External beam radiation therapy in the treatment of patients with extranodal stage IA non-Hodgkin's lymphoma

The purpose of this report was to study the results of external beam radiotherapy for patients with extranodal stage IA non-Hodgkin's lymphoma (NHL). A retrospective review was carried out on 27 patients seen between 1984 and 1998 with stage IA NHL of extranodal sites, and followed up for a minimum of 1 year. Sites involved included eye/orbit (seven), parotid (five), breast (four), Waldeyer ring (four), thyroid (three), other head and neck (two), stomach (one), and prostate (one). All patients had biopsy-proven disease and underwent staging workup to rule out other sites of disease. Histologic analysis revealed 16 patients with low-grade NHL, 9 with intermediate-grade, and 2 with high-grade. Ten patients received chemotherapy before radiation therapy, and eight of them had a complete response. The remaining 17 patients were treated with external beam radiation therapy alone. Radiation was directed to the involved field at 1.8 Gy to 2.0 Gy per fraction to a median dose of 40 Gy (range: 20-50.4 Gy). The median patient age was 71 years (range: 39-85 years); 55% were female, and 45% were male. A complete response was attained in all 27 patients after radiation therapy. There were five failures (all in uninvolved distant sites), and two deaths during the follow-up. Median disease free survival (DFS) and overall survival (OS) have not been reached. The 5-year DFS and OS are 85% and 94%, respectively. Older age at presentation showed a trend toward worse outcome (p = 0.07), but because of the relatively few events, other factors (radiation dose, grade of disease, sex, or the use of chemotherapy) showed no statistical differences among the patients. External beam radiation therapy is a highly effective treatment for stage IA NHL found in extranodal sites.