RT Journal Article SR Electronic T1 Chocolate Intake Associated with Failed Labeling of 99mTc Red Blood Cells JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP 107 OP 110 DO 10.2967/jnmt.109.061903 VO 37 IS 2 A1 Hussam Bustani A1 Cecile Colavolpe A1 Isabelle Imbert-Joscht A1 Patrick Havlik A1 Pascale Pisano A1 Benjamin Alain Guillet YR 2009 UL http://tech.snmjournals.org/content/37/2/107.abstract AB Red blood cells (RBC) labeled in vivo with 99mTc-pertechnetate are used worldwide in nuclear medicine departments. Methods: Here, we present a case of 99mTc-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 99mTc free fraction (34.1% ± 11.3% vs. 14.0% ± 1.2%). Conclusion: 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.