Nuclear Imaging - Radio pharmaceuticals Technetium (99mTc) sestamibi & Technetium (99mTc) tetrofosmin

1. Technetium (99mTc)
sestamibi
Technetium (99mTc)
tetrofosmin
Amila Abeyweera

2. Technetium (99mTc) Sestamibi

3. Introduction
• Technetium (99mTc) sestamibi is a pharmaceutical agent used in
nuclear medicine imaging.
• trade name - Cardiolite.
• The generic drug became available late September 2008. A scan of a
patient using MIBI is commonly known as a "MIBI scan."
• Cardiolite is mainly used to image the myocardium (heart muscle). It
is also used in the work-up of primary hyperparathyroidism to identify
parathyroid adenomas, for radio guided surgery of the parathyroid
and in the work-up of possible breast cancer.

4. Molecular Structure

5. • IUPAC name
Hexakis(2-methoxy-2-
methylpropylisonitrile)technetium (99mTc)
• The drug is a coordination complex
consisting of the radioisotope
technetium-99m bound to six (sesta=6)
methoxyisobutylisonitrile (MIBI) ligands

6. Each 5ml vial contains the following
ingredients
• 1 mg tetrakis (2-methoxyisobutylisonitrile) copper
(I)tetrafluoroborate
• 0.075 mg stannous chloride dihydrate
• 1 mg cysteine hydrochloride-monohydrate.
• Sodium citrate dehydrate
• Manitole
Cardiolite Kit for radiopharmaceutical
preparation of Technetium Tc-99m Sestamibi
Injection

7. Cardiolite Kit for radiopharmaceutical
preparation of Technetium Tc-99m Sestamibi
Injection
• Prior to adding the Sodium Pertechnetate Tc 99m Injection to the vial, inspect the vial carefully for
the presence of damage, particularly cracks, and do not use the vial if found.
• Waterproof gloves should be worn during the preparation procedure. Remove the plastic disc
from the vial and swab the top of the vial closure with alcohol to sanitize the surface.Place the
vial in a suitable radiation shield with a fitted radiation cap.
• With a sterile shielded syringe, aseptically obtain additive-free, sterile, non-pyrogenic Sodium
Pertechnetate Tc 99m Injection [925– 5550 MBq, (25–150 mCi)] in approximately 1 to 3 mL.

8. • A septically add the Sodium Pertechnetate Tc 99m Injection to the vial in the lead shield. Without
withdrawing the needle, remove an equal volume of headspace to maintain atmospheric
pressure within the vial.
• Shake vigorously, about 5 to 10 quick upward downward motions.
• Remove the vial from the lead shield and place upright in an appropriately shielded and
contained boiling water bath, such that the vial is suspended above the bottom of the bath, and
boil for 10 minutes. Timing for 10 minutes is begun as soon as the water begins to boil again. Do
not allow the boiling water to come in contact with the aluminum crimp.
• R emove the vial from the water bath, place in the lead shield and allow to cool for fifteen
minutes.
• Using proper shielding, the vial contents should be visually inspected. Use only if the solution is
clear and free of particulate matter and discoloration.

9. • Assay the reaction vial using a suitable radioactivity calibration system. Record the Technetium Tc
99m concentration, total volume, assay time and date, expiration time and lot number on the
radio assay information label and affix the label to the shield.
• Store the reaction vial containing the Technetium Tc 99m Sestamibi at 15° to 25°C (59° to 77°F)
until use; at such time the product should be aseptically withdrawn. Technetium Tc 99m Sestamibi
should be used within six hours of preparation. The vial contains no preservative.

10. Applications
• To study blood flow, particularly in the heart
• To help to identify possible breast abnormalities when used with a
mammogram
• To investigate over activity of the parathyroid glands in the neck
(these glands help control the level of calcium in your body)

11. myocardial perfusion stress test

12. A 45-year-old woman with elevated risk for breast cancer due to breast density
underwent digital screening mammogram (left) and screening MBI (right) as part of
a clinical trial. A biopsy from the area of suspicious technetium-99m (Tc-99m)
sestamibi uptake (arrow) indicated the presence of a large lobular carcinoma.

13. Parathyroid imaging

14. Method of administration
• For intravenous use.
• Because of potential tissue damage extravasal injection of this
radioactive product has to be strictly avoided.

15. Elimination
• The major pathway for clearance of Tc 99m Sestamibi is the
hepatobiliary system. Activity from the gall bladder appears in the
intestines within one hour of injection.27% of the injected dose is
excreted in the urine, and approximately 33% of the injected dose is
cleared through the feces in 48 hours.

16. Technetium (99mTc) tetrofosmin

17. Introduction
• Technetium (99mTc) tetrofosmin is a drug used in nuclear
medicine cardiac imaging.
• It is sold under the brand name Myoview.

18. Molecular structure

19. • IUPAC Name –
2-[bis(2-ethoxyethyl)phosphanyl]ethyl-bis(2-
ethoxyethyl)phosphane
• The radioisotope, technetium-99m, is chelated by two 1,2-
bis[di-(2-ethoxyethyl)phosphino]ethane ligands which
belong to the group of diphosphines and which are referred
to as tetrofosmin.

20. PREPARATION OF KIT FOR 99mTc-TETROFOSMIN
Reagents
• 2-Ethoxy ethyl-3,12-dioxa-6,9-diphosphate tetradecane
(tetrofosmin)
• Stannous chloride dihydrate: SnCl2.2H2O
• Disodium sulphosalicylate
• Sodium D-gluconate
• Sodium hydrogen carbonate
• Hydrochloric acid: HCl (concentrated, 1N)
• Sodium hydroxide: NaOH (1N)
• Saline
• Water for injection
• Nitrogen gas.

21. Chemical composition of kit
• Tetrofosmin: 0.25 mg
• Stannous chloride dihydrate50 μg
• Disodium sulphosalicylate: 0.35 mg
• Sodium D-gluconate: 1 mg
• Sodium hydrogen carbonate: 1.8 mg

22. Preparation of kit solution for a final volume of
100 mL
• Use cold water for injection bubbled with N2 gas during solution
preparation.
• Prepare 0.05M sodium bicarbonate buffer by weighing 210 mg of
sodium bicarbonate and dissolving in water for injection to obtain a
final volume of 50 mL; the pH of this buffer will be about 8.5.
• Weigh 50 mg of stannous chloride dihydrate and dissolve in 0.1 mL of
concentrated HCl, with slight warming; dilute the solution with water
for injection to 5 mL in a measuring flask of 50 mL capacity; just prior
to final formulation, dilute this solution to 50 mL with water for
injection and use immediately.

23. • Weigh 25 mg of tetrofosmin and dissolve in 43 mL of 0.05M
bicarbonate buffer (pH8.5).
• Weigh 35 mg of disodium sulfosalicylate and dissolve in 10 mL of
water for injection.
• Weigh 100 mg of sodium D-gluconate and dissolve in 10 mL of water
for injection.
• To the 43 mL solution of tetrofosmin, add 5 mL of freshly prepared
stannous chloride solution, 10 mL of disodium sulfosalicylate solution
and 10 mL of sodium D-gluconate solution; adjust the pH to ~8 by
drop-wise addition of 1N NaOH; adjust the final volume to 100 mL;
mix well and filter the solution through a 0.22 μm sterile filter.
• Dispense 1 mL aliquots per vial
• Precool the vials using liquid nitrogen, or cool them inside the freeze-
dryer.

24. Method of Administration
Through intravenous

25. Applications
• Tetrofosmin is a diagnostic agent used to assess areas of
reversible myocardial ischemia in the presence or absence of
infracted myocardium and is also used to assess ventricular
function.
• It is also indicated to detect changes in perfusion induced by
pharmacologic stress (adenosine, lexiscan, dobutamine or
persantine) in patients with coronary artery disease.

26. Action of Tetrofosmin
• Tc-99m tetrofosmin is rapidly taken up by myocardial
tissue and reaches its maximum level in approximately
5 minutes.

27. Anterior (a) and left lateral (b) projections of the thorax, demonstrated intense Tc-
99m tetrofosmin uptake in the left paracardiac area (arrows).

28. Excretion of Tetrofosmin
• About 66% of the total injected dose is excreted within 48 hours after
injection (40% urine, 26% feces).
• Patients should be encouraged to void their bladders as soon as the
images are gathered, and as often as possible after the tests to
decrease their radiation doses, since the majority of elimination is
renal.

29. References
• www.drugs.com
• Cardiolite kit for preparation of technetium for injection
• The roll of technetium sestamibi in the early detection of breast
carcinoma - Leonard R. Coover ,M D
• Basic Science for Nuclear Medicine
• www.wikipedia.com

30. Thank You