Intracranial hemangiopericytoma: long-term surgical outcomes

BACKGROUND: According to 2021 WHS Classification, intracranial hemangiopericytomas or solitary fibrous tumors are rare meningeal neoplasms involving blood vessels and soft tissues. Such neoplasms are commonly classified as malignant due to their aggressive growth, metastasizing beyond the cranial cavity, and frequent recurrencies. Since these tumors rarely occur in neurosurgical patients, publications in Russian do not cover big cohorts of patients whose conditions would be assessed during both early and late observation periods.

AIM: The present study analyzed our experience in surgical treatment of hemangiopericytomas and its long-term results.

METHODS: The study was arranged as a single-center, pro-and retrospective trial that included hemangiopericytomas patients (n=17), whose tumors of different grades of malignancy (1–3) were operated at the Federal Neurosurgical Center in Novosibirsk from 2013 to 2021. The follow-up estimates included survivability; physical status (Karnofsky’s Scale); radicality; metastatic foci; need for postoperative chemo-and radiation therapy; adjuvant therapy effect on patients’ survivability, and delaying time to relapse.

RESULTS: In total, 17 patients were included. 11 of them underwent total hemangiopericytomas removal (65%), and 6 — subtotal removal (35%). Their survivability within the first year after the operation was 100%. As for the 5-year follow up, only 8 patients out of 17 were available, their mean observation time comprising 64.7 months. The 5-year survivability was 75% (6 out of 8 patients). A relapse occured in 3 out of 17 (17.5%). The mean delaying time comprised 67 months. 6 out of 17 patients (35%) underwent radiation therapy. Among the patients with total and subtotal removals who underwent postoperative radiation treatment neither a relapse nor tumor growth nor metastases were found.

CONCLUSION: Intracranial hemangiopericytoma is a rare malignant space-occupying neoplasm. Considering our experience and published data, its treatment requires aggressive tactics that includes a radical removal of the tumor followed by early irradiation of the tumor’s residual volume or bed either in a proton accelerator or a gamma-knife facility notwithstanding its malignancy grade. It is also recommended to extend the follow-up period for such patients to 10–15 years that should include annual cancer screening to detect local relapses and metastases.