Sequential half-body irradiation as salvage therapy in chemotherapy-resistant multiple myeloma

Fifteen patients with a median age of 58 years, having multiple myeloma resistant to conventional combinations of cytotoxic drugs, received sequential half-body irradiation as salvage therapy. Response was obtained in 53% (n = 8: group 1); this was objective in 40% (n = 6), being defined as 50% or greater reduction in paraprotein, clearance of light chains from the urine, or an unequivocal decrease in tumor bulk on an adequate marrow trephine biopsy; a further 13% (n = 2) just failed to meet these criteria but nevertheless had excellent subjective response. Median survival was 24 months. No objective or subjective improvement occurred in 47% (n = 7: group 2); median transient survival was 4 months. Short-term toxicity was limited to transient nausea in 30% (n = 5) and protracted pancytopenia in about one-half of the patients (n = 7), who remain dependent on intermittent RBC transfusions. Morbidity is only moderate, and the response rate of 53% in refractory patients suggests that sequential half-body irradiation has a definite place in managing patients with end-stage disseminated myelomatosis.