Double-strand breaks in lymphocyte DNA of humans exposed to [18F]fluorodeoxyglucose and the static magnetic field in PET/MRI

Abstract

Background: Given the increasing clinical use of PET/MRI, potential risks to patients from simultaneous exposure to ionising radiation and (electro)magnetic fields should be thoroughly investigated as a precaution. With this aim, the genotoxic potential of 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) and a strong static magnetic field (SMF) were evaluated both in isolation and in combination using the γH2AX assay detecting double-strand breaks in lymphocyte DNA. Methods: Thirty-two healthy young volunteers allocated to three study arms were exposed to [ 18 F]FDG alone, to a 3-T SMF alone or to both combined over 60 min at a PET/CT or a PET/MRI system. Blood samples taken after in vivo exposure were incubated up to 60 min to extend the irradiation of blood by residual [ 18 F]FDG within the samples and the time to monitor the γH2AX response. Absorbed doses to lymphocytes delivered in vivo and in vitro were estimated individually for each volunteer exposed to [ 18 F]FDG. γH2AX foci were scored automatically by immunofluorescence microscopy. Results: Absorbed doses to lymphocytes exposed over 60 to 120 min to [ 18 F]FDG varied between 1.5 and 3.3 mGy. In this time interval, the radiotracer caused a significant median relative increase of 28% in the rate of lymphocytes with at least one γH2AX focus relative to the background rate (p = 0.01), but not the SMF alone (p = 0.47). Simultaneous application of both agents did not result in a significant synergistic or antagonistic outcome (p = 0.91). Conclusion: There is no evidence of a synergism between [ 18 F]FDG and the SMF that may be of relevance for risk assessment of PET/MRI.

The effect of data aggregation on dispersion estimates in count data models

“…However, statistical work to quantify this relationship and facilitate the actual dose estimation has only been carried out quite recently [10][11][12]. It should be noted that -H2AX foci data is not only used for biological dosimetry but much more prominently for several research questions in radiation biology [13][14][15][16].…”

A revised compartmental model for biokinetics and dosimetry of 2-[18F]FDG

“…Following data were considered for the model construction: For blood: time-resolved activity of 2-[ 18 F]FDG recently obtained within the study by Brix et al [ 21 ] from 32 healthy young adult volunteers and the data provided separately for plasma and erythrocytes of five adult volunteers by Hays and Segall [ 4 ]; For heart wall, liver, lungs: activities of 2-[ 18 F]FDG measured by Hays and Segall [ 4 ] up to 95 min post-injection (p.i. ); For brain, kidneys, spleen and pancreas: data published by Mejia et al [ 6 ] and Deloar et al [ 7 ] for, respectively, 18 and six normal volunteers.…”

“…For blood: time-resolved activity of 2-[ 18 F]FDG recently obtained within the study by Brix et al [ 21 ] from 32 healthy young adult volunteers and the data provided separately for plasma and erythrocytes of five adult volunteers by Hays and Segall [ 4 ];…”

EANM position paper on the role of radiobiology in nuclear medicine

“…In diagnostic nuclear medicine applications, especially in longitudinal procedures, the role of radiobiology and the longterm consequences of radiobiology-related findings, such as reported in studies on DNA damage and repair, still has to be defined [95][96][97][98][99][100][101]. Currently, these studies provide no evidence that diagnostic nuclear medicine procedures are not safe.…”