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

PRIMARY OBJECTIVES:

I. To evaluate the efficacy of ultra-low dose 4 Gy gastric radiation, measured as complete
gastric response at one year after 4 Gy treatment in patients with marginal zone lymphoma
involving the stomach mucosa-associated lymphoid tissue (MALT).

SECONDARY OBJECTIVES:

I. To evaluate distant recurrence of marginal zone lymphoma at one year. II. To evaluate
toxicity associated with gastric radiation therapy.

EXPLORATORY OBJECTIVES:

I. To determine if microbiome assessment can predict response to ultra-low dose radiation
therapy and evaluate the differences in patient microbiome for patients who respond well and
poorly to low dose radiation.

II. To determine if micro-ribonucleic acid (RNA) assessment can predict response to ultra-low
dose radiation therapy and evaluate the differences in patient microRNA profiles for patients
who respond well and poorly to low dose radiation III. To explore the role of magnetic
resonance imaging (MRI) for staging gastric MALT lymphoma and for predicting response to
ultra-low dose radiation therapy.

OUTLINE:

Patients undergo low-dose radiation therapy over 2 fractions for 2 consecutive days in the
absence of disease progression or unacceptable toxicity. Patients with stable or progressive
disease at 12-16 weeks post-treatment, or persistent disease at 1 year may undergo
higher-dose radiation therapy at the discretion of treating physician.

After completion of study treatment, patients are followed up every 3 months for up to 1
year.

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 prior to treatment

- Patients must undergo colonoscopy prior to treatment to confirm the absence of
additional disease within the gastrointestinal tract

- 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 history of prior radiation to the stomach if re-treatment would exceed
known gastric or surrounding critical structure (e.g., bowel, spinal cord) tolerance

- Patients who are pregnant

- Patients with scleroderma are ineligible

- Patients with compromised renal function or contrast allergies that prevent staging
with contrast-enhanced computed tomography (CT)