[Splenic irradiation in myeloid hemopathies: evaluation and toxicity]

Abstract

Purpose: Splenomegaly occurs frequently in patients with myelofibrosis (MF) or chronic myelogenous leukemia (CML), indicating significant splenic metaplasia. Symptomatic radiation therapy can be delivered, but the best irradiation scheme is still unknown. Results of splenic irradiation in patients with myelofibrosis or chronic leukemia were retrospectively analyzed.

Patients and methods: There were 24 patients: 15 presented with MF and 9 with CML. Median irradiation doses were 9.8 and 7.7 Gy, respectively. The hematologic toxicity was moderate (except for platelets in the acute phase of the disease).

Results: No toxicity was observed. Various factors predictive of the response to radiation therapy are described. While high (around 14 Gy) radiation therapy dose appears necessary for MF and should be started before the increase in transfusion need, huge splenomegalies should be excluded in regard to CML. As for other cases, the optimal dose is still unclear, but should probably be high enough, ie, around 10 Gy.

Conclusion: To further study and better understand biological mechanisms underlying response to radiotherapy in patients with MF, prospective radio-chemotherapy phase II trials should be conducted in both CML and MF patients.