RESUMEN
PURPOSE: The primary objective was to determine in our department the progression-free survival rate of patients with solitary bone plasmocytoma and secondarily to evaluate its diagnostic, therapeutic and evolutionary aspects. PATIENTS AND METHODS: This is a retrospective review of 12 patients monitored and treated in the radiotherapy department of the Mohammed-V military medical teaching hospital in Rabat for a solitary bone plasmocytoma between January 2012 and December 2018. The average age of our patients were 53.8 years old (range: 31-72 years old). Pain was the most common telltale sign. The site of the lesions was spinal in four cases, iliac in four cases, mandibular, ribal, humeral and at the level of the astragalus in one case respectively. All patients received radiotherapy. This irradiation was delivered alone in 60% of cases or associated with surgery in 40% of cases. The average dose of radiotherapy was 47.3Gy (range: 45 to 50.4Gy) and this was delivered by a modulated volumetric arc therapy technique in ten patients and conformal tridimensional radiotherapy in two patients. RESULTS: Local control, defined by stability or radiological regression, was obtained in ten patients and four patients progressed to multiple myeloma, two of whom died. The average duration of follow-up was 51 months. CONCLUSION: Radiation therapy is the standard treatment for solitary bone plasmocytoma. It ensures good local control in 90% of cases. The prognosis is affected by progression to multiple myeloma, which justifies rigorous monitoring after treatment and suggests a reflection on the exact place of chemotherapy.