Journal of Nuclear Medicine Technology, Vol 26, Issue 4 265-268, Copyright © 1998 by Society of Nuclear Medicine
Evaluation of technetium-99m red blood cell labeling efficiency in adults receiving chemotherapy and the clinical impact on pediatric oncology patients
MP White, A Mann, DM Cross and GV Heller
Nuclear Cardiology Laboratory, Division of Cardiology, Hartford Hospital, Connecticut, USA.
OBJECTIVE: Technetium-99m-labeled RBCs are used to evaluate ventricular
function and are the preferred method for monitoring the cardiac function
of patients receiving chemotherapy. Optimal imaging quality is critical for
monitoring small but important changes in ventricular function. The
labeling efficiency of three products from two manufacturers and images
from 30 patients (21 men, 9 women; age 60.3 +/- 11.9 yr) referred for
clinical radionuclide ventriculograms before chemotherapy were evaluated to
determine the best labeling technique. METHODS: Patients received RBCs
labeled in one of three ways. Two pyrophosphate methods used a modified in
vitro method and the manufacturer's instructions were used for the in vitro
method. Imaging was performed and, upon completion (42.1 +/- 9.6 min),
blood samples were drawn, separated and counted to determine labeling
efficiency. RESULTS: The labeling efficiencies were: (a) 88.1% +/- 4.2% and
(b) 88.4% +/- 4.8% for the two modified in vitro methods; and (c) 95.3% +/-
1.7% for the in vitro method. The difference between the methods was
statistically significant (p = 0.019). Twenty pediatric oncology patients
(6.4 +/- 5.2 yr) received in vitro labeled RBCs through their Hickman
catheters. All 20 pediatric studies were of high quality. CONCLUSION: In
vitro labeling demonstrated a higher labeling efficiency than the modified
in vitro methods. In vitro labeling also yielded high-quality images when
the labeled RBCs were injected through existing chronic in-dwelling
catheters.
