteria. Over a median follow-up of 30 months (range: 6–76), all tumors exhibited volumetric reduction relative to baseline, with a median shrinkage of 64% (range: 24.3%–100%). One patient achieved complete radiographic regression. Clinically, all patients demonstrated symptomatic improvement, including two complete recoveries from cranial nerve deficits. Dosimetric analysis confirmed effective sparing of critical structures; median maximum point doses to the optic apparatus (20.1 Gy) and brainstem (17.6 Gy) remained within tolerance limits. No acute or late radiation-induced toxicities were observed. HfGKRS delivering 25 Gy in five fractions appears to be a promising and feasible management strategy for large CSHs. These preliminary results suggest that this regimen can balance tumor control with the preservation of anterior visual pathways, offering a potential treatment alternative when single-fraction dosing is constrained.