Radiation Therapy for Solitary Fibrous Tumor of the Orbit.

Solitary fibrous tumor, formerly also referred to as hemangiopericytoma, is a fibroblastic mesenchymal neoplasm of the orbit that rarely metastasizes but has a propensity for local recurrence. We describe 5 cases of orbital solitary fibrous tumors that were treated with radiation. In 3 patients, radiation therapy was given in the neoadjuvant setting prior to surgery. In the remaining 2 patients, radiation was used palliatively in patients who declined surgery. In 4 of 5 cases, a measurable reduction in the size of the orbital mass was observed in response to radiation therapy; however, long-term adverse effects of radiation may not yet be evident, given the relatively short follow-up period for some of the patients in this report.