Solitary plasmacytoma (SP) is characterized by a localized mass of clonal plasma cells with no or minimal bone marrow plasmacytosis. It can present either as EMP or SBP. Radiotherapy is the first-line treatment with high response rate. However, 65-84% SBP patients and 25-35% EMP patients progress at 10 years. We aimed to investigate whether adjuvant bortezomib based chemotherapy with radiotherapy could prolong event-free survival in treatment-naive SP patients compared to that with radiotherapy alone.

Inclusion Criteria:

• treatment-naïve SP.

Exclusion Criteria:

• Not appropriate for radiotherapy.
• ECOG > 2.
• Co-morbidity of uncontrolled infection.
• Co-morbidity of other active malignancy.
• Patients in pregnancy or lactation.
• Prior or concurrent pulmonary embolism.
• Patients not able to tolerate thrombosis prophylaxis, bortezomib, lenalidomide or dexamethasone.
• Seropositive for human immunodeficiency virus, seropositive for hepatitis C, or HBV-DNA > 1000 copies/mL.
• Myocardial infarction, NYHA Class III or IV heart failure, uncontrolled angina, severe uncontrolled arrhythmias within 6 months prior to enrollment.
• Grade 2 or higher neuropathy according to National Cancer Institute Common Terminology Criteria for Adverse Events.
• Neutrophil <1×10E9/L，hemoglobin < 8g/dL，or platelet < 75×10E9/L.
• Severely compromised hepatic or renal function: ALT or AST > 3 × ULN, total bilirubin > 1.5 × ULN，or eGFR < 40mL/min.