Special delivery: getting radiation to the target in diffuse large B-cell lymphoma

Abstract

Th e term early ” “ or “ limited ” stage diff use large B-cell lym phoma (DLBCL) embraces a diverse group of clinical presentations, broadly divisible into favorable and unfavorable categories. A highly selected group of patients with non-bulky, stage I nodal disease, and an International Prognostic Index (IPI) score of zero, are considered to have favorable disease. Such patients can anticipate a cure rate of approximately 90% with either six cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) or three cycles of R-CHOP plus involved fi eld radiotherapy [1,2]. It is unknown which of these treatment strategies off ers a higher freedom from progression rate, but any diff erence is likely to be too small to resolve in a feasible randomized trial. Research in this population is oriented toward defi ning minimal eff ective therapy, paralleling the evolution of management for favora ble early stage Hodgkin lymphoma. Unfavorable early stage DLBCL is much more heteroge-neous. Disease may be unfavorable by virtue of “stage-modi- fi ed ” IPI 1 (age , lactate dehydrogenase [LDH], performance status, stage I versus II), bulky disease (variously defi ned), special extranodal sites of origin, such as the testis or central nervous system, and an incomplete metabolic response on interim positron emission tomography (PET) scanning [3]. Th ese risk factors predict a treatment failure rate of at least 25% with R-CHOP alone, and defi ne a patient population suitable for treatment intensifi cation or consolidation. In the routine management of unfavorable early stage DLBCL, alternatives to R-CHOP alone include the use of more inten-sive chemotherapy regimens and/or consolidation with ionizing radiation, traditionally in the form of external beam radiotherapy (EBRT) [4,5]. In this issue of