Intracranial Hemangiopericytomas: Recurrence, Metastasis, and Radiotherapy

Abstract

Background Intracranial hemangiopericytomas (HPCs) are characterized by high recurrence rates and extracranial metastases. Radiotherapy provides an adjunct to surgery, but the timing of therapy and the patients most likely to benefit remain unclear. Methods A retrospective review of 20 patients with HPC treated at the University of Texas Southwestern Medical Center between 1985 and 2014 was conducted. Recurrence and metastasis rates along with overall survival (OS) were characterized based on therapeutic approach and tumor pathology using Kaplan-Meier and Cox regression analyses. Results The mean age was 45.6 years (range: 19-77). Gross total resection (GTR) was achieved in 13 patients, whereas 5 patients underwent subtotal resection. Median follow-up was 91.5 months (range: 8-357). The 5-, 10-, and 15-year recurrence-free survival (RFS) rates were 61, 41, and 20%, respectively. Six patients developed metastases at an average of 113 months (range: 42-231). OS at last follow-up was 80%. Importantly, immediate postoperative adjuvant radiotherapy (IRT) did not influence RFS compared with surgery alone or OS compared with delayed radiotherapy at the time of recurrence. Conclusion HPCs have high recurrence rates necessitating close follow-up. Surgery remains an important first step, but the timing of radiotherapy for optimal control and OS remains uncertain.

Keywords: hemangiopericytoma; intracranial; radiotherapy; recurrence; survival.

Fig. 1

Kaplan-Meier curves for recurrence-free, metastasis-free, and overall survivals for the patient cohort. Ten-year actuarial rates for recurrence-free, metastasis-free, and overall survivals were 41, 73, and 73%, respectively.

Fig. 2

Kaplan-Meier curves of recurrence-free survival by tumor location. C, convexity; P, parasagittal; SB, skull base. Recurrence-free survival trended higher in parasagittal tumors compared with convexity lesions (hazard ratio [HR] 8.03 with 95% confidence interval [CI] 0.91–70.46, p  = 0.06).

Fig. 3

Kaplan-Meier curves of metastasis-free (hazard ration [HR] 6.94 with 95% confidence interval [CI] 0.17–287.13, p  = 0.31) and overall survivals (HR 1.11 with 95% CI 0.33–3.74, p  = 0.87) with respect to timing of radiotherapy. DRT, delayed radiotherapy at the time of recurrence; IRT, immediate postoperative radiotherapy.

Fig. 4

Kaplan-Meier curves of progression-free survival after retreatment of recurrent hemangiopericytomas. There was no difference between surgery plus radiotherapy (S + RT) and radiotherapy alone (RT; hazard ratio [HR] 2.05 with 95% confidence interval [CI] 0.59–7.09, p  = 0.26).

Fig. 5

Treatment algorithm for a patient who presents with a homogenously enhancing dural-based mass on magnetic resonance imaging (MRI). FLAIR, fluid-attenuated inversion recovery.