Splenic irradiation in hematologic malignancies and other hematologic disorders--single institution experience

Splenic irradiation has long been known as a palliative treatment modality in patients with various malignant hematologic diseases aiming to ameliorate clinical symptoms of splenomegaly as well as clinical sequels of hypersplenism. It provides considerable effect with low toxicity although exact radiotherapy dose and fractionation schedule are not known. During the 1996-2010 period, eleven patients were treated at our institution with splenic irradiation. They received 16 courses of fractionated radiotherapy. There were six patients with non-Hodgkin's lymphoma, four with chronic lymphocytic leukemia, and one patient with myelofibrosis. The median of the dose received was 7 Gy, while the median of dose received per fraction was 1 Gy. Both parallel opposed anterior-posterior fields and tangential fields were used. Due to the clinical target volume shrinkage, the treatment field was reduced in 44% of courses. Of the courses initiated for symptom control, 71% resulted in effective palliation, whereas of the courses started to treat hematologic sequels of hypersplenism 50% produced desirable effects. The most common side effects included thrombocytopenia and anemia. Splenic irradiation provides effective and low-toxic palliation of symptoms but it is much less successful in treating hematologic disorders caused by hypersplenism.