NUCLEAR PHARMACY The Effects of Selected Antineoplastic Agents on the Labeling of Erythrocytes with Technetium-99m Using the UltraTagt RBC Kit

Objective: Adverse affects of various drugs on the labeling efficiency of RBCs with 99mTc-pertechnetate have been known for several years. This study presents data on the ability of the UltraTagt RBC kit to label RBCs with pertechnetate in the presence of various antineoplastic drugs. Methods: Five different antineoplastic drugs, either alone or in combination, were incubated for 30 min at 37 ° C with 2-mL samples of whole blood obtained from normal volunteers. Each sample was labeled with pertechnetate and the radio-chemical purity determined according to the UltraTag RBC product package insert. Doxorubicin was specifically tested in molar ratios with stannous ion of greater than 1:1 to deter-mine if there was any significant chelation effect that would affect the ability of the kit to label RBCs. In addition, patients were given a bolus injection of doxorubicin and a blood sample was drawn at 30 min to test whether the metabolites had any effect on labeling. Results: The ability of the UltraTag RBC kit to label RBCs with pertechnetate was not adversely affected by the antineo-plastic drugs when they were present alone or in combina-tion. Likewise, doxorubicin metabolites did not interfere with the labeling efficiency of 99mTc RBCs using the UltraTag RBC kit. Molar ratios of doxorubicin-to-tin that exceeded 1:1 also had no adverse effects on the labeling efficiency of the UltraTag RBC kit. Conclusion: When performing nuclear medicine exams involving the labeling of RBCs with pertechnetate on patients who have received doxorubicin, as well as certain other antineoplastic agents, a high RBC labeling efficiency can be obtained if the UltraTag RBC kit is used. Key Words: UltraTagt RBC kit; antineoplastics; labeling interferenc