Radiation therapy for subclinical carcinoma in cervical lymph nodes.

Radiotherapy alone was used to treat 187 patients with a head and neck cancer and clinically uninvolved lymph nodes. Delayed lymph node metastases developed in 35 (19%) patients, and concomitant tumor at the primary site was present in 90% of them. In two (1%) of the 187 patients, delayed metastases developed in the irradiated nodes with the primary tumor controlled; both of these patients received a radiation dose of less than 5,000 rad. Metastases in supraclavicular and posterior cervical regions occurred in 4% of the patients; and these sites were not included in the original radiation fields. The following conclusions were reached: (1) a radiation dose of 5,000 rad or more can eradicate 99% of the subclinical carcinomas in lymph nodes; (2) whole-neck irradiation is not indicated in patients with N0 stage tumor; and (3) surgical resection of primary tumors alone, without added neck dissection, may be adequate if postoperative radiation therapy is planned.