Ultra Low-Dose Radiation Therapy in Treating Patients With Stage I-IV Stomach MALT Lymphoma

Inclusion Criteria: * Patients 18 years or older with stage I-IV MALT lymphoma involving the stomach. Other low grade lymphomas including follicular grade I/II and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) are ineligible * Patients must have biopsy-proven disease within the stomach. Patients with clinical and/or radiographic masses will have dimensions noted prior to therapy * Patients must have H. pylori testing which is negative within 6 months prior to treatment * Female patients of childbearing potential must have a negative serum pregnancy test (human chorionic gonadotropin \[hCG\]) within 2 weeks of protocol entry * Planned systemic therapy prior to, during, or after gastric radiation therapy is permitted however the timing of systemic therapy will be recorded and patients will be stratified according to receipt of systemic therapy * Patients must have the ability to give informed consent * Necessary treatment with antibiotics for reasons unrelated to gastric lymphoma is permitted however the timing and nature of the treatment will be recorded Exclusion Criteria: * Patients with aggressive B cell lymphoma histology, including diffuse large B cell lymphoma (DLBCL) and grade 3 follicular lymphoma * Patients with other histologic subtypes of low grade lymphoma (other than MALT) including chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) or follicular lymphoma * Patients with bulky tumors \> 10 cm in any dimension * Patients with a…