Low dose palliative radiotherapy for splenomegaly in hematologic disorders.

Splenomegaly (SM) is a common complication in hematologic disorders often associated with hypersplenism, and may cause pain, epigastric discomfort and variable systemic effects due to cytopenias. We retrospectively evaluated the results of palliative splenic irradiation (PSI) in terms of symptomatic relief in patients with hematologic disorders. In 1998-2006, 32 patients with hematologic disorders (median age 57) received 52 courses of PSI for SM. Twenty-one patients (66%) were diagnosed with myeloproliferative disorders (MPD), five patients (16%) had malignant lymphoma (ML), five patients (16%) had chronic lymphocytic leukemia (CLL) and one patient (3%) had hairy cell leukemia. Splenomegaly was accompanied by pain, anemia, thrombocytopenia and cachexia. Radiation therapy to the entire spleen was delivered by two parallel opposed fields using 0.5 Gy daily fractions given 5 days per week to a total dose of 6-10 Gy. PSI resulted in splenic size reduction in 78.8%, improvement of anemia in 75% and improvement of thrombocytopenia in 63.5% of PSI courses. The median survival (MS) of patients with MPD, CLL and ML was 45, 10 and 5 months, respectively. The MS of responders to PSI versus non-responders was 45 and 16 months, respectively (hazard ratio 0.17; p = 0.03; 95% confidence interval 0.035-0.84). In our hands, low dose PSI provided effective palliation for patients with hematologic disorders with SM. Splenic re-irradiation was feasible without excessive toxicity.