Diffuse large B cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma in Korea. Although there is standard therapy, which is called 'R-CHOP', many obstacles to use aggressive cytotoxic chemotherapeutic agents such as old age, poor performance status, refractoriness, and relapsed disease still remains. So we investigate the efficacy of radioimmunotherapy using 131I-rituximab in refractory or relapsed patients with DLBCL.

Inclusion Criteria:

• Histologically confirmed diffuse large B cell lymphoma Elderly (>65 years) or medically ineligible to standard cytotoxic chemotherapy due to poor performance status, or relapsed or refractory patients Eastern Cooperative Oncology Group performance status ≤ 2, age≥ 20 years Relapsed or refractory after autologous hematopoietic stem cell transplantation (auto-HSCT) in young patients with good performance status and indicated to high dose chemotherapy and auto-HSCT More than one measurable lesion
• More than 2cm sized lesion in conventional CT scan,
• More than 1cm sized lesion in spiral CT or contrast-enhanced PET/CT Adequate renal function (serum creatinine ≤ 2.0 mg/dl or Ccr ≥ 60 ml/min) Adequate hepatic function (serum bilirubin ≤ 2.0 mg/dl , AST/ALT ≤ 3 upper normal limit) Adequate bone marrow reservoir (ANC ≥1,500/㎕, platelet count≥ 75,000/㎕) patient who agree the purpose and intention of this clinical trial

Exclusion Criteria:

• recent (<5 years) history of other malignancy or unrecovered from the disease (appropriately treated skin cancer and uterine cervix carcinoma in situ are excluded)

  • hemodynamically unstable due to the recent (<12 months) history of severe heart disease such as myocardial infarction
  • acute complications of severe lung or metabolic disease
  • Combined severe neurological or psychiatric disease Unrecovered from infection or other medical disease Recent (<30 days) history of enrollment of other clinical trial Pregnant or breast-feeding woman women of childbearing potential and men not employing adequate contraception at least for 1 year Previous history drug allergy to the content of 131I-rituximab Infection(sepsis, pneumonia, viral infection, etc) (inactivated hepatitis B carrier can be enrolled) Young patient with good performance status indicated to autologous hematopoietic stem cell transplantation irrespective of the failure of 1st line chemotherapy