The treatment of solitary plasmacytoma of bone and extramedullary plasmacytoma.

Eleven patients with solitary plasmacytoma of bone (SPB) and six patients with extramedullary plasmacytoma (EMP) were treated at the UCLA Center for the Health Sciences. Primary treatment in 14 of 17 patients was with radiation, while three patients were irradiated for recurrent disease. Eleven patients with SPB were irradiated with dose of 32-55 Gy, with 10 of 11 patients receiving doses of 40-55 Gy. Local control was achieved in 10 of 11 patients with SPB. One patient died with metastatic disease with unknown local status. Six patients with EMP were irradiated with doses of 38-56 Gy. Of these patients, two were locally controlled; one patient failed locally; one patient died during treatment; one patient died with local disease at 85 months after multiple resections, chemotherapy, and two courses of irradiation; and one patient was lost to follow-up. Progression to multiple myeloma was seen in 5 of 11 patients with SPB and in none of six patients with EMP. For patients with SPB, we recommend treating the entire bone to 40 Gy, with a boost when feasible. Patients with EMP receive the same dose, including the lymph nodes in tumors at high risk for spread. Radical surgical resections appear to be unwarranted.