fluorocholine and Multiple-Myeloma

A man experienced pain in the right hemithorax 6 months after a first-line therapy for multiple myeloma (MM). FDG PET/CT showed a large extramedullary extent in the right hemithorax, which was biopsy proven. During the second-line treatment, FDG PET/CT showed no response as well as a suspected myocardium spread, a rare extramedullary location in MM. F-Fluorocholine PET/CT and then MRI confirmed myocardium lesions. This case confirms that F-fluorocholine PET/CT is able to detect MM recurrence and may be used to complete FDG PET/CT in difficult cases such as suspicion of cardiac MM.

Topics: Biopsy; Choline; Fluorodeoxyglucose F18; Heart; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Multiple Myeloma; Positron Emission Tomography Computed Tomography

Hybrid positron emission tomography/computed tomography (PET/CT) has now become available, as well as whole-body, low-dose multidetector row computed tomography (MDCT) or magnetic resonance imaging (MRI). The radioactive glucose analogue 18F-fluorodeoxyglucose (FDG) is the most widely used tracer but has a relatively low sensitivity in detecting multiple myeloma (MM). We compared FDG with a more recent metabolic tracer, 18F-fluorocholine (FCH), for the detection of MM lesions at time of disease relapse or progression.. We analyzed the results of FDG and FCH imaging in 21 MM patients undergoing PET/CT for suspected relapsing or progressive MM. For each patient and each tracer, an on-site reader and a masked reader independently determined the number of intraosseous and extraosseous foci of tracer and the intensity of uptake as measured by their SUVmax and the corresponding target/non-target ratio (T/NT).. In the skeleton of 21 patients, no foci were found for two cases, uncountable foci were observed in four patients, including some mismatched FCH/FDG foci. In the 15 patients with countable bone foci, the on-site reader detected 72 FDG foci vs. 127 FCH foci (+76 %), whereas the masked reader detected 69 FDG foci vs. 121 FCH foci (+75 %), both differences being significant. Interobserver agreement on the total number of bone foci was very high, with a kappa coefficient of 0.81 for FDG and 0.89 for FCH. Measurement of uptake in the matched foci that took up both tracers revealed a significantly higher median SUVmax and T/NT for FCH vs. FDG. Almost all unmatched foci were FCH-positive FDG-negative (57/59 = 97 % on-site and 56/60 = 93 % on masked reading); they were more frequently observed than matched foci in the head and neck region.. These findings suggest that PET/CT performed for suspected relapsing or progressive MM would reveal more lesions when using FCH rather than FDG.

Topics: Aged; Aged, 80 and over; Choline; Disease Progression; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Multiple Myeloma; Pilot Projects; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Recurrence; Reproducibility of Results; Sensitivity and Specificity