RT Journal Article
SR Electronic
T1 Effect of extravasation on optimal timing of oncologic FDG PET
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1413
OP 1413
VO 57
IS supplement 2
A1 Lee, Jong Jin
A1 Chung, Jin Hwa
A1 Kim, Seog-Young
YR 2016
UL http://jnm.snmjournals.org/content/57/supplement_2/1413.abstract
AB 1413Objectives Aims of this study were 1) to investigate the effect of extravasation on tumoral time activity curve according to the extravasated amount in animal xenograft tumor model on 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and 2) to find the temporal change of tumoral standardized uptake value (SUV) according to the extravasated amount in human oncologic FDG PET.Methods For animal experiment, FDG extravasations at tails were done in HCT116 bearing mice xenograft tumor model making 3 groups (no extravasation, 40% extravasation, 80% extravasation, each n=5). Dynamic animal PET scans were done for two hours. Time activity curves were obtained for extravasation site and tumors. For human PET, which were done 1 hour after FDG injection, following scans were included: 1) patient who had undergone both whole body and subsequent additional regional scans, 2) entire extravasated activity included in the whole body scan, 3) lesion included on both whole body and additional regional scan, and 4) lesion was either biopsy proven or clinically suspected for malignancy. SUVs of tumor (both on whole body and additional PET images) and extravasation site were recorded.Results In animal experiment, times to reach a plateau at tumor were not different between 3 extravasation groups. Times to reach a minimum at extravasation site were not different between 3 extravasation groups, either. However, tumoral mean activity and activity at the extravasation site showed negative correlation 1 hour after injection. In human PET, 22 cases were enrolled (M:F=14:8, age: 70.8±9.2 yrs). SUV changes between whole body and additional PET images did not show significant correlation with interval between injection and whole body scan start time, interval between whole body scan start time and additional scan start time and activity at extravasation site.Conclusions Even extensive extravasation did not affect the tumor uptake plateau time. Thus, in routine practice, even though extravasation was identified, imaging time that is 60 minutes after FDG injection needs not to be modified. However, tumor SUV itself can be underestimated in case of extravasation.