18F-FDG and 11C-Methionine PET/CT in Newly Diagnosed Multiple Myeloma Patients: Comparison of Volume-Based PET Biomarkers

Abstract

11 C-methionine ( 11 C-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 18 F-fluorodeoxyglucose ( 18 F-FDG). However, the value of tumor burden biomarkers has yet to be investigated. Our goals were to corroborate the superiority of 11 C-MET for MM staging and to compare its suitability for the assessment of metabolic tumor burden biomarkers in comparison to 18 F-FDG. Twenty-two patients with newly diagnosed, treatment-naïve symptomatic MM who had undergone 11 C-MET and 18 F-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 11 C-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%), 11 C-MET detected more focal lesions (FL) than FDG (p < 0.01). SUVmax, SUVmean, SUVpeak, TMTV, and TLMU were also significantly higher in 11 C-MET than in 18 F-FDG (p < 0.05, respectively). 11 C-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 11 C-MET PET/CT is a more sensitive marker for the assessment of myeloma tumor burden than 18 F-FDG. Its implications for prognosis evaluation need further investigation.

FDG-PET/CT, a Promising Exam for Detecting High-Risk Myeloma Patients?

“…Thus, they demonstrated that MET uptake was correlated with bone marrow involvement, β2-microglobulin and free light chain levels, and appears to be a more accurate market of tumor burden compared to 18 FDG [43]. Another recent study confirmed the excellent sensitivity of MET for the assessment of MM tumor burden compared to 18 FDG [44]. Nevertheless, the prognostic value of this tracer need further investigation particularly in comparison with 18 FDG, which is currently the strongest marker in this pathology.…”

Positron Emission Tomography (PET) Imaging of Multiple Myeloma in a Post-Treatment Setting

“…MET is able to reflect the synthetic protein turnover by malignant cells and its uptake is not influenced by non-disease related determinants of bone marrow tracer uptakes such as anemia or systemic inflammation. This feature results in a good sensitivity concerning FDG in describing the degree of bone infiltration in the staging phase [ 61 , 62 , 63 ], even when low monoclonal protein-producing myelomas such as IgD, IgE and non-secretory types are studied [ 64 ]. The higher adherence of MET uptake (compared with FDG uptake) to the proliferative activity of MM resulted also in a higher sensitivity in the detection of minimal residual disease in a young patient with an unusual extramedullary (vulvar) presentation of recurrent MM [ 65 ].…”

The role of positron emission tomography in different types of malignant lymphomas: the results of 2020

“…В 2020 г. M. Morales-Lozano и соавт. [13] представили результаты исследований 22 пациентов с впервые выявленной ММ, до начала лечения, которым выполняли ПЭТ как с 18F-ФДГ, так и с 11 C-Мет. Предварительные результаты показали преимущество 11 C-Мет в определении распространения опухолевого поражения в сравнении с 18F-ФДГ.…”