Assessing Risk Of Atherosclerosis In Smoldering Multiple Myeloma Patients By Means Of F-18-Sodium Fluoride With Global Assessment

635 Background: Smoldering multiple myeloma (SMM) is a pre-cancerous form of multiple myeloma (MM) and is characterized by the presence of an abnormal protein in the blood produced by plasma cells and/or increase in plasma cells in bone marrow, but it does not cause symptoms of MM. About half of those diagnosed with SMM, however, will develop MM within 5 years. Based on our knowledge, no previous study, neither clinically nor at the molecular level, evaluated the risk of cardiovascular disease in SMM patients. However, since MM is the third most common form of malignancy associated with cardiovascular diseases and due to the high risk of progression of SMM to MM, it can be expected that SMM patients would be at higher risk of cardiovascular disease in comparison to a normal healthy population. Aim: The main aim of this study was to assess 18F-sodium fluoride (NaF) uptake in the thoracic aorta and whole heart, as an early indicator of atherosclerosis, in SMM patients and compare it to that of an age- and sex-matched healthy control (HC) group. We also aimed to assess the correlation between thoracic aorta calcification (TAC) with whole-heart calcification in SMM patients.\n Methods: Nine SMM patients were collected from a prospective study (FULIMA), and 9 HC subjects were collected from another prospective study (CAMONA). OsiriX software was used to assess NaF uptake in three parts of the aorta (AA: ascending aorta, AR: aortic arch, DA: descending aorta) and whole-heart. The global mean standardized uptake value (SUVmean) was derived as the sum of the product of each slice area and SUVmean divided by the sum of those slice areas. For normalization, target-to-background ratio (TBR) was calculated.\n Results: There was a significant difference between the NaF uptake in the thoracic aorta of SMM patients and HC subjects [AA (SMM= 1.73± 0.16, HC= 1.17± 0.01, p= 0.002), AR (SMM= 1.57± 0.12, HC= 1.20± 0.01, p= 0.01) and DA (SMM= 1.85± 0.28, HC= 1.34± 0.04, p= 0.02)]. Also, the difference in the whole-heart NaF uptake between two groups was significant (SMM= 1.27± 0.20, HC= 0.97± 0.02, p= 0.001). A significant correlation was found between TAC and whole-heart measurements (Pearson correlation: AA= 0.93, AR= 0.96 and DA= 0.95; p-values\u003c 0.001). Conclusions: For the first time, this study focused on the risk of atherosclerosis in a pre-cancerous disorder, SMM, by means of NaF using a global assessment approach. Our results showed that the uptake of NaF in the thoracic aorta and whole-heart of SMM patients was higher than in a matched control group. This seems to support the feasibility of using NaF-PET/CT for evaluating calcification in the mentioned regions, as an early indicator of atherosclerosis, in SMM patients. There was also a significant correlation between TAC and whole-heart NaF uptake in SMM. This is in accordance with previous studies suggesting thoracic aorta calcification can be considered for evaluation of atherosclerosis. Further studies with larger sample including clinical outcome data are warranted.