Irradiation of clinically uninvolved cervical lymph nodes

Of 402 patients with cancers of the oral cavity, oropharynx, and supraglottic larynx treated at Stanford between 1957 and 1972, 164 had clinically uninvolved cervical lymph nodes prior to the initiation of radiation therapy. Lymph node metastases developed later in 38 per cent of patients with primary oral cavity carcinomas who were treated with interstitial radium implants alone. No late cervical lymph node involvement was found in those patients who received high dose external irradiation to at least the primary site and first echelon lymph nodes. Lymph node failures were ultimately noted in 20 of the 140 patients (14 per cent), who received partial or complete neck irradiation, but 18 of these occurred in patients with uncontrolled primary lesions, suggesting that re-seeding of cervical lymph nodes had taken place rather than failure of the initial irradiation to control subclinical metastases. Our present policy is to treat the primary lesion and adjacent lymph nodes with high dose megavoltage techniques, combined with interstitial irradiation if possible. Bilateral supplemental inferior neck radiation ports are added for patients with advanced primary neoplasms and for those with clinically involved cervical lymph nodes. All other patients undergoing radiation therapy for stage T1 primary lesions and clinically negative necks also receive ipsilateral low neck irradiation. In addition, cervical lymph nodes are electively irradiated when the primary lesion has been resected. When these policies are adopted, the incidence of cervical lymph node failures is extremely low in patients whose primary sites remain controlled, and morbidity from the cervical radiation fields is negligible.