Radiotherapy for gastrointestinal lymphomas: indications and techniques

Abstract

Gastrointestinal lymphomas are almost exclusively of a non-Hodgkin's type. The Western form is characterized by a higher incidence of stomach location (50%), a MALT type (mucosa associated lymphoid tissue) (40%), a B-cell type (90%), and a high grade (55%). Chronic infection with Helicobacter pylori is an important risk factor. Mediterranean lymphomas form a particular clinical and pathological entity with diffuse involvement of the small bowel and are frequently being associated with a chronic malabsorption disorder. Eradication of Helicobacter pylori in early gastric lymphomas, and the use of tetracyclines in early Mediterranean lymphomas, have been shown to induce durable remissions. For more advanced gastric lymphomas, treatment usually consists of anthracyclin-based chemotherapy followed by involved field radiotherapy. Surgery is usually reserved for complications such as perforation or bleeding, or in some selected cases for salvage after failure of non-surgical therapy. For intestinal lymphomas, surgical resection whenever feasible, followed by anthracyclin-based chemotherapy is the most common treatment. Radiotherapy is usually reserved for consolidation in some clinical situations. The most commonly found prognostic factors are stage, grade, and tumor bulk. Treatment results vary with the presence of adverse prognostic factors and the used treatment combination. In general, patients with favorable disease receiving combined therapy have a 5-year relapse free survival (RFS) approaching 90%, whereas those with unfavorable disease have a RFS of 40-50%.