The Optimal Radiation Dose in Localized Head and Neck Diffuse Large Cell Lymphoma

Koom, Woong Sub; Suh, Chang Ok; Kim, Yong Bae; Shim, Su Jung; Pyo, Hongryull; Roh, Jae Kyung; Chung, Hyun Cheol; Kim, Gwi Eon

Abstract

PURPOSE: To determine the optimal radiation dose in a localized non-Hodgkin's lymphoma of the head and neck in the treatment setting for combined chemoradiotherapy.
MATERIALS AND METHODS
Fifty-three patients with stage I and II diffuse large cell non-Hodgkin's lymphoma of the head and neck, who were treated with combined chemoradiotherapy between 1985 and 1998 were retrospectively reviewed. The median age was 49 years, and the male-to-female ratio was approximately 1.6. Twenty-seven patients had stage I disease and 26 had stage II. Twenty-three patients had bulky tumors (> or =5 cm) and 30 had non-bulky tumors (<5 cm). The primary tumors arose mainly from an extranodal organ (70%), most cases involving Waldeyer's ring (90%). All patients except one were initially treated with 3~6 cycles of chemotherapy, which was followed by radiotherapy. Radiation was delivered either to the primary tumor area alone (9%) or to the primary tumor area plus the bilateral neck nodes (91%) with a minimum dose of 30 Gy (range 30~60 Gy). The failure patterns according to the radiation field were analyzed, and the relationship between the dose and the in-field recurrence was evaluated.
RESULTS
The 10-year overall survival and the 10-year disease free survival rates were similar at 75% and 76%, respectively. A complete response (CR) after chemotherapy was achieved in 44 patients (83%). Subsequent radiotherapy showed a CR in all patients. Twelve patients (23%) had a relapse of the lymphoma after the initial treatment. Two of these patients had a recurrence inside the radiation field. No clear dose response relationship was observed and no significant prognostic factors for the in-field recurrences were identified because of the small number of in-field recurrences. However, for patients with tumors <5 cm in diameter, there were no in-field recurrences after a radiation dose 30 Gy. The 2 in-field recurrences encountered occurred in patients with a tumor > or =5 cm.
CONCLUSION
A dose of 30 Gy is sufficient for local control in patients with a non-bulky (<5 cm), localized, diffuse large cell non-Hodgkin's lymphoma when combined with chemotherapy. An additional boost dose in the primary site is recommended for patients with bulky tumors (> or =5 cm).