DATSCAN

11.1 Chemical Characteristics DATSCAN (ioflupane I 123 injection) is a sterile, pyrogen-free radioactive diagnostic agent for intravenous use. DATSCAN is a clear and colorless solution supplied in single-dose vials. Each milliliter contains 0.07 to 0.13 mcg ioflupane, 74 MBq (2 mCi) of iodine-123 (as ioflupane I 123) at calibration time, 5.8 mg acetic acid, 8.2 mg sodium acetate and 0.05 mL (5%) ethanol. The pH of the solution is between 4.2 and 5.2. The chemical name for ioflupane I 123 is N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-[ 123 I]iodophenyl)nortropane and it has the following structural formula: Chemical Structure 11.2 Physical Characteristics Iodine-123 is a cyclotron-produced radionuclide that decays to tellurium-123 by electron capture and has a physical half-life of 13.2 hours. The photon that is useful for detection and imaging studies is listed in Table 2. Table 2 Principal Radiation Emission Data – Iodine-123 Radiation Energy Level (keV) Abundance (%) Gamma 159 83 11.3 External Radiation The specific gamma-ray constant for iodine-123 is 1.6 R/mCi-hr at 1 cm. The first half-value thickness of lead (Pb) for iodine-123 is 0.04 cm. The relative transmission of radiation emitted by the radionuclide that results from interposition of various thicknesses of Pb is shown in Table 3 (e.g., the use of 2.16 cm Pb will decrease the external radiation exposure by a factor of about 1,000). Table 3 Reduction in In-air Collision Kerma Caused by Lead Shielding Calculation based on attenuation and energy-transfer coefficients obtained from National Institute of Standards & Technology Internal Report NISTIR 5632. Shield Thickness cm of lead (Pb) Reduction in In-air Collision Kerma 0.04 0.5 0.13 10 -1 0.77 10 -2 2.16 10 -3 3.67 10 -4

DATSCAN is indicated as an adjunct to other diagnostic evaluations for striatal dopamine transporter visualization using single photon emission computed tomography (SPECT) brain imaging in adult patients with: suspected Parkinsonian syndromes (PS) or suspected dementia with Lewy bodies (DLB). DATSCAN is a radioactive diagnostic agent indicated as an adjunct to other diagnostic evaluations for striatal dopamine transporter visualization using single photon emission computed tomography (SPECT) brain imaging in adult patients with: suspected Parkinsonian syndromes (PS) or suspected dementia with Lewy bodies (DLB). ( 1 )

Administer a thyroid-blocking agent at least one hour before the dose of DATSCAN. ( 2.2 ) The recommended dose of DATSCAN in adult patients is 111 MBq to 185 MBq (3 mCi to 5 mCi) administered intravenously over at least 20 seconds. ( 2.3 ) Measure patient dose using a dose calibrator immediately prior to administration. ( 2.4 ) Begin SPECT imaging between 3 hours and 6 hours post-injection. ( 2.6 ) 2.1 Radiation Safety DATSCAN emits radiation and must be handled with safety measures to minimize radiation exposure to healthcare providers and patients [see Warnings and Precautions (5.3) ] . Radiopharmaceuticals should be used by or under the control of healthcare providers 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. To minimize radiation exposure, 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 Dosage and Administration (2.5) ] . 2.2 Thyroid Blockade Before DATSCAN Administration Administer Potassium Iodide Oral Solution or Strong Iodine Solution (e.g., Lugol's Solution) equivalent to 100 mg iodide to block uptake of iodine-123 by the patient's thyroid at least one hour before the dose of DATSCAN [see Warnings and Precautions (5.2) ] . 2.3 Recommended Dosage The recommended dose of DATSCAN in adult patients is 111 MBq to 185 MBq (3 mCi to 5 mCi) administered intravenously over at least 20 seconds. 2.4 Preparation and Administration Assess pregnancy status before administering DATSCAN to a female of reproductive potential [see Use in Specific Populations (8.1) ] . Use aseptic procedures and radiation shielding during preparation and administration. Inspect the DATSCAN vial for particulate matter and discoloration prior to administration and do not use it if the vial contains particulate matter or discoloration. Measure patient dose using a dose calibrator immediately prior to administration. Discard unused portion. 2.5 Radiation Dosimetry The estimated radiation absorbed doses to an 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 emitter). Table 1 Estimated Radiation Absorbed Doses from DATSCAN ORGAN / TISSUE ABSORBED DOSE PER UNIT ADMINISTERED ACTIVITY (µGy / MBq) Adrenals 12.9 Brain 17.8 Striata 230 Breasts 7.8 Gallbladder Wall 26.4 GI Tract Esophagus 10 Stomach Wall 11.2 Small Intestine Wall 21.2 Colon Wall The absorbed dose to the colon wall is the mass-weighted sum of the absorbed doses to the upper and lower large intestine walls, D colon = 0.57D ULI + 0.43D LLI [Publication 80 of the ICRP (International Commission on Radiological Protection); Annals of the ICRP 28 (3). Oxford: Pergamon Press; 1998] 39.8 Upper Large Intestine Wall 38.1 Lower Large Intestine Wall 42 Heart Wall 12.9 Kidneys 10.9 Liver 27.9 Lungs 41.2 Muscle 9.4 Osteogenic Cells 28.2 Ovaries 16.8 Pancreas 13 Red Marrow 9.2 Skin 6 Spleen 10.4 Testes 8.5 Thymus 10 Thyroid 9 Urinary Bladder Wall 53.1 Uterus 16.1 Total Body 11.3 EFFECTIVE DOSE PER UNIT ADMINISTERED ACTIVITY (µSv/MBq) 21.3 The Effective Dose resulting from a DATSCAN administration with an administered activity of 185 MBq (5 mCi) is 3.94 mSv in an adult. 2.6 Imaging Instructions Begin SPECT imaging 3 hours to 6 hours following DATSCAN administration. Use 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 at least 120 views over 360 degrees. Position the patient supine with the head on an off-the-table headrest, use a flexible head restraint such as a strip of tape across the chin or forehead if necessary to help avoid movement, and set a circular orbit for the detector heads with the radius as small as possible (typically 11 cm to 15 cm). Obtain images with matrix size and zoom factors selected to give a pixel size of 3.5 mm to 4.5 mm. Collect a minimum of 1.5 million counts for optimal images. 2.7 Image Interpretation Interpret DATSCAN images visually, based upon the appearance of the striata. Reconstructed pixel size should be between 3.5 mm 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. Determine whether an image is normal or abnormal 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 and/or symptoms. Normal: 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: 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 (Figure 3). 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). Figures 1-4

DATSCAN is contraindicated in patients with known serious hypersensitivity to ioflupane I 123 [see Warnings and Precautions (5.1) ] . Known serious hypersensitivity to ioflupane I 123 ( 4 )

The following clinically significant adverse reaction is described elsewhere in the labeling: Hypersensitivity Reactions [see Warnings and Precautions (5.1) ] The following adverse reactions were reported at ≤1%: headache, nausea, vertigo, dry mouth and dizziness. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact GE Healthcare at 1-800-654-0118 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of DATSCAN cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The data from clinical trials reflect exposure to DATSCAN in 942 subjects with a mean age of 66 years (range 25 years to 90 years). Among these subjects, 42% were female and 99% White. Subjects received 88 MBq to 287 MBq (2 mCi to 8 mCi) [median 173 MBq (4.7 mCi)] intravenously as a single dose. The recommended dose of DATSCAN is 111 MBq to 185 MBq (3 mCi to 5 mCi) [see Dosage and Administration (2.3) ]. The following adverse reactions were reported at a rate of 1% or less: headache, nausea, vertigo, dry mouth, and dizziness. 6.2 Postmarketing Experience The following adverse reactions have been identified during postapproval use of DATSCAN. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Immune system disorders : Hypersensitivity, including dyspnea, edema, rash, erythema, and pruritus General disorders and administration site conditions : Injection site pain

Ioflupane I 123 binds to the dopamine transporter [see Clinical Pharmacology (12.1) ] . Drugs that bind to the dopamine transporter with high affinity may interfere with the image obtained following DATSCAN administration. These potentially interfering drugs consist of: amoxapine, amphetamine, armodafinil, benztropine, bupropion, buspirone, cocaine, mazindol, methamphetamine, methylphenidate, modafinil, norephedrine, phentermine, phenylpropanolamine, selegiline, and sertraline. Selective serotonin reuptake inhibitors (paroxetine and citalopram) may increase or decrease ioflupane binding to the dopamine transporter. Whether discontinuation of these drugs prior to DATSCAN administration may minimize the interference with a DATSCAN image is unknown. The impact of dopamine agonists and antagonists upon DATSCAN imaging results has not been established. Amoxapine, amphetamine, armodafinil, benztropine, bupropion, buspirone, cocaine, mazindol, methamphetamine, methylphenidate, modafinil norephedrine, phentermine, phenylpropanolamine, selegiline, sertraline, citalopram and paroxetine may interfere with DATSCAN imaging. The effects of dopamine agonists and antagonists on DATSCAN imaging have not been established. ( 7 )

Storage and Handling 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 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 the relevant regulatory authority of an Agreement State.