Splenic radiation for corticosteroid-resistant immune thrombocytopenia

To determine the role of splenic radiation as a treatment for immune thrombocytopenia.

Retrospective analysis of an open, nonrandomized investigation.

A regional cancer center, referred care, and primary care settings.

Eleven older patients with idiopathic thrombocytopenic purpura (ITP) and 8 patients with secondary immune thrombocytopenia refractory to corticosteroid treatment for whom surgery would have posed a high risk.

A short course (1 to 6 weeks) of radiation therapy to the spleen (total dose, 75 to 1370 cGy) with or without concurrent and postradiation corticosteroid administration.

Efficacy was assessed by measuring any increase in the platelet count and by monitoring the duration of response and side effects.

Of 11 patients with ITP, 8 patients responded. Three patients had a sustained (greater than 52 weeks) increase in the platelet count to safe levels after therapy was discontinued. An additional patient had a sustained response but required intermittent, low-dose corticosteroids. Four other patients had increases in their platelet counts that lasted from 8 to 25 weeks. Two of the eight patients without ITP had a positive response, whereas four did not respond, and two were not evaluable. Patients had no adverse reactions to the radiation treatment.

Splenic radiation can be a safe and effective method to raise the platelet count in older patients with ITP that is refractory to corticosteroids and in whom the risks associated with splenectomy are high.