title: Single-fraction stereotactic radiosurgery of meningeal hemangiopericytomas.
abstract: Meningeal hemangiopericytomas (M-HPC) are challenging tumors with a high rate of recurrence despite surgical resection and external beam radiotherapy (EBRT). To better understand the role of single-fraction stereotactic radiosurgery (SRS) for patients with M-HPC, we reviewed our experience with 22 patients (12 men, 10 women) from 1990 until 2010. Twelve patients (55%) underwent a single SRS procedure, whereas 10 patients (45%) had more than one SRS procedure (range 2-6). In total, 47 SRS procedures were performed to treat 64 tumors. Fourteen patients (64%) had undergone prior EBRT (median dose, 56.0 Gy). Follow-up after the initial SRS (median, 66 months) was censored at the time of death (n = 15) or last clinical evaluation (n = 7). Eleven patients (50 %) died of intracranial tumor progression (n = 10) or treatment-related complications (n = 1). One patient (5%) died of systemic disease progression. Disease-specific survival (DSS) at 1-, 3- and 5-years after SRS was 96, 82, and 61%, respectively. Prior EBRT (HR 9.0, 95% CI 1.1-78.1, p < 0.05) and larger initial tumor volume (HR 1.09, 95% CI 1.02-1.2, p = 0.02) were associated with worse DSS. Local tumor control (LTC) after SRS at 1-, 3-, and 5-years was 89, 68, and 59%, respectively. Improved LTC was noted in patients who had not undergone prior EBRT (HR 6.3, 95% CI 2.1-19.5, p = 0.001). One patient (5%) had symptomatic radiation-relation complications after SRS. Overall, single-fraction SRS was effective in providing LTC for more than half of recurrent or residual M-HPC at 5-years after the procedure. Repeat SRS is often required secondary to either distant or local tumor progression.
authors.affiliation: Department of Neurological Surgery, Mayo Clinic College of Medicine, Rochester, MN, 55905, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Copeland
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Link
authors.forename: Scott L
authors.initials: SL
authors.lastname: Stafford
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Pollock
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019583:Dose Fractionation, Radiation; D005260:Female; D005500:Follow-Up Studies; D006393:Hemangiopericytoma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008875:Middle Aged; D009367:Neoplasm Staging; D011183:Postoperative Complications; D011379:Prognosis; D016634:Radiosurgery; D015996:Survival Rate; D047368:Tumor Burden