Chocolate intake associated with failed labeling of (99m)Tc red blood cells.
Red blood cells (RBC) labeled in vivo with (99m)Tc-pertechnetate are used worldwide in nuclear medicine departments.


METHODS
Here, we present a case of (99m)Tc-RBC labeling failure associated with chocolate intake in a 25-y-old woman, resulting in uninterpretable images. Because of this clinical observation, we performed in vitro RBC labeling on blood samples from volunteers after they consumed chocolate.


RESULTS
Chocolate intake inhibited the labeling rate, compared with the control condition, and significantly increased the (99m)Tc free fraction (34.1% +/- 11.3% vs. 14.0% +/- 1.2%).


CONCLUSIONS
We cannot explain how this interaction could occur, but cacao components are known to modulate red cell and plasma oxidoreductive status and to modify red cell membrane permeability and plasticity. Therefore, for patients who can be considered likely to consume chocolate, such as young patients, we recommend that they limit their consumption of chocolate for 12 h before RBC labeling.
Bustani
Hussam
H
Radiopharmacie, CHU Nord, Marseille, France.
Colavolpe
Cecile
C
Imbert-Joscht
Isabelle
I
Havlik
Patrick
P
Pisano
Pascale
P
Guillet
Benjamin Alain
BA
D000328:Adult; D002099:Cacao; D004435:Eating; D004912:Erythrocytes / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015635:Radionuclide Ventriculography; D013670:Sodium Pertechnetate Tc 99m / Q000378:metabolism*; D013194:Staining and Labeling
D013670:Sodium Pertechnetate Tc 99m