Improved Detection of Minimal Residual Disease by 11C-Methionine PET/CT in a Young Patient With Unusual Extramedullary Presentation of Recurrent Multiple Myeloma

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

2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography/computed tomography (FDG PET/CT) has an established clinical value in the diagnosis and initial staging of multiple myeloma (MM). In the last ten years, a vast body of literature has shown that this tool can also be of high relevance for monitoring therapy responses, making it the recommended imaging approach in this field. Starting from the strengths and weaknesses of radiological imaging in MM, the present review aims to analyze FDG PET/CT’s current clinical value focusing on therapy response assessment and objective interpretation criteria for therapy monitoring. Given the potential occurrence of patients with MM showing non-FDG-avid bone disease, new opportunities can be provided by non-FDG PET tracers. Accordingly, the potential role of non-FDG PET tracers in this setting has also been discussed.

Dural MALT Lymphoma Detected by 11C-Methionine PET/CT

A 53-year-old man had a diagnosis of mucosa-associated lymphoid tissue lymphomas of the dura in the left tentorium. The patient underwent whole-body F-FDG PET/CT and C-methionine PET/CT in order to complete the staging of dural mucosa-associated lymphoid tissue lymphoma. C-methionine uptake was detected in multiple meningeal sites, including left tentorium, with no significant FDG uptake in the same regions.

11C-Methionine-Avid Plasmablastic Lymphoma

A 73-year-old woman had a diagnosis of a plasmablastic lymphoma by the excision of the right parotid gland. Two years after the diagnosis, the patient underwent a whole-body C-methionine PET/CT in order to evaluate the amino acid avidity of a scalp metastasis and for plasmablastic lymphoma restaging. C-methionine uptake was detected in the scalp, in several bone sites, and in the cricoid cartilage. Plasmablastic lymphoma is a subtype of B-cell lymphoma with an aggressive behavior and a poor prognosis. C-methionine appears to be a promising tracer for paraprotein-producing neoplasms.