DOSAGE AND ADMINISTRATION
DaTscan emits radiation and must be handled with safety
measures to minimize radiation exposure to clinical personnel and patients.
Radiopharmaceuticals should be used by or under the control of physicians who
are qualified by specific training and experienced in the safe use and handling
of radionuclides, and whose experience and training have been approved by the
appropriate government agency authorized to license the use of radionuclides.
DaTscan dosing is based upon the radioactivity determined using a suitably
calibrated instrument immediately prior to administration.
To minimize radiation dose to the bladder, encourage
hydration prior to and following DaTscan administration in order to permit
frequent voiding. Encourage the patient to void frequently for the first 48
hours following DaTscan administration [see Radiation Dosimetry].
Thyroid Blockade Before DaTscan Injection
Before administration of DaTscan, administer Potassium
Iodide Oral Solution or Lugol's Solution (equivalent to 100 mg iodide) or
potassium perchlorate (400 mg) to block uptake of iodine 123 by the patient's
thyroid. Administer the blocking agent at least one hour before the dose of
DaTscan [see WARNINGS AND PRECAUTIONS].
Preparation And Administration
Use aseptic procedures and radiation shielding during
preparation and administration. Inspect the DaTscan vial prior to
administration and do not use it if the vial contains particulate matter or
discoloration [see DESCRIPTION]. Administer DaTscan as a slow
intravenous injection (administered over a period of not less than 15 to 20 seconds)
via an arm vein.
The recommended dose is 111 to 185 MBq (3 to 5 mCi)
administered intravenously [see Clinical Studies].
The estimated radiation absorbed doses to an average
adult from intravenous injection of DaTscan are shown in Table 1. The values
are calculated assuming urinary bladder emptying at 4.8-hour intervals
and appropriate thyroid blocking (iodine 123 is a known Auger electron
Table 1: Estimated Radiation Absorbed Doses from DaTscan
|Small Intestine Wall
|Upper Large Intestine Wall
|Lower Large Intestine Wall
|Urinary Bladder Wall
|EFFECTIVE DOSE PER UNIT ADMINISTERED
|a-The absorbed dose to the colon wall is the
mass-weighted sum of the absorbed doses to the upper and lower large
intestine walls, Dcolon = 0.57DULI + 0.43DLLI [Publication 80 of the ICRP
(International Commission on Radiological Protection); Annals of the ICRP 28
(3). Oxford: Pergamon Press; 1998]
The Effective Dose resulting from a DaTscan
administration with an administered activity of 185 MBq (5 mCi) is 3.94 mSv in
Begin SPECT imaging 3 to 6 hours following DaTscan
administration. Acquire images using a gamma camera fitted with high-resolution
collimators and set to a photopeak of 159 keV with a ± 10% energy window.
Angular sampling should be not less than 120 views over 360 degrees. Position
the subject supine with the head on an off-the- table
headrest, a flexible head restraint such as a strip of tape across the chin or forehead
may be used to help avoid movement, and set a circular orbit for the detector
heads with the radius as small as possible (typically 11 to 15 cm). Experimental
studies with a striatal phantom suggest that optimal images are obtained with
matrix size and zoom factors selected to give a pixel size of 3.5 to 4.5 mm.
Collect a minimum of 1.5 million counts for optimal images.
DaTscan images are interpreted visually, based upon the
appearance of the striata. Reconstructed pixel size should be between 3.5 and
4.5 mm with slices 1 pixel thick. Optimum presentation of the reconstructed
images for visual interpretation is transaxial slices parallel to the anterior
commissure-posterior commissure (AC-PC) line. Determination
of whether an image is normal or abnormal is made by assessing the extent (as
indicated by shape) and intensity of the striatal signal. Image interpretation
does not involve integration of the striatal image appearance with clinical signs
In transaxial images, normal images are characterized by
two symmetric comma- or crescent-shaped focal regions of
activity mirrored about the median plane. Striatal activity is distinct,
relative to surrounding brain tissue (Figure 1).
Abnormal DaTscan images fall into at least one of the
following three categories (all are considered abnormal).
- Activity is asymmetric, e.g. activity in the region of
the putamen of one hemisphere is absent or greatly reduced with respect to the
other. Activity is still visible in the caudate nuclei of both hemispheres
resulting in a comma or crescent shape in one and a circular or oval focus in
the other. There may be reduced activity between at least one striatum and
surrounding tissues (Figure 2).
- Activity is absent in the putamen of both hemispheres and
confined to the caudate nuclei. Activity is relatively symmetric and forms two
roughly circular or oval foci. Activity of one or both is generally reduced
- Activity is absent in the putamen of both hemispheres and
greatly reduced in one or both caudate nuclei. Activity of the striata with
respect to the background is reduced (Figure 4).
Figure 1,2,3 and 4
Dosage Forms And Strengths
Single-use vials containing 185 MBq (5 mCi) in
2.5 mL sterile solution for intravenous injection [74 MBq (2 mCi) per mL at
Storage And Handling
DaTscan is supplied in 10-mL glass vials containing a
total volume of 2.5 mL of solution with a total radioactivity of 185 MBq (5
mCi) at calibration time. Each vial is enclosed in a lead container
Store DaTscan at 20° to 25°C (68° to 77°F). This product
does not contain a preservative. Store DaTscan within the original lead
container or equivalent radiation shielding.
Do not use DaTscan (Ioflupane I 123 Injection)
preparations after the expiration date and time stated on the label.
This preparation is approved for use by persons licensed
by the Illinois Emergency Management Agency pursuant to 32 IL. Adm. Code
Section 330.260(a) and 335.4010 or equivalent licenses of the Nuclear
Regulatory Commission or an Agreement State.
Manufactured and Distributed by : GE Healthcare, Medi-Physics,
Inc., Arlington Heights, IL 60004 U.S.A. Revised September 2015