Involved Field Radiotherapy for Non-gastric Marginal Zone Lymphoma

Aims of the study : * To conduct the first multicentre prospective trial of radiotherapy (RT) in stage I-II Marginal Zone Lymphoma (MZL) * To prospectively identify causal factors for MZL, including infection and inflammatory disease This study will be the first large trial of any form of therapy for stage I-II, non-gastric marginal zone lymphoma. There is an enormous deficit in the literature with respect to this fascinating but relatively recently-recognised entity. MZL is commonly associated with underlying inflammatory or infective disorders and it is clear, at least in some cases with infection by organisms called Helicobacter pylori and Chlamydia psitacci, that the inflammatory condition can actually cause the lymphoma. The role of H. pylori infection has not been well studied in non gastric MZL in large prospective studies, despite anecdotal reports of regression of non gastric MZL after H. pylori eradication. There have been reports of responses to doxycycline (antibacterial) therapy in patients with evidence of chlamydial infection (C. psitacci) in MZL of the tissues around the eye. This association has not been well studied in any large prospective study and no long-term data for doxycycline therapy exist. Management of stage I-II MZL is variable and often ad-hoc in Australia, despite significant retrospective evidence to support radiotherapy (RT) as the curative treatment modality of choice. In this TROG/ALLG joint study, 100 patients will be recruited over 5 years. All patients will undergo breath tests or endoscopy to detect H. pylori infection. Ocular MZL specimens will be sent to Italy to test for C. psitacci. Patients will receive highly standardised treatment with RT. This study will definitively document the efficacy and safety of RT in stage I and II non-gastric MZL and will include patients with stage IV disease limited to paired-organs, as this disease shows a tendency to home in exclusively on particular organs, such as salivary glands.