[Results of radiation therapy of extranodal non-Hodgkin's lymphoma of the head and neck--a study of the Japan Lymphoma Radiation Therapy Study Group].

During the years 1972-81, 168 patients with extranodal Non-Hodgkin's lymphoma localized in the head and neck were treated with radiation. Five-year survival rates were 62% in stage I, 56% in stage II, and 91% in diffuse well-differentiated lymphocytic, 77% in diffuse mixed, 52% in diffuse poorly-differentiated lymphocytic and diffuse histiocytic each. Marginal relapse was rare after radiation therapy, but relapses were not infrequently noticed in distant extranodal sites. Bone and/or soft tissue relapses were frequently noticed in patients with lesions initially located in the nasal cavity, paranasal sinus and oral cavity.