90Y-microspheres therapy is used to treat selected patients with primary or metastatic liver tumors in a safe and effective way. As a preparation for 90Y-microspheres treatment, a 99mTc-macroaggregated albumin (99mTc-MAA) simulation procedure is essential to evaluate particle shunting to the lung or gastrointestinal tract. We investigated the effect of interval between injection of 99mTc-MAA and time of scanning on the lung shunt fraction (LSF). In 4 patients with secondary hepatic malignancies who underwent repeated whole-body scintigraphy up to 5 hours after injection of 99mTc-MAA, a marked change in LSF was observed. It appears that tracer degradation leads to an important overestimation of LSF at later time points. An overestimation of LSF can lead to dose reduction or canceling of the planned 90Y-microspheres treatment. It is concluded that the interval between injection and scanning should be kept as short as possible.
From the Departments of *Nuclear Medicine; †Radiology; ‡Digestive Oncology; §Radiation Oncology; and ∥Laboratory for Radiopharmacy, University Hospitals Leuven and KU Leuven, Leuven, Belgium.
Received for publication March 15, 2013; revision accepted August 26, 2013.
C.M.D. is a postdoctoral fellow of the Clinical Research Fund of the UZ Leuven.
Conflicts of interest and sources of funding: none declared.
Reprints: Christophe Michel Deroose, MD, PhD, Department of Nuclear Medicine, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium. E-mail: email@example.com.