The effects of music and darkness on radionuclide distribution during mice FDG-PET scan

Abstract

Background: There is growing interest in the therapeutic potential of music or light in different human disorders.

Aims: This study aimed to evaluate the effects of music as well as darkness on FDG uptake in 4T1 tumor-bearing BALB/c mice using a PET scan.

Methods: The music, darkness, and music plus darkness groups were subjected to either song or darkness and their combination, respectively, 30 min before the radiopharmaceutical injection until the end of the experiments. The control group was imaged in silence under ambient conditions.

Results: Our results revealed that music did not significantly alter the range of tumor SUVmean, but showed a slight increase in brain SUVmean (18.2%) and about 100% increase in brain percentage of injected dose per gram (%ID/g) in ex vivo analysis. In contrast, heart SUVmean and heart %ID/g were approximately half those of the silence group. The muscle SUVmean and blood activity measurements showed a decrement upon music exposure. Also, results showed a significant difference in tumor-to-muscle ratio (85% increment) and brain-to-muscle ratio (105% increment) between the silence and music groups. The muscle SUVmean decreased by 50%, and tumor-to-muscle and brain-to-muscle ratios were observed to increase by 44% and 60% in the group exposed to darkness, respectively.

Conclusion: Our results suggest that music and environmental factors may influence FDG uptake in small-animal PET imaging, and provide important insights into the reliability of FDG-PET imaging for music intervention research and may aid researchers in investigating the effects of music on brain changes and tissue metabolism.

Keywords: Light; Music intervention; Preclinical imaging; Small-animal PET; Tumor.

Fig. 1

Maximum intensity projection (MIP) views of FDG_PET scans of four different female BALB/C mice with 4T1 tumors in the right flanks of animals (white arrows). The animals are selected from silent-light (a), music-light (b), silent-dark (c), and music-dark (d) groups. The images represent acquired data 60 min after FDG injection

Fig. 2

Quantitative analysis of the FDG-PET images. Calculated SUVmean (a), tissue-to-muscle ratio (b), tumor-to-brain ratio (TBR) (c), measured %ID/g for tumor, brain, heart, liver, kidney and muscle (d), and blood %ID/uL (e) for scanned animals in silent-light, music-light, silent-dark, and music-dark groups. Mean values and standard deviations are shown for each group. All groups were compared with the silent-light group as the control (^* P<0.05). Additionally, we compared the music-light and music-dark groups (# P<0.05)