Fractionated stereotactic conformal radiotherapy in the management of large chemodectomas of the skull base

PURPOSE: To evaluate the role of fractionated stereotactic conformal radiotherapy (FSRT) as a noninvasive method in the management of large chemodectomas of the skull base. METHODS AND MATERIALS: Twenty-two patients with chemodectomas of the skull base were treated with FSRT at our institution. Ten patients received primary RT, and 12 patients were treated for recurrent or progressive disease after primary surgery (8 patients) or embolization (4 patients). The median total dose was 57.6 Gy, with a median of 1.8 Gy/fraction. The median target volume was 71.8 cm3 (range, 10.5-212.2 cm3). The most common symptoms at the initial diagnosis were pulsatile tinnitus (16 patients), hearing loss (14 patients), and balance disturbance (14 patients). Twelve patients had additional cranial nerve deficits. RESULTS: The median follow-up was 5.7 years (range, 19-177 months). The actuarial overall survival rate was 89.5% at 5 and 10 years. The actuarial local control rate was 90.4% at 5 and 10 years. Seven patients (32%) had a partial response and 13 (59%) had stable disease of the irradiated chemodectoma. Two symptomatic patients developed recurrence after 19 and 32 months. Neurologic dysfunction improved or completely resolved in 59% and stabilized in 32%; 9% of patients experienced impairment of preexisting neurologic dysfunction. No patient developed new neurologic deficits after FSRT. RT was interrupted in 1 patient because of a maxillary bone abscess. In all other patients, no acute or late adverse reactions greater than Common Toxicity Criteria Grade 2 were seen. CONCLUSION: Fractionated stereotactic conformal radiotherapy is an effective and well-tolerated noninvasive treatment for chemodectomas, with excellent tumor control rates and a low risk of morbidity. It is an option for patients at greater risk of microsurgical resection or with residual and recurrent tumors.