TY - JOUR T1 - Chocolate Intake Associated with Failed Labeling of <sup>99m</sup>Tc Red Blood Cells JF - Journal of Nuclear Medicine Technology JO - J. Nucl. Med. Technol. SP - 107 LP - 110 DO - 10.2967/jnmt.109.061903 VL - 37 IS - 2 AU - Hussam Bustani AU - Cecile Colavolpe AU - Isabelle Imbert-Joscht AU - Patrick Havlik AU - Pascale Pisano AU - Benjamin Alain Guillet Y1 - 2009/06/01 UR - http://tech.snmjournals.org/content/37/2/107.abstract N2 - 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. ER -