Christos Sachpekidis, Abstract Co-Author: Nothing to Disclose

Elias K. Loos, Abstract Co-Author: Nothing to Disclose

Hartmut Goldschmidt MD, Abstract Co-Author: Nothing to Disclose

Uwe Haberkorn MD, Abstract Co-Author: Nothing to Disclose

Dirk Hose, Abstract Co-Author: Nothing to Disclose

Georgia Dimitrakopoulou MD, Presenter: Nothing to Disclose

Jens Hillengass MD, Abstract Co-Author: Nothing to Disclose

Antonia Dimitrakopoulou-Strauss, Abstract Co-Author: Nothing to Disclose

To evaluate the distribution patterns and pharmacokinetics of 18F-FDG in patients (pts) suffering from primary multiple myeloma (MM), in correlation with low-dose CT findings and bone marrow plasma cell infiltration rate.

40 pts suffering from primary MM underwent 18F-FDG dynamic PET/CT (dPET/CT) over the lower lumbar spine and pelvis, as well as whole body PET/CT. The evaluation of dPET/CT studies was based in addition to the conventional visual (qualitative) assessment, on semi-quantitative (SUV) calculations, as well as on absolute quantitative estimations after application of a 2-tissue compartment model. Sites of focal 18F-FDG uptake were considered positive for myelomatous involvement, after taking into account the patient’s history. Bone marrow of the os ilium without pathologic tracer accumulation served as reference. The myeloma indicative 18F-FDG avid lesions were compared with low-dose CT findings. The tracer distribution patters and kinetics were correlated with bone marrow plasma cell infiltration rate, as derived from aspirates from the os ilium. The results were considered significant for p<0.01.

In total, 265 focal myeloma indicative 18F-FDG avid lesions were detected, 129 of which correlated with low-dose CT osteolytic findings. Correlation analysis between tracer kinetics and the results of bone marrow biopsies revealed that bone marrow plasma cell infiltration rate correlated significantly with SUVaverage and the parameters k1, influx and FD of 18F-FDG in reference bone marrow. Furthermore, whole body static PET/CT imaging demonstrated four patterns of tracer uptake: negative, focal, diffuse and mixed (focal/diffuse) tracer uptake. Patients with a mixed pattern of radiotracer uptake had the highest mean plasma cell infiltration rate in their bone marrow, while those with negative PET/CTs demonstrated the lowest bone marrow plasma cell infiltration.

The 18F-FDG kinetic parameters k1, influx and FD as well as SUVaverage from reference tissue correlated significantly with bone marrow malignant plasma cell infiltration rate. There was a 49% correlation between 18F-FDG PET/CT and low-dose CT myeloma indicative findings.

We study the distribution patterns and pharmacokinetics of 18F-FDG PET in correlation with results of bone marrow biopsy and low-dose CT findings. To our knowledge, this is the first study trying to evaluate this correlation.

Sachpekidis, C, Loos, E, Goldschmidt, H, Haberkorn, U, Hose, D, Dimitrakopoulou, G, Hillengass, J, Dimitrakopoulou-Strauss, A, 18F-FDG PET/CT in Primary Multiple Myeloma: Correlation of Distribution Patterns and Tracer Kinetics with CT Findings and Bone Marrow Biopsy Results.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007172.html