2. After radiolabelling with sodium pertechnetate (99mTc) solution, the solution of technetium (99mTc) tetrofosmin obtained is indicated for: Myocardial Imaging Technetium (99mTc) tetrofosmin is a myocardial perfusion agent indicated as an adjunct in the diagnosis and localization of myocardial ischaemia and/ or infarction.
In patients undergoing myocardial perfusion scintigraphy, ECG-gated SPECT can be used for assessment of left ventricular function (left ventricular ejection fraction and wall motion). g. palpation, mammography, or alternative imaging modalities and/or cytology) in the characterisation of malignancy of suspected breast lesions where all these other recommended tests were inconclusive.
2 Posology and method of administration Adults and elderly population Posology may vary depending on gamma camera characteristics and reconstruction modalities. The injection of activities greater than local DRLs (Diagnostic Reference Levels) should be justified.
The recommended activity range for intravenous administration to an adult patient of average weight (70 kg) is for: Myocardial Imaging For diagnosis and localization of myocardial ischaemia (using planar or SPECT techniques) and assessment of left ventricular function using ECG-gated SPECT, the usual procedure involves two intravenous injections of technetium (99mTc) tetrofosmin, one given at peak stress and one given at rest.
The order of the two administrations can be either rest first and stress second or stress first and rest second. When rest and stress injections are administered on the same day, the activity administered for the second dose should result in a myocardial count rate at least three times greater than that of the residual activity from the first dose.
The recommended activity range for the first dose is 250 - 400 MBq; the recommended activity range for the second dose given at least 1 hour later, is 600 - 800 MBq. For studies employing ECG-gated SPECT, use of activities at the higher end of these ranges is warranted.
When rest and stress injections are administered on different days, the recommended activity range for each dose technetium (99mTc) tetrofosmin is 400 - 600 MBq. g. those with abdominal obesity or women with large breasts) and for those employing ECG-gated SPECT, use of activities at the higher end of this range is warranted.
The total activity administered for stress and rest myocardial imaging studies, whether performed on one or two days, should be restricted to 1200 MBq. As an adjunct in the diagnosis and localization of myocardial infarction, one injection of technetium (99mTc) tetrofosmin (250 - 400 MBq) at rest is sufficient.
Breast Imaging For the diagnosis and localization of suspected breast lesions, the recommended procedure involves a single intravenous injection of technetium (99mTc) tetrofosmin between 500 – 750 MBq. The injection should preferably be given in a foot vein or a site other than the arm on the side of the suspected breast lesion.
Renal impairment Careful consideration of the activity to be administered is required since an increased radiation exposure is possible in these patients. Hepatic impairment In general, activity selection for patients with a decreased hepatic function should be cautious, usually starting at the low end of the dosing range.
Paediatric population The use in children and adolescents has to be considered carefully, based upon clinical needs and assessing the risk/benefit ratio in this patient group. The activities to be administered to children and adolescents may be calculated according to the recommendations of the European Association of Nuclear Medicine (EANM) paediatric dosage card; the activity administered to children and to adolescents may be calculated by multiplying a baseline activity (for calculation purposes) by the weight-dependent multiples given in the table below.
A [MBq] Administered = Baseline Activity × Multiple The baseline activity is 63 MBq as a cancer seeking agent. For cardiac imaging, the minimum and maximum baseline activities are 42 and 63 MBq, respectively, for the two-day protocol cardiac scan both at rest and stress.
For the one-day cardiac imaging protocol, the baseline activity is 28 MBq at rest and 84 MBq at stress. The minimum activity for any imaging study is 80 MBq. 00 Image acquisition Myocardial Imaging Planar or preferably SPECT imaging should begin not earlier than 15 minutes post- injection.
There is no evidence for significant changes in myocardial concentration or redistribution of technetium (99mTc) tetrofosmin, therefore, images may be acquired up to at least four hours post-injection. For planar imaging the standard views (anterior, LAO 40°- 45°, LAO 65°- 70° and/or left lateral) should be acquired.
Breast Imaging Breast imaging is optimally initiated 5 – 10 minutes post injection with the patient in the prone position with the breast(s) freely pendant. A special imaging couch designed for nuclear medicine breast imaging is recommended.
A lateral image of the breast suspected of containing lesions should be obtained with the camera face as close to the breast as is practicable. The patient should then be repositioned so that a lateral image of the pendant contralateral breast can be obtained.
An anterior supine image may then be obtained with the patient’s arms behind her head. 4.