Current status and perspectives of brachytherapy for head and neck cancer.

Brachytherapy delivers a high radiation dose to a limited volume while sparing surrounding normal tissues. In head and neck cancer, severe soft-tissue damage and bone damage to the mandible has decreased markedly since the introduction of computer dosimetry and the use of spacers during treatment. For the curative treatment of head and neck cancer, the selection of brachytherapy sources from among the several linear and small permanent implant sources available, not only according to the tumor site but also according to the patient's physical and mental condition is important. Following the successful treatment of early head and neck cancer by brachytherapy, two major problems and one minor problem may confront the physician. The major problems are neck node metastasis and a second primary cancer of the respiratory tract or upper digestive tract, and the minor problem is radiation-induced cancer.