Radiotherapy Alone is Associated with Improved Outcomes Over Surgery in the Management of Solitary Plasmacytoma.

Background: A moderate dose of radiation is the recommended treatment for solitary plasmacytoma (SP), but there is controversy over the role of surgery. Our study aimed at comparing different treatment modalities in the management of SP.

Materials And Methods: Data from 38 consecutive patients with solitary plasmacytoma, including 16 with bone plasmacytoma and 22 with extramedullary plasmacytoma, were retrospectively reviewed. 15 patients received radiotherapy alone; 11 received surgery alone, and 12 received both. The median radiation dose was 50Gy. All operations were performed as radical resections. Local progression-free survival (LPFS), multiple myeloma-free survival (MMFS), progression-free survival (PFS) and overall survival (OS) were calculated and outcomes of different therapies were compared.

Results: The median follow-up time was 55 months. 5-year LPFS, MMFS, PFS and OS were 87.0%, 80.9%, 69.8% and 87.4%, respectively. Univariate analysis revealed, compared with surgery alone, radiotherapy alone was associated with significantly higher 5-year LPFS (100% vs 69.3%, p=0.016), MMFS (100% vs 51.4%, p=0.006), PFS (100% vs 33.7%, p=0.0004) and OS (100% vs 70%, p=0.041).

Conclusions: Radiotherapy alone can be considered as a more effective treatment for SP over surgery. Whether a combination of radiotherapy and surgery improves outcomes requires further study.