Radiopharmaceuticals

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RADIOPHARMACEUTICAL
Definition
Radiopharmaceuticals are radioactive substances that may be used to treat cancer.
Purpose
The common radiopharmaceuticals that are used in cancer treatment include:
Chromic phosphate P 32 for the treatment of lung, ovarian, uterine, and prostate cancers
Sodium iodide I 131 for treating certain types of thyroid cancer
Strontium chloride Sr 89 for treating cancerous bone tissue
Samarium Sm 153 lexidronam for treating cancerous bone tissue
Sodium phosphate P 32 for treating cancerous bone tissue and other types of cancers.
Description
Radiopharmaceuticals used in cancer treatment are small, simple substances, containing a radioactive isotope or form of an element. They are targeted to specific areas of the body where cancer is present. Radiation emitted from the isotope kills cancer cells. These isotopes have short half-lives, meaning that most of the radiation is gone within a few days or weeks.
Chromic Phosphate P 32 and Sodium Iodide I 131
Chromic phosphate P 32 is a salt of chromium and phosphoric acid, containing a radioactive form of the element phosphorous, 32P. Its brand name is Phosphocol P 32. Chromic phosphate P 32 is used to treat fluid accumulations that can result from lung, ovarian, or uterine cancers. It is 50-80% effective in stopping fluid leakage from these organs. Chromic phosphate P 32 also is used to kill cancer cells that remain following surgery for uterine cancer. It may be used to treat ovarian or prostate cancers directly. The use of chromic phosphate P 32 is not combined with external beam radiation, but may be used in conjunction with chemotherapy.
Sodium iodide I 131, also called radioactive iodine or radioiodide, is a salt of sodium and a radioactive form of the element iodine, 131I. Sodium iodide I 131 is taken up by the thyroid gland, which absorbs most of the iodine in the body. Sodium iodide I 131 can destroy the thyroid gland, with only minor effects on other parts of the body. It is used following surgery for thyroid cancer to destroy any remaining cancerous thyroid tissue, or to destroy thyroid cancer that has spread (metastasized) to lymph nodes or other tissues. Sodium iodide I 131 is a standard treatment for differentiated thyroid cancer that has spread to the neck and other parts of the body. Its use improves the survival rate for such patients. It is not clear whether radioiodide is beneficial for small cancers of the thyroid that have not metastasized to other tissues.
Bone Metastasis
Several radiopharmaceuticals are used to treat cancerous tissue in the bone, particularly from prostate cancer. Most prostate cancer metastasizes to the bone and often this is the cause of death. When injected into a vein these radiopharmaceuticals accumulate in cancerous bone tissue and give off radiation that kills cancer cells and relieves pain in the majority of patients. These treatments are most effective for cancer that has metastasized to multiple bones. Sometimes these radiopharmaceuticals are used in conjunction with external beam radiation that is directed at the most painful areas.
Strontium chloride Sr 89 (strontium-89) is the most common radiopharmaceutical for treating bone cancer or prostate cancer that has metastasized to the bone. It is a salt of chlorine and a radioactive isotope of strontium, 89Sr. Its brand name is Metastron. Men with advanced prostate cancer who are responding to chemotherapy appear to have a better chance of survival if bone metastases is treated with strontium-89 every six weeks in conjunction with a chemotherapy drug.
Samarium SM 153 lexidronam is a radioactive form of samarium, 153Sm. The element is inside a small molecule called lexidronam. The brand name for samarium SM 153 lexidronam is Quadramet. It is used primarily to treat prostate cancer that has metastasized to the bone.
Sodium phosphate P 32 is a salt of sodium and phosphoric acid containing a radioactive form of the element phosphorous, 32P. It is used primarily for breast and prostate cancers that have metastasized to the bone. It also may be used to treat other types of cancer.
Two other radioactive isotopes, rhenium 86 and rhenium 188, sometimes are used to treat bone metastasis from prostate cancer.
Recommended Dosage
Dosages of radiopharmaceuticals vary with the individual and the type of treatment. Dosages of radioactive materials are expressed in units called millicuries.
Chromic phosphate P 32 is a suspension that is delivered through a catheter, or tube, inserted into the sac surrounding the lungs, or into the abdominal or pelvic cavities. The usual dosage is 15-20 millicuries for abdominal administration and 10 millicuries for administration to the lung sac. Chromic phosphate P 32 also may be injected into the ovaries or prostate.
Sodium Iodide I 131 is taken by mouth as a capsule or a solution. The usual dose for treating thyroid cancer is 30-200 millicuries, depending on age and body size. Doses may be repeated. Treatment usually requires two to three days of hospitalization. For this therapy to be effective there must be high levels of thyroid-stimulating hormone (TSH, or thyrotropin) in the blood. This hormone can be injected prior to treatment.
Strontium-89 is injected into a vein. The usual dosage is 4 millicuries, depending on age, body size, and blood cell counts. Repeated doses may be required.
The usual dosage of samarium Sm 153 lexidronam is 1 millicurie per kg (0.45 millicurie per lb) of body weight, injected slowly into a vein. Repeated doses may be necessary. Because samarium Sm 153 lexidronam may accumulate in the bladder, it is important to drink plenty of liquid prior to treatment and to urinate often after treatment. This reduces the irradiation of the bladder.
The dosage of sodium phosphate P 32 depends on age, body size, blood cell counts, and the type of treatment. The usual dosages range from 1–5 millicuries. Repeated doses may be required.
Precautions
Some individuals may have an allergic reaction to strontium-89, samarium SM 153 lexidronam, or sodium phosphate P 32.
Radiopharmaceuticals usually are not recommended for use during pregnancy. It is recommended that women do not become pregnant for a year after treatment with sodium iodide I 131. Breast-feeding is not possible during treatment with radiopharmaceuticals.
Precautions Before Treatment With Sodium Iodide I 131
Foods containing iodine, such as iodized salt, seafoods, cabbage, kale, or turnips, should be avoided for several weeks prior to treatment with sodium iodide I 131. The iodine in these foods will be taken up by the thyroid, thereby reducing the amount of radioiodide that can be taken up. Radiopaque agents containing iodine sometimes are used to improve imaging on an x ray. A recent x-ray exam that included such an agent may interfere with the ability of the thyroid to take up radioiodide.
Diarrhea or vomiting may cause sodium iodide I 131 to be lost from the body, resulting in less effective treatment and the risk of outside contamination. Kidney disease may prevent the excretion of radioiodide, increasing the risk of side effects from the drug.
Precautions After Treatment With Radiopharmaceuticals
Strontium-89, samarium Sm 153 lexidronam, and large total doses of sodium iodide I 131 may temporarily lower the number of white blood cells, which are necessary for fighting infections. The number of blood platelets (important for blood clotting) also may be lowered. Precautions for reducing the risk of infection and bleeding include:
avoiding people with infections
seeking medical help at the first sign of infection or unusual bleeding
using care when cleaning teeth
avoiding touching the eyes or inside of the nose
avoiding cuts and injuries
It is important to drink plenty of liquids and to urinate often after treatment with sodium iodide I 131. This flushes the radioiodide from the body. To reduce the risk of contaminating the environment or other people, the following procedures should be followed for 48–96 hours after treatment is sodium iodide I 131:
avoiding kissing and sex
avoiding the handling of another person's eating utensils, etc.
avoiding close contact with others, especially pregnant women
washing the tub and sink after each use
washing hands after using or cleaning the toilet
using separate washcloths and towels
washing clothes, bed linens, and dishes separately
flushing the toilet twice after each use
Strontium-89 and samarium Sm 153 lexidronam also are excreted in the urine. To prevent radioactive contamination, special measures should be followed for one week after receiving strontium-89 and for 12 hours after receiving samarium Sm 153 lexidronam:
using a toilet rather than a urinal
flushing the toilet several times after each use
wiping up and flushing any spilled urine or blood
washing hands after using or cleaning a toilet
washing soiled clothes and bed linens separately from other laundry.
Individuals with bladder control problems must take special measures following treatment to prevent contamination with radioactive urine.
Side Effects
The more common side effects of chromic phosphate P 32 may include:
loss of appetite (anorexia)
abdominal cramps
diarrhea
nausea and vomiting
weakness or fatigue
Less common but serious side effects of chromic phosphate P 32 may include:
severe abdominal pain
severe nausea and vomiting
fever
chills
dry cough
sore throat
chest pain
difficulty breathing
bleeding or bruising
Side effects of treatment with sodium iodide I 131 are rare and temporary. However, they may include:
loss of taste
dry mouth (xerostomia)
stomach irritation
nausea and vomiting
tenderness in the salivary glands or neck
Large total doses of radioiodine may cause infertility in men.
Flushing and transient increased bone pain are among the more common side effects of strontium-89.
Less common side effects of samarium Sm 153 lexidronam include:
irregular heartbeat
temporary increase in bone pain
nausea and vomiting
Signs of infection due to low white blood cell counts after treatment with strontium-89, samarium Sm 153 lexidronam, or sodium iodide I 131 include:
fever or chills
cough or hoarseness
lower back or side pain
painful or difficult urination
Signs of low platelet count after treatment with strontium-89, samarium Sm 153 lexidronam, or sodium iodide I 131 include:
bleeding or bruising
black, tar-like stools
blood in urine or stools
tiny red spots on the skin
Side effects are rare with sodium phosphate P 32. However, for patients treated with sodium phosphate P 32 for bone pain, side effects may include:
diarrhea
fever
nausea and vomiting
Anemia (low red blood cell count) or a decrease in the white blood cell count also are possible.
Since children and older adults are particularly sensitive to radiation, they may experience more side effects during and after treatment with radiopharmaceuticals.
Interactions
Radiation therapy or anticancer drugs may increase the harmful effects of strontium-89 and samarium SM 153 lexidronam on the bone marrow. Medicines containing calcium may prevent strontium-89 from being taken up by bone tissue. Etidronate (Didronel, one of the socalled bisphosphonates that may be used to prevent or treat osteoporosis) may prevent samarium Sm 153 lexidronam from working effectively.
http://www.mayoclinic.com/health/drug-information/DR602307

RADIOPHARMACEUTICAL
Description
Radiopharmaceuticals are agents used to diagnose certain medical problems or treat certain diseases. They may be given to the patient in several different ways. For example, they may be given by mouth, given by injection, or placed into the eye or into the bladder.
These radiopharmaceuticals are used in the diagnosis of:
Abscess and infection—Gallium Citrate Ga 67, Indium In 111 Oxyquinoline
Biliary tract blockage—Technetium Tc 99m Disofenin, Technetium Tc 99m Lidofenin, Technetium Tc 99m Mebrofenin
Blood volume studies—Radioiodinated Albumin, Sodium Chromate Cr 51
Blood vessel diseases—Sodium Pertechnetate Tc 99m
Blood vessel diseases of the brain—Ammonia N 13, Iofetamine I 123, Technetium Tc 99m Bicisate, Technetium Tc 99m Exametazime, Xenon Xe 133
Bone diseases—Sodium Fluoride F 18, Technetium Tc 99m Medronate, Technetium Tc 99m Oxidronate, Technetium Tc 99m Pyrophosphate, Technetium Tc 99m (Pyro- and trimeta-) Phosphates
Bone marrow diseases—Sodium Chromate Cr 51, Technetium Tc 99m Albumin Colloid, Technetium Tc 99m Sulfur Colloid
Brain diseases and tumors—Fludeoxyglucose F 18, Indium In 111 Pentetreotide, Iofetamine I 123, Sodium Pertechnetate Tc 99m, Technetium Tc 99m Exametazime, Technetium Tc 99m Gluceptate, Technetium Tc 99m Pentetate
Cancer; tumors—Fludeoxyglucose F 18, Gallium Citrate Ga 67, Indium In 111 Pentetreotide, Methionine C 11, Radioiodinated Iobenguane, Sodium Fluoride F 18, Technetium Tc 99m Arcitumomab, Technetium Tc 99m Nofetumomab Merpentan
Colorectal disease—Technetium Tc 99m Arcitumomab
Disorders of iron metabolism and absorption—Ferrous Citrate Fe 59
Heart disease—Ammonia N 13, Fludeoxyglucose F 18, Rubidium Rb 82, Sodium Pertechnetate Tc 99m, Technetium Tc 99m Albumin, Technetium Tc 99m Sestamibi, Technetium Tc 99m Teboroxime, Technetium Tc 99m Tetrofosmin, Thallous Chloride Tl 201
Heart muscle damage (infarct)—Ammonia N 13, Fludeoxyglucose F 18, Rubidium Rb 82, Technetium Tc 99m Pyrophosphate, Technetium Tc 99m (Pyro- and trimeta-) Phosphates, Technetium Tc 99m Sestamibi, Technetium Tc 99m Teboroxime, Technetium Tc 99m Tetrofosmin, Thallous Chloride Tl 201
Impaired flow of cerebrospinal fluid in brain—Indium In 111 Pentetate
Kidney diseases—Iodohippurate Sodium I 123, Iodohippurate Sodium I 131, Iothalamate Sodium I 125, Technetium Tc 99m Gluceptate, Technetium Tc 99m Mertiatide, Technetium Tc 99m Pentetate, Technetium Tc 99m Succimer
Liver diseases—Ammonia N 13, Fludeoxyglucose F 18, Technetium Tc 99m Albumin Colloid, Technetium Tc 99m Disofenin, Technetium Tc 99m Lidofenin, Technetium Tc 99m Mebrofenin, Technetium Tc 99m Sulfur Colloid
Lung diseases—Krypton Kr 81m, Technetium Tc 99m Albumin Aggregated, Technetium Tc 99m Pentetate, Xenon Xe 127, Xenon Xe 133
Parathyroid diseases; parathyroid cancer—Technetium Tc 99m Sestamibi, Thallous Chloride Tl 201
Pernicious anemia; improper absorption of vitamin B12 from intestines—Cyanocobalamin Co 57
Red blood cell diseases—Sodium Chromate Cr 51
Salivary gland diseases—Sodium Pertechnetate Tc 99m
Spleen diseases—Sodium Chromate Cr 51, Technetium Tc 99m Albumin Colloid, Technetium Tc 99m Sulfur Colloid
Stomach and intestinal bleeding—Sodium Chromate Cr 51, Sodium Pertechnetate Tc 99m, Technetium Tc 99m (Pyro- and trimeta-) Phosphates, Technetium Tc 99m Sulfur Colloid
Stomach problems—Technetium Tc 99m Sulfur Colloid
Tear duct blockage—Sodium Pertechnetate Tc 99m
Thyroid diseases; thyroid cancer—Fludeoxyglucose F 18, Indium In 111 Pentetreotide, Radioiodinated Iobenguane, Sodium Iodide I 123, Sodium Iodide I 131, Sodium Pertechnetate Tc 99m, Technetium Tc 99m Sestamibi
Urinary bladder diseases—Sodium Pertechnetate Tc 99m
Radiopharmaceuticals are radioactive agents. However, when small amounts are used, the radiation your body receives from them is very low and is considered safe. When larger amounts of these agents are given to treat disease, there may be different effects on the body.
When radiopharmaceuticals are used to help diagnose medical problems, only small amounts are given to the patient. The radiopharmaceutical then passes through, or is taken up by, an organ of the body (which organ depends on what radiopharmaceutical is used and how it has been given). Then the radioactivity is detected, and pictures are produced, by special imaging equipment. These pictures allow the nuclear medicine doctor to study how the organ is working and to detect cancer or tumors that may be present in the organ.
Some radiopharmaceuticals are used in larger amounts to treat certain kinds of cancer and other diseases. In those cases, the radioactive agent is taken up in the cancerous area and destroys the affected tissue. The information that follows applies only to radiopharmaceuticals when used in small amounts to diagnose medical problems.
The dosages of radiopharmaceuticals that are used to diagnose medical problems will be different for different patients and depend on the type of test. The amount of radioactivity of a radiopharmaceutical is expressed in units called becquerels or curies. Radiopharmaceutical dosages given may be as small as 0.185 megabecquerels (5 microcuries) or as high as 1295 megabecquerels (35 millicuries). The radiation received from these dosages may be about the same as, or even less than, the radiation received from an x-ray study of the same organ.
Radiopharmaceuticals are to be given only by or under the direct supervision of a doctor with specialized training in nuclear medicine.
OncoScint(R) CR/CV (satumomab pendetide) was discontinued in the United States on December 26, 2002.
Marketing of NeutroSpec (technetium 99m TC fanolesomab) was discontinued by Palatin Technologies, their marketing partner, Mallinckrodt, and the FDA. The risk of severe and fatal allergic-type reactions outweigh its benefit.
This product is available in the following dosage forms:
Capsule
Kit
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Before Using
In deciding to receive a diagnostic test, the risks of taking the test must be weighed against the good it will do. This is a decision you and your doctor will make. For these tests, the following should be considered:
Allergies
Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Pediatric
For most radiopharmaceuticals, the amount of radiation used for a diagnostic test is very low and considered safe. However, be sure you have discussed with your doctor the benefit versus the risk of exposing your child to radiation.
Geriatric
Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. Although there is no specific information comparing use of most radiopharmaceuticals in the elderly with use in other age groups, problems would not be expected to occur. However, it is a good idea to check with your doctor if you notice any unusual effects after receiving a radiopharmaceutical.
Pregnancy
Radiopharmaceuticals usually are not recommended for use during pregnancy. This is to avoid exposing the fetus to radiation. Some radiopharmaceuticals may be used for diagnostic tests in pregnant women, but it is necessary to inform your doctor if you are pregnant so the doctor may reduce the radiation dose to the baby. This is especially important with radiopharmaceuticals that contain radioactive iodine, which can go to the baby's thyroid gland and, in high enough amounts, may cause thyroid damage. Be sure you have discussed this with your doctor.
Breastfeeding
Some radiopharmaceuticals pass into the breast milk and may expose the baby to radiation. If you must receive a radiopharmaceutical, it may be necessary for you to stop breast-feeding for some time after receiving it. Be sure you have discussed this with your doctor.
Drug Interactions
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.
Other Interactions
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
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Proper Use
The nuclear medicine doctor may have special instructions for you in preparation for your test. For example, before some tests you must fast for several hours, or the results of the test may be affected. For other tests you should drink plenty of liquids. If you do not understand the instructions you receive or if you have not received any instructions, check with the nuclear medicine doctor in advance.
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Precautions
There are usually no special precautions to observe for radiopharmaceuticals when they are used in small amounts for diagnosis.
Some radiopharmaceuticals may accumulate in your bladder. Therefore, to increase the flow of urine and lessen the amount of radiation to your bladder, your doctor may instruct you to drink plenty of liquids and urinate often after certain tests.
For patients receiving radioactive iodine (iodohippurate sodium I 123, iodohippurate sodium I 131, iofetamine I 123, iothalamate I 125, radioiodinated albumin, or radioiodinated iobenguane):
Make sure your doctor knows if you are planning to have any future thyroid tests. Even after several weeks, the results of the thyroid test may be affected by the iodine solution that may be given before the radiopharmaceutical.
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Side Effects
Along with its needed effects, a medicine may cause some unwanted effects. When radiopharmaceuticals are used in very small doses to study an organ of the body, side effects are rare and usually involve an allergic reaction. These effects may occur almost immediately or a few minutes after the radiopharmaceutical is given. It may be helpful to note the time when you first notice any side effect. Your doctor, nuclear medicine physician and/or technologist, or nurse will be prepared to give you immediate medical attention if needed.
Check with your doctor or nurse immediately if any of the following side effects occur:
Rare
Chills
Difficulty breathing
Drowsiness (severe)
Fainting
Fast heartbeat
Fever
Flushing or redness of skin
Headache (severe)
Nausea or vomiting
Skin rash, hives, or itching
Stomach pain
Swelling of throat, hands, or feet
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.