Dopamine-secreting carotid body paragangliomas-biochemical control with radiotherapy.

Head and neck paragangliomas that are exclusively or predominantly dopamine-secreting are rare. Surgery and/or radiotherapy are modalities for locoregional tumoral control. Little is known about the efficacy of radiotherapy for biochemical control in such tumors. We report a 62-year-old Chinese man with bilateral carotid body tumors which were exclusively dopamine secreting. The left-sided tumor invaded the skull base and encased the left carotid artery. Surgery was not performed due to high risk of morbidity and mortality. The patient received external beam radiotherapy to bilateral neck regions. Progressive decline and eventual normalization of urinary dopamine excretion was seen together with a slight reduction in tumor size. This is the first report demonstrating the efficacy of radiotherapy for both biochemical and locoregional control of functioning carotid body paragangliomas.