-Author name in bold denotes the presenting author
-Asterisk * with author name denotes a Non-ASH member
Clinically Relevant Abstract denotes an abstract that is clinically relevant.

PhD Trainee denotes that this is a recommended PHD Trainee Session.

Ticketed Session denotes that this is a ticketed session.

3190 11c-Methionine PET/CT in Assessment of Multiple Myeloma Patients: Comparison to 18f-FDG PET/CT and Prognostic Value Evaluation

Program: Oral and Poster Abstracts
Session: 652. Multiple Myeloma and Plasma Cell Dyscrasias: Clinical and Epidemiological: Poster II
Hematology Disease Topics & Pathways:
Plasma Cell Disorders, Diseases, Lymphoid Malignancies, Technology and Procedures, Human, Study Population, imaging
Sunday, December 11, 2022, 6:00 PM-8:00 PM

María Isabel Morales-Lozano1*, María Marcos Jubilar2*, Lidia Sancho Rodriguez1*, Ana Alfonso-Pierola, MD, PhD3*, Jorge M Nuñez-Cordoba4*, Elena Prieto Azcárate1*, Luis Esteban Tamariz-Amador, MD2*, Juan J Rosales Castillo1*, Maria Luisa Palacios-Berraquero, MD2*, Fernando Guillen Valderrama1*, Andrea Manubens Guarch2*, Angela Bronte Viedma1*, Sofía Huerga Domínguez2*, Victoria Betech Antar1*, Maria Panizo Inogés, MBBS5*, Felipe Prosper, MD2*, Ramon Lecumberri, MD, PhD2*, Jesús San-Miguel, MD, PhD6, Paula Rodríguez Otero, MD, PhD2* and María José García Velloso1*

1Department of Nuclear Medicine, Clínica Universidad de Navarra, Pamplona, Spain
2Department of Hematology, Clínica Universidad de Navarra, Pamplona, Spain
3Department of Hematology, Clinica Universidad de Navarra, Navarra, Spain
4Research Support Service, Central Clinical Trials Unit, Clínica Universidad de Navarra, Pamplona, Spain
5Department of Hematology, Clinica Universidad De Navarra, PAMPLONA, AL, ESP
6Clinica Universitaria de Navarra, Navarra, Spain

Multiple myeloma (MM) is the second most common hematological malignancy and remains incurable despite therapeutic advances. 18F-FDG (FDG) PET/CT is a relevant tool in MM for staging and it is the reference imaging technique for treatment evaluation. However, it has limitations, and investigation of other PET tracers is required. Preliminary results with L-methyl-[11C]- methionine (MET), suggest higher sensitivity than FDG. This study aimed to compare the diagnostic accuracy and prognostic value of FDG and MET in MM patients.

Methods: Fifty-two consecutive patients with MM were prospectively simultaneously evaluated by FDG and MET PET/CT. Bone marrow (BM) uptake patterns and the detection of focal lesions (FL) and extramedullary disease (EMD) were compared. Furthermore, FDG PET parameters with known MM prognostic value were explored for both tracers, as well as total metabolic tumor volume (TMTV), total lesion glycolysis (TLG), and total lesion MET uptake (TLMU).

Results: Median patient age was 61 years (range, 37-83 years), 54% were male, 13% of them were in stage ISS (International Staging System) III, and 31% had high-risk cytogenetics. The population include 8 smoldering MM (SMM), 18 newly diagnosed MM (NDMM) and 26 relapse/refractory patients (RRMM).

In six out the total 52 patients (11%) FDG did not detect active disease while they showed to be positive by MET. It should be noted that 4 out of these 6 patients were SMM. Additionally, MET identified higher number of FL than FDG in more than half of the patients (63%). Moreover, the median values for TMTV and total lesion uptake (TLG/TLMU) were higher upon using MET.

None of the SMM patients has progressed so far. Therefore, the prognostic impact of basal PET cannot be investigated in this cohort. Only 4 out of the 18 NDMM patients have progressed so far. The small number of events in the cohort of NDMM patients precludes a sound prognostic analysis. Nevertheless, progressive patients were associated with a larger number of FL, tumor volume and EMD assessed by both, FDG or MET.

In the RRMM patient cohort, 13 out the total 26 patients analyzed by PET have already progress. Upon using FDG the median number of FL (particularly more than 10), as well as the median values of TLG and TMTV were significantly higher in the group of progressive patients. Almost identical results were observed upon using MET.

Conclusion: This study confirmed the diagnostic and prognostic value of FDG in MM; in addition it highlight that MET although it has higher sensitivity than FDG PET/CT for detection of myeloma lesions, including FL, their optimal cut-off values need to be confirmed in larger series of patients. Finally, we show for the first time, the prognostic value of TMTV and TLMU in the imaging evaluation of MM patients.

Disclosures: San-Miguel: Abbvie, Amgen, BMS, Celgene, GSK, Haemalogix, Janssen-Cilag, Karyopharm, MSD, Novartis, Takeda, Regeneron, Roche, Sanofi, and SecuraBio: Consultancy, Other: Advisory Board. Rodríguez Otero: Regeneron: Speakers Bureau; BMS-Celgene: Speakers Bureau; Amgen: Speakers Bureau; GSK: Consultancy, Speakers Bureau; Pfizer: Consultancy; Sanofi: Consultancy, Speakers Bureau; BMS: Consultancy; Janssen: Consultancy, Speakers Bureau.

*signifies non-member of ASH