[Radiotherapy of primary extranodal non-Hodgkin's lymphoma of the head and neck region. Results of a prospective multicenter study. Study Group NHL: early studies].

Purpose: To evaluate the long-term outcome of patients with limited-stage primary extranodal lymphoma of head and neck treated with definitive radiotherapy in low-grade and a combined radio- and chemotherapy in high-grade lymphoma.

Patients And Methods: Between January 1986 and August 1993, 63 patients with primary extranodal Non-Hodgkin lymphoma of head and neck region, stages IE and IIE were treated with radiotherapy. The histological classification followed the Kiel classification, staging the Ann Arbor classification.

Patient Characteristics: 33 male, 30 female; age 18 to 84 years; tumor localisation: tonsils 26, nasopharynx 7, oropharynx 8, paranasal sinus 11, salivary glands 7, floor of mouth/gingiva 3, larynx 1. Mean follow-up is 74 months. Low-grade lymphoma in stages I and II CS were treated with definitive radiation therapy according to the concepts of epithelial tumors of the same localisation (target volume and technique). The adjuvant dose was 30 Gy and in the tumor volume 40 Gy, 2 Gy daily. 28 patients were registered, 18 in stage I and 10 in stage II. High-grade lymphoma were treated with definitive radiation therapy according to the concepts of epithelial tumors of the same localisation, too. The dose was 40 respectively 50 Gy, followed by 4 courses of adjuvant chemotherapy with CHOP. Thirty-five patients were enrolled, of whom only 10 received chemotherapy.

Results: The overall 5-year survival rates were for low-grade 67% and for high grade lymphoma 88%. The corresponding relapse-free survival rates were 54/68%, respectively. Only 1 patient failed within the irradiated target volume. Recurrences occurred at sites distant to the irradiated volume in nodal and extranodal regions. Prognosis was influenced by histologic grade. Significant trends were not observed for other potential pretreatment parameters (age, stage, localisation, bulk).

Conclusions: In stage I or II patients with low malignant non-Hodgkin's lymphoma of the head and neck, initial management with definitive external radiotherapy is appropriate and probably curative. In high-grade lymphoma of clinical stage IE with nonextensive tumor size definitive radiotherapy is possible in curative intention. Primary chemotherapy followed by radiation is probably preferable.