Radiation Therapy Alone for the Treatment of Stage 1 and 2 Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma

Inclusion Criteria: * Patients with newly diagnosed stage 1 and 2 MALT lymphoma are eligible for this study * Patients with Helicobacter (H.) pylori positive gastric MALT lymphoma are recommended to have treatments with antibiotics prior to enrollment to this protocol * Patients who failed other treatment modalities (e.g. chemotherapy, antibiotics therapy etc) are also eligible as far as they never had stage 3 or 4 disease during the course of the disease or disease progression to the opposite side of the diaphragm (as the time course of the response to antibiotic therapy can be very variable among patients, sometimes requiring more than one year for complete response, failure to antibiotic therapy can be very variable among patients, sometimes requiring more than one year for complete response, failure to antibiotic treatment will be defined as no response or progression of the disease documented by endoscopy and biopsy) * Patients who have had stage 4 diseases due to bilateral parotid gland or ocular/ocular adnexal involvement or due to multiple sites within Waldeyer's ring will still be eligible Exclusion Criteria: * Patients who had previous radiation dose to the site of the current primary disease which would lead to violation of known radiation tolerance limit of that particular site if treated again * Patients with MALT lymphoma of the skin whose lesions are separated by more than 5 cm will be ineligible * Previous or concurrent malignancy in any form would not be an exclusion criterion. However, patients who receive chemotherapy for concurrent malignancy will be excluded from statistical analysis * Low blood cell counts would not be exclusion criteria as far as the patient is willing to accept supportive measures such as transfusions, filgrastim and epoetin