18F–FDG PET/CT in solitary plasmacytoma: metabolic behavior and progression to multiple myeloma
Solitary plasmacytoma (SP) is a rare plasma-cell neoplasm, which can develop both in skeletal and/or soft tissue and frequently progresses to multiple myeloma (MM). Our aim was to study the metabolic behavior of SP and the role of 18F–FDG-PET/CT in predicting progression to MM.
Materials and methods
Sixty-two patients with SP who underwent 18F–FDG-PET/CT before any treatment were included. PET images were qualitatively and semiquantitatively analyzed by measuring the maximum standardized uptake value body weight (SUVbw), lean body mass (SUVlbm), body surface area (SUVbsa), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and compared with age, sex, site of primary disease, and tumor size.
Fifty-one patients had positive 18F–FDG-PET/CT (average SUVbw was 8.3 ± 4.7; SUVlbm 5.8 ± 2.6; SUVbsa 2 ± 1; MTV 45.4 ± 37; TLG 227 ± 114); the remaining 11 were not 18F–FDG-avid. Tumor size was significantly higher in patients avid lesions compared to FDG not avid; no other features are associated with FDG-avidity. Progression to MM occurred in 29 patients with an average of 18.3 months; MM was more likely to develop in patients with bone plasmacytoma and in patients with 18F–FDG avid lesion. Time to transformation in MM (TTMM) was significantly shorter in patients with osseous SP, in 18F–FDG avid lesion, for SUVlbm > 5.2 and SUVbsa > 1.7.
18F–FDG pathological uptake in SP occurred in most cases, being independently associated with tumor size. PET/CT seemed to be correlated to a higher risk of transformation in MM, in particular for 18F–FDG avid plasmacytoma and SBP. Among semiquantitative features, SUVlbm > 5.2 and SUVbsa > 1.7 were significantly correlated with TTMM.
KeywordsSolitary plasmacytoma Solitary bone plasmacytoma Extramedullary plasmacytoma 18F–FDG pet/ct
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study formal consent is not required.
Informed consent was obtained from all individual participant included in the study.
- 6.Dimopoulos MA, Hamilos G. Solitary bone plasmacytoma and extramedullary plasmacytoma. Curr Treat Options Oncol. 2002;3:255–9.Google Scholar
- 20.Cavo M, Terpos E, Nanni C, Moreau P, Lentzsch S, Zweegman S, et al. Role of 18F-FDG PET/CT in the diagnosis and management of multiple myeloma and other plasma cell disorders: a consensus statement by the international myeloma working group. Lancet Oncol. 2017;18:e206–17.CrossRefPubMedGoogle Scholar
- 21.Chantry A, Kazmi M, Barrington S, Goh V, Mulholland N, Streetly M, et al. Guidelines for the use of imaging in the management of patients with myeloma. Br J Hematol. 2017; https://doi.org/10.1111/bjh.14827.