[Value of ¹⁸F-FDG PET/CT Imaging in Secondary Extramedullary Infiltration of Multiple Myeloma]

To investigate the characteristics of ¹⁸F-FDG PET/CT images of multiple myeloma secondary extramedullary infiltration in order to improve recognition.

Twenty-one patients with multiple myeloma secondary extramedullary infiltration confirmed by pathology or follow-up from January 2012 to October 2020 in the First Affiliated Hospital of University of Science and Technology of China were retrospectively analyzed. All the patients underwent ¹⁸F-FDG PET/CT imaging before treatment, and the PET/CT characteristics of extramedullary infiltration and bone marrow were analyzed.

Twenty-one patients included 12 males and 9 females, aged from 41 to 77 years old, with an average of 58.3±10.0; 9 cases of extramedullary infiltration involving lymph nodes; lung, stomach, spleen, and kidney were involved respectively in 2 cases; retroperitoneal, right auricle, subcutaneous nodule, and spinal meninges involvement were reported in each one case respectively. The maximum SUVmax value of extra-medullary lesions was 21.2, the minimum value was 2.1, and mean was 7.7±5.3. The maximum SUVmax value of bone marrow was 33.5, the minimum was 2.4, and mean was 6.6±3.6. There was no statistically significant difference in SUVmax value between extra-medullary lesions and bone marrow (Z=-1.195, P=0.232).

¹⁸F-FDG PET/CT not only has a good diagnostic value for multiple myeloma, but also a good evaluation value for secondary extramedullary infiltration, which provides reference for clinical treatment and prognosis.