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

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.

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.

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/m(2), nor in DLBCL patients who were treated with > 45 Gy. Only nine of 15 patients with T-cell lymphoma treated with < or = 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.

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.