The non-invasive nature of this technology makes it a powerful diagnostic tool to help diagnose certain diseases and conditions.
The gamma rays emitted by the radioisotope are received by a scanner as the drug passes through the body, this information is then used by a nuclear medicine technologist to create a 3D image of the hepatobiliary system.
The amount of radiopharmaceutical given will be just enough to provide sufficient information before the radioisotope decays. The amount of radiation the patient receives is medically insignificant and the patient should suffer no discomfort during treatment.
There is a small risk that patients may experience side effects which are not listed above. It is important that patients report any suspected side effects of Technetium Tc 99m Disofenin to their doctor immediately. Suspected side effects should also be reported to the Food & Drug Administration (FDA) at 1-800-FDA-1088.
Technetium Tc 99m Disofenin should only be administered by a physician or technician registered with the Nuclear Regulatory Commission (NRC). This ensures they have the required training to administer radiopharmaceutical agents safely.
The recommended dosage for Technetium Tc 99m Disofenin in an average sized patient (70 kg) is:
Patients with serum bilirubin levels greater than 5mg/dL: 111-296 MBq (3-8 mCi)
The patient's dosage should be measured by a suitable radioactivity calibration system prior to administration. Slow injection is recommended. (Do not backflush the syringe). Radiochemical purity should also be checked prior to administration.
Usually, only one dose is required for each preparation of Disofenin. However, if a second dose is required it should be administered at least 24 hours after the original dose.
The vial should be visually inspected for particulate matter and discoloration before administration.
There are no known major or moderate drug interactions with Disofenin, however, this does not mean that no drug interactions exist. Therefore patients should always reveal any medication they may be taking, both prescribed and over the counter, to their doctor before administration. If the patient is taking non-prescription drugs, the ingredients should be examined carefully.
It is also recommended that radiopharmaceutical medicines should not be taken while eating food, consuming alcohol or using tobacco. The administering doctor should provide patients with instructions prior to administration, these should be adhered to or test results may be affected. Patients should notify their doctor if they have consumed food or alcohol in the four hours prior to administration.
Before administering Disofenin doctors should take into account the patient's full medical history. Disofenin is a relatively safe drug when administered correctly but certain conditions may decrease its effectiveness. Doctors must weigh up the potential benefits of taking the drug against any possible risks involved.
Allergies – Patients who have suffered an allergic reaction to any drug, including anesthetic, should notify their doctor prior to the administration of Disofenin. Patients should also tell their doctor if they suffer from any other type of allergy including; food allergies, dyes, preservatives, or animal allergies.
Pediatrics – No specific studies have been carried out on the potential effects of Technetium Tc 99m Disofenin on the pediatric population. Because safety and efficacy have not been established, it is NOT recommended the drug be administered to children.
Geriatrics – No specific studies have been carried out on the potential effects of Technetium Tc 99m Disofenin on the geriatric population. However, geriatric-specific problems are not thought to limit the effectiveness of the drug. It should be noted that such patients are more likely to suffer from age-related kidney, liver and heart problems. In this case, the administering doctor may want to reduce the dosage.
Pregnancy – Appropriate studies in pregnant women have not been carried out, however, studies have shown that Tc 99m crosses the placenta during pregnancy. Therefore caution is recommended before administering the drug during pregnancy. If a diagnostic procedure is deemed necessary for the health of the patient, the dosage can be modified to decrease the risk of fetal damage. But it is advised that any elective diagnostic procedures are postponed until after pregnancy.
Breastfeeding – Early studies in women who are breastfeeding have demonstrated that the drug is passed into breast milk and may cause harmful effects to infants. However, the United States Nuclear Regulatory Commission recommends that Technetium Tc 99m Disofenin can be administered in doses up to 1000 MBq (30 mCi) without interrupting breastfeeding.
The International Commission on Radiological Protection also recommends that breastfeeding can continue immediately after the administration of Technetium Tc 99m Disofenin. However, nursing mothers are advised to follow the principle of keeping exposure as low as reasonably possible, by waiting three to six hours after the dose before resuming breastfeeding.
The following diseases and conditions may cause nonvisualization or delayed visualization of the gallbladder:
Patients with chronic cholecystitis, pancreatitis, hepatocellular disease, juvenile hepatitis or sepsis may show absent or delayed hepatobiliary clearance. A positive finding in such cases does not, by itself, permit a differential diagnosis. Doctors should, therefore, consider the results in conjunction with the overall clinical picture, including the results of other diagnostic modalities.
Patients are also advised to fast for up to four hours before the administration of Technetium Tc 99m Disofenin. The ingestion of a meal may provide false-positive results due to gallbladder contraction stimulated by meal ingestion.
Technetium Tc 99m Disofenin is a radiopharmaceutical agent which requires careful handling and disposal. Only physicians or pharmaceutical technicians with the appropriate Nuclear Regulatory Commission (NRC) registration should handle or prepare the drug for medical use.
The drug should be stored in the original lead container or a third party container with adequate radiation shielding. The product should be stored at room temperature 20°C to 25°C (68°F to 77°F) and protected from direct sunlight.
Warning: The reconstituted product should be used within six hours of preparation.
Note: Caution–Radioactive material.
Technetium Tc 99m Disofenin is a radiopharmaceutical agent which is used for to carry out cholescintigraphy, (examination of the gallbladder and bile ducts by nuclear medicine scanning). The medicine emits gamma rays which are detected by special imaging equipment. This equipment is then used to build a 3D model of the hepatobiliary system, allowing doctors to view the functioning of the hepatobiliary system without resorting to invasive surgery.
Radiopharmaceutical agents are perfectly safe if they are administered at the recommended dosage. The amount of radiation the patient is exposed to is relatively small, less than the radiation received from an x-ray for example. During the procedure the patient usually suffers no adverse side effects. Once the treatment is over the radiopharmaceutical passes through the body or is absorbed by internal organs without leaving any trace.
Technetium Tc 99m Disofenin must be stored in a controlled environment and administered by a physician or technician who is registered by the U.S. Nuclear Regulatory Commission (NRC). This ensures the administering physician is properly qualified to handle radioactive materials and have the required medical training to ensure safe administration of radiopharmaceuticals. Technetium Tc 99m Disofenin must NOT be self-administered or administered by a medical professional without the required nuclear medicine training.
The risk of side effects with Technetium Tc 99m Disofenin is quite small, in tests only a tiny percentage of subjects reported any adverse effects. However, there are a number of pre-existing conditions, such as pancreatitis, which may inhibit the effectiveness of the drug. Doctors must, therefore, carry out a thorough check of the patient's medical history before administering Technetium Tc 99m Disofenin.
Extra care should also be taken with patients of childbearing age. While the drug can still be administered during pregnancy, it should only be administered if the benefit is deemed to outweigh the risk of radiation exposure to the fetus. In most cases, it is safer to wait until after the birth of the child before administration. Patients who are breastfeeding are advised to feed before treatment and to not resume feeding until at least three and preferably six hours after treatment has finished.