FDG-PET/CT assessment of differential chemotherapy effects upon skeletal muscle metabolism in patients with melanoma.

OBJECTIVES

To quantify the differential effects of chemotherapy on the metabolic activity of skeletal muscle in vivo using molecular imaging with [18F]-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT).

METHODS

In this retrospective study, 21 subjects with stage IV melanoma who underwent pre- and post-chemotherapy whole-body FDG-PET/CT imaging were included. The mean standardized uptake value (SUVmean) of 8 different skeletal muscles was measured per subject. Pre- and post-treatment measurements were then averaged across all subjects for each muscle and compared for statistically significant differences between the muscles and following different chemotherapy regimens including dacarbazine (DTIC) and temozolomide (TMZ).

RESULTS

Analysis of FDG-PET/CT images reliably detected changes in skeletal muscle metabolic activity based on muscle location. The percent change in metabolic activity of each skeletal muscle in each subject following chemotherapy was observed to be related to the type of chemotherapy received. Subjects receiving DTIC generally had a decrease in metabolic activity of all muscle groups, whereas subjects receiving TMZ generally had an increase in muscle activity of all muscle groups.

CONCLUSION

FDG-PET/CT can reveal baseline metabolic differences between different muscles of the body. Different chemotherapies are associated with differential changes in the metabolic activity of skeletal muscle, which can be detected and quantified with FDG-PET/CT.