Chemodectoma of the carotid body treated with radiation therapy: a case report.

The response to radiation of a huge chemodectoma arising in the carotid body is reported. Diagnostic imaging and a resected specimen demonstrated a rich supply of blood vessels in the tumor. A radiation dose of 40 Gy was applied to the tumor over four weeks with a 10 megavolt photon beam. The tumor had a non-enhanced area in the middle 1.5 years after radiation therapy. The whole tumor as well as the non-enhanced area was obviously shrunken three years after treatment.