Abstract
11C-methionine (11C-MET) is a new positron emission tomography (PET) tracer for the assessment of disease activity in multiple myeloma (MM) patients, with preliminary data suggesting higher sensitivity and specificity than 18F-fluorodeoxyglucose (18F-FDG). However, the value of tumor burden biomarkers has yet to be investigated. Our goals were to corroborate the superiority of 11C-MET for MM staging and to compare its suitability for the assessment of metabolic tumor burden biomarkers in comparison to 18F-FDG. Twenty-two patients with newly diagnosed, treatment-naïve symptomatic MM who had undergone 11C-MET and 18F-FDG PET/CT were evaluated. Standardized uptake values (SUV) were determined and compared with total metabolic tumor volume (TMTV) for both tracers: total lesion glycolysis (TLG) and total lesion 11C-MET uptake (TLMU). PET-derived values were compared to Revised International Staging System (R-ISS), cytogenetic, and serologic MM markers such as M component, beta 2 microglobulin (B2M), serum free light chains (FLC), albumin, and lactate dehydrogenase (LDH). In 11 patients (50%), 11C-MET detected more focal lesions (FL) than FDG (p < 0.01). SUVmax, SUVmean, SUVpeak, TMTV, and TLMU were also significantly higher in 11C-MET than in 18F-FDG (p < 0.05, respectively). 11C-MET PET biomarkers had a better correlation with tumor burden (bone marrow plasma cell infiltration, M component; p < 0.05 versus p = n.s. respectively). This pilot study suggests that 11C-MET PET/CT is a more sensitive marker for the assessment of myeloma tumor burden than 18F-FDG. Its implications for prognosis evaluation need further investigation.
Highlights
Multiple myeloma (MM) is a malignant disorder of clonal plasma cells (PCs) that represents approximately 10% of hematological malignancies [1]
In 11 C-MET Positron emission tomography (PET)/computed tomography (CT), diffuse bone marrow (BM) infiltration, as a single abnormality, was detected in 6/22 (27.3%) patients, while focal lesions (FL) only were present in 3/22 cases (13.6%), and a combined pattern was detected in
With 18 F-FDG PET/CT, disease was categorized as only diffuse BM in 6/22 (27.3%), FL in 10/22 (45.5%), and a combined pattern in 6/22 (27.3%) patients
Summary
Multiple myeloma (MM) is a malignant disorder of clonal plasma cells (PCs) that represents approximately 10% of hematological malignancies [1]. In combination with computed tomography (CT) and 18 F-fluorodeoxyglucose (18 F-FDG) is a well-established imaging technique in MM. It has proven its value in the assessment of tumor burden and disease activity in MM, with sensitivity and specificity ranging from 80% to 100% [2,3]. It has demonstrated prognostic impact, and the presence of more than three focal lesions (FL), maximum standardized uptake values (SUVmax) higher than 4.2, or the presence of extramedullary disease are, predictors of poor prognosis [4,5]. Patients with high TLG had poor outcome even in the context of molecularly defined low-risk disease, highlighting the additional value of novel markers in the assessment of MM
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
