Radiosurgery Treatment of New and Recurrent Glomus Tumors

Introduction: Paragangliomas (PG) or glomus tumors are relatively rare, indolent, vascular tumors that arise from chief cells of the paraganglia. PGs most commonly occur in association with the jugular bulb and comprise 0.6% of intracranial tumors. Two to 5% of PGs secrete catecholamines, 3 to 5% occur at the skull base, and 10 to 15% of lesions occurring in the neck are malignant. Most PGs are sporadic, but 7 to 9% of cases are familial. Traditionally, the standard treatment for these tumors includes microsurgical resection. We sought to analyze our data of PGs treated with Stereotactic Radiosurgery (SRS).

Method: We retrospectively examined the outcomes of 52 PGs in 46 patients treated with SRS at Stanford University. We collected data from medical records, telephone interviews, and imaging studies.

Results: Our retrospective review identified 52 PGs in 46 patients, treated between July 1991 and January 2013. Patients were included if they received SRS alone or SRS as a salvage treatment. Sixty-nine percent of patients were female and 31% were male (36 females, 16 males), and the mean age at treatment was 54.5 years old. Prescribed doses to the periphery of the tumor ranged from 1600 to 2500 cGy (mean of 1999 cGy) using 1 to 5 fractions. Local control rates were 100%, with a mean clinical and radiologic follow-up of 49 months and 40.4 months, respectively. Complications included an increase in pre-existing vertigo in 1 patient, and transient cranial nerve neuropathies in 2 patients.

Conclusions: SRS is a safe and efficacious treatment option for new and recurrent PGs. Given the excellent local control rates and minimal treatment associated morbidity, SRS should strongly be considered a primary treatment option for new and recurrent PGs. Further, fractionated SRS allows for the treatment of large lesions. Microsurgical resection should still be the preferred option in patients who are young, have catecholamine-secreting PGs, or have progressive neurological symptoms. In the case of metastatic PGs, a combination of chemotherapy and SRS or standard radiation therapy should be considered.