A new classification and clinical results of Gamma Knife radiosurgery for cavernous sinus hemangiomas: a report of 53 cases

Cavernous sinus hemangiomas (CaSHs) are rare vascular lesions in the cavernous sinus(CS). Gamma Knife radiosurgery (GKS) provides a treatment modality alternative to microsurgery. This study was conducted to describe a new classification of CaSHs based on their magnetic resonance (MR) imaging findings and determine the efficacy and safety of GKS in a large series of CaSH patients.

From April 2007 to November 2012, 53 patients harboring CaSHs were treated using Leksell Gamma Knife model C (before April 2012) or Perfexion (from May 2012 ) at the Gamma Knife Center of Huashan Hospital. Of the 53 patients, 15 with definitive histopathologic diagnoses after surgery, 38 were diagnosed based on their MR imaging findings. There were 15 male and 38 female patients with a mean age of 52 (range, 25–76) years old. The characteristics of MR images of CaSHs were their extremely high homogeneous intensity on T2-weighted and FLAIR images: as bright as cerebrospinal fluid signal. According to the relationship between the carotid line and their location, CaSHs were classified into three types: the intrasellar, parasellar and mixed type. The mean volume of the tumors was 13.2 ± 8.2 cm³ (range, 1–41 cm³). A mean marginal dose of 13.3 Gy (range, 8–15 Gy) was directed to the 49 %–64 % isodose line (mean 53 %).

Of the 53 tumors, 6 (11 %) were classified as intrasellar type. Eight (15 %) were parasellar type and the other 39 cases(74 %) mixed type. The mean radiological and clinical follow-up time of this study was 24 (range, 2–67 months) and 34 months (range, 2–73 months), respectively. The tumor control rate was 100 %. The mean tumor volume reduction was 79.5 % (range, 16.5 %–100 %) compared with the pre-GKS volume. Six months after GKS, MR imaging revealed an average of 60.2 % tumor volume reduction (range, 16.5 %–89.2 %). Twenty-nine cases (55 %) showed a >80 % tumor volume decrease. Neurologically, only two of these patients showed clinical deterioration, and 33 patients demonstrated an obvious improvement in ocular or endocrine disorders. At last follow-up, there were no more complications related to GKS, and none of the tumors progressed.

Our study showed that GKS is a useful and safe therapeutic method for CaSHs as both a primary and adjuvant treatment. The new classification of CaSHs may help predict their clinical course during tumor development and treatment response after GKS. Further studies with long-term follow-up and larger numbers of cases are necessary to optimize the treatment conditions and verify the benefit of this treatment.