Non‐Hodgkin's lymphomas. V. Results of radiotherapy

Four hundred and five patients with non‐Hodgkin's lymphomas, referred between 1960 and 1971, were carefully evaluated for extent of disease prior to therapy. Tumors were histologically classified according to the criteria of Rappaport et al and patients staged by the criteria of the Ann Arbor Conference. Of 234 patients, Stages I‐IIIE, 215 received initial radiotherapy, 91% with a curative intent. Follow‐up time ranged from 1–12 years. Calculations were made of actuarial survival and disease‐free‐survival for each group of patients according to initial stage, histologic type of lymphoma, and type of radiotherapy. Patients with diffuse histiocytic (DH) lymphoma exhibited a 65% probability of tumor relapse during the first year of follow‐up in contrast to the 19% probability for comparably staged patients with nodular mixed histiocytic‐lymphocytic (NM) and nodular lymphocytic poorly differentiated (NLPD) lymphomas. Patients with diffuse mixed (DM), diffuse lymphocytic (DLPD), and nodular histiocytic (NH) lymphomas exhibited an intermediate risk of relapse during the first year (39‐45%). Patients with NM and NLPD manifested a pattern of continued late relapse whereas those with DH lymphoma seldom experienced new evidence of tumor after the first year of disease‐free observation. Patients with localized extralymphatic lymphoma (IE, IIE, IIIE) demonstrated patterns of clinical behavior following radiotherapy similar to those observed in patients whose lymphomas were confined to lymphatic tissue (I, II, III). The data offer strong support for the continued use of the Rappaport et al. histologic classification and the Ann Arbor clinical staging system in the radiotherapeutic managemement of patients with the non‐Hodgkin's lymphomas.