Analysis of local control in patients with non-Hodgkin's lymphoma according to the WHO classification

Purpose: to analyze the influence of radiotherapy doses, chemotherapy doses, and clinical parameters on in-field disease control to assess the optimal radiation doses for treatment of non-Hodgkin's lymphoma according to the newly proposed WHO classification. Patients and methods: subjects consisted of 35 extranodal marginal-zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) type, 75 diffuse large B-cell lymphomas (DLBCL), 14 follicular lymphomas, 17 extranodal natural killer (NK)/T-cell lymphomas, nasal type, eight unclassified peripheral T-cell lymphomas, four anaplastic large-cell lymphomas, T/null cell type, and five others. 59 patients received radiotherapy alone. 98 patients received CHOP, modified CHOP, or more intensive chemotherapy, and six patients were treated with other combination. Results: no patients with MALT lymphoma had in-field local recurrence. There were no recurrences in DLBCL patients who received chemotherapy in which the doses of adriamycin were > 200 mg/m2, nor in DLBCL patients who were treated with > 45 Gy. Only nine of 15 patients with T-cell lymphoma treated with ≤ 50 Gy and three of five patients treated with > 50 Gy had local control. The dose of adriamycin had no influence on local control of T-cell lymphoma. Conclusion: T/NK-cell lymphomas were more radioresistant than B-cell lymphomas. The prognosis for peripheral T/NK-cell lymphomas is poor even when treated by irradiation combined with chemotherapy. (orig.)