gallium scan


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Related to gallium scan: Gallium Scan of the Body

gallium scan

a nuclear scan of the total body performed after an IV injection of radioactive gallium, a radionuclide that concentrates in areas of inflammation and infection, abscess, and benign and malignant tumor. It is useful in detecting metastatic tumor, especially lymphoma.

gallium scan

Nuclear medicine A radioscintillation imaging method in which 67gallium citrate–T1/2, 25 days, is injected IV, and images of its pattern of distribution are obtained; GS is used to stage lymphoma, lung CA, hepatoma, melanoma, metastases–to bone, brain, lung, head & neck, GI and genitourinary neoplasia

gallium scan

A method of demonstrating tumours and inflammation in the liver and elsewhere. Gallium is an element that concentrates in tumour and inflammatory cells to a greater extent than in normal liver cells. The radioactive isotope, gallium-67, which is chemically identical, can therefore be used in conjunction with a GAMMA CAMERA to reveal liver cancers or areas of inflammation.

Gallium Scan

Synonym/acronym: Ga scan.

Common use

To assist in diagnosing, evaluating, and staging tumors and in detecting areas of infection, inflammation, and abscess.

Area of application

Whole body.

Contrast

IV radioactive gallium-67 citrate.

Description

Gallium imaging is a nuclear medicine study that assists in diagnosing neoplasm and inflammation activity. Gallium, which has 90% sensitivity for inflammatory disease, is readily distributed throughout plasma and body tissues. Gallium imaging is sensitive in detecting abscesses, pneumonia, pyelonephritis, active sarcoidosis, and active tuberculosis. In immunocompromised patients, such as patients with AIDS, gallium imaging can detect complications such as Pneumocystis jiroveci (formerly P. carinii) pneumonitis. Gallium imaging is useful but less commonly performed in the diagnosis and staging of some neoplasms, including Hodgkin’s disease, lymphoma, melanoma, and leukemia. Imaging can be performed 6 to 72 hr after injection of the gallium and a gamma camera detects the radiation emitted from the injected radioactive material. A representative image of the distribution of the radioactive material is then obtained. Single-photon emission computed tomography (SPECT) has significantly improved the resolution and accuracy of gallium scanning and may or may not be included as part of the examination. SPECT enables images to be recorded from multiple angles around the body and reconstructs them by a computer to produce images or “slices” representing the area of interest at different levels. Generally, the nonspecificity of gallium imaging requires correlation with other diagnostic studies, such as computed tomography, CT/PET, magnetic resonance imaging, and ultrasonography.

This procedure is contraindicated for

  • high alert Patients who are pregnant or suspected of being pregnant, unless the potential benefits of a procedure using radiation far outweigh the risk of radiation exposure to the fetus and mother.

Indications

  • Aid in the diagnosis of infectious or inflammatory diseases
  • Evaluate lymphomas
  • Evaluate recurrent lymphomas or tumors after radiation therapy or chemotherapy
  • Perform as a screening examination for fever of undetermined origin

Potential diagnosis

Normal findings

  • Normal distribution of gallium; some localization of the radionuclide within the liver, spleen, bone, nasopharynx, lacrimal glands, breast, and bowel is expected

Abnormal findings related to

  • Abscess
  • Infection
  • Inflammation
  • Lymphoma
  • Tumor

Critical findings

    N/A

Interfering factors

  • Factors that may impair clear imaging

    • Inability of the patient to cooperate or remain still during the procedure because of age, significant pain, or mental status.
    • Metallic objects (e.g., jewelry, body rings) within the examination field, which may inhibit organ visualization and cause unclear images.
    • Performance of other nuclear scans within the preceding 24 to 48 hr.
    • Administration of certain medications (e.g., gastrin, cholecystokinin), which may interfere with gastric emptying.
  • Other considerations

    • Improper injection of the radionuclide may allow the tracer to seep deep into the muscle tissue, producing erroneous hot spots.
    • Consultation with a health-care provider (HCP) should occur before the procedure for radiation safety concerns regarding younger patients or patients who are lactating. Pediatric & Geriatric Imaging Children and geriatric patients are at risk for receiving a higher radiation dose than necessary if settings are not adjusted for their small size. Pediatric Imaging Information on the Image Gently Campaign can be found at the Alliance for Radiation Safety in Pediatric Imaging (www.pedrad.org/associations/5364/ig/).
    • Risks associated with radiation overexposure can result from frequent x-ray or radionuclide procedures. Personnel working in the examination area should wear badges to record their level of radiation.

Nursing Implications and Procedure

Pretest

  • Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching: Inform the patient this procedure can assist in identifying infection or other disease.
  • Obtain a history of the patient’s complaints or clinical symptoms, including a list of known allergens, especially allergies or sensitivities to latex, anesthetics, sedatives, or radionuclides.
  • Obtain a history of the patient’s immune system, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
  • Note any recent procedures that can interfere with test results, including examinations using iodine-based contrast medium.
  • Record the date of the last menstrual period and determine the possibility of pregnancy in perimenopausal women.
  • Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
  • Review the procedure with the patient. Address concerns about pain related to the procedure and explain that some pain may be experienced during the test, or there may be moments of discomfort. Reassure the patient that the radionuclide poses no radioactive hazard and rarely produces side effects. Inform the patient that the procedure is performed in a nuclear medicine department by an HCP specializing in this procedure, with support staff, and takes approximately 60 min. Pediatric Considerations Preparing children for a gallium scan depends on the age of the child. Encourage parents to be truthful about what the child may experience during the procedure (e.g., the child may feel a pinch or minor discomfort when the IV needle is inserted) and to use words that they know their child will understand. Toddlers and preschool-age children have a very short attention span, so the best time to talk about the test is right before the procedure. The child should be assured that he or she will be allowed to bring a favorite comfort item into the examination room, and if appropriate, that a parent will be with the child during the procedure. Explain the importance of remaining still while the images are taken.
  • Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Explain that an IV line may be inserted to allow infusion of IV fluids such as normal saline, anesthetics, sedatives, radionuclides, medications used in the procedure, or emergency medications.
  • Instruct the patient to remove jewelry and other metallic objects from the area to be examined.
  • Note that there are no food, fluid, or medication restrictions unless by medical direction.
  • Make sure a written and informed consent has been signed prior to the procedure and before administering any medications.

Intratest

  • Potential complications:
  • Although it is rare, there is the possibility of allergic reaction to the radionuclide. Have emergency equipment and medications readily available. If the patient has a history of allergic reactions to any substance or drug, administer ordered prophylactic steroids or antihistamines before the procedure.

  • Establishing an IV site and injection of radionuclides is an invasive procedure. Complications are rare but do include bleeding from the puncture site related to a bleeding disorder, or the effects of natural products and medications known to act as blood thinners, hematoma related to blood leakage into the tissue following needle insertion, infection that might occur if bacteria from the skin surface is introduced at the puncture site, or nerve injury that might occur if the needle strikes a nerve.

  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient.
  • Ensure that the patient has removed all external metallic objects from the area to be examined prior to the procedure.
  • Administer ordered prophylactic steroids or antihistamines before the procedure if the patient has a history of allergic reactions to any substance or drug.
  • Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
  • Have emergency equipment readily available.
  • Instruct the patient to void prior to the procedure and to change into the gown, robe, and foot coverings provided.
  • Record baseline vital signs and assess neurological status. Protocols may vary among facilities.
  • Establish an IV fluid line for the injection of saline, anesthetics, sedatives, radionuclides, or emergency medications.
  • Instruct the patient to cooperate fully and to follow directions. Instruct the patient to lie still during the procedure because movement produces unclear images.
  • Administer a sedative to a child or to an uncooperative adult, as ordered.
  • Place the patient in a supine position on a flat table with foam wedges, which help maintain position and immobilization.
  • IV radionuclide is administered, and the patient is instructed to return for scanning at a designated time after injection. Typical scanning occurs at 6, 24, 48, 72, 96, and/or 120 hr postinjection depending on diagnosis.
  • If an abdominal abscess or infection is suspected, laxatives or enemas may be ordered before imaging at 48 or 72 hr after the injection.
  • Monitor the patient for complications related to the procedure (e.g., allergic reaction, anaphylaxis, bronchospasm).
  • The needle or catheter is removed, and a pressure dressing is applied over the puncture site.
  • Observe the needle/catheter insertion site for bleeding, inflammation, or hematoma formation.

Post-Test

  • Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
  • Unless contraindicated, advise the patient to drink increased amounts of fluids for 24 to 48 hr to eliminate the radionuclide from the body. Inform the patient that radionuclide is eliminated from the body within 6 to 24 hr.
  • Instruct the patient to resume usual medication or activity, as directed by the HCP.
  • Instruct the patient in the care and assessment of the injection site.
  • If a woman who is breastfeeding must have a nuclear scan, she should not breastfeed the infant until the radionuclide has been eliminated. This could take as long as 3 days. She should be instructed to express the milk and discard it during the 3-day period to prevent cessation of milk production.
  • Instruct the patient to immediately flush the toilet and to meticulously wash hands with soap and water after each voiding for 24 hr after the procedure.
  • Instruct all caregivers to wear gloves when discarding urine for 48 hr after the procedure. Wash gloved hands with soap and water before removing gloves. Then wash ungloved hands after removing the gloves.
  • Recognize anxiety related to test results, and be supportive of perceived loss of independent function. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate.
  • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
  • Depending on the results of this procedure, additional testing may be needed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.

Related Monographs

  • Related tests include angiotensin converting enzyme, biopsy bone marrow, biopsy kidney, biopsy lung, blood gases, bronchoscopy, CBC, CBC WBC and differential, chest x-ray, CT abdomen, CT pelvis, CT thoracic, culture blood, culture and smear mycobacteria, culture viral, cytology sputum, cytology urine, ESR, HIV-1/2 antibodies, IVP, lung perfusion scan, MRI chest, MRI abdomen, mediastinoscopy, pleural fluid analysis, plethysmography, PFT, pulse oximetry, renogram, US kidney, and US lymph node.
  • Refer to the Immune System table at the end of the book for related tests by body system.

gallium

a chemical element, atomic number 31, atomic weight 69.72, symbol Ga. See Table 6.

gallium-67
a radioisotope of gallium having a half-life of 78.1 hours; used in the imaging of soft tissue tumors.
gallium nitrate
used in the treatment of hypercalcemia.
gallium scan
a nuclear medicine procedure using the radioisotope gallium-67 in the form of gallium citrate. Gallium has a high affinity for certain tumors and also for non-neoplastic lesions, such as abscesses. Gallium scans are particularly useful in the staging of lymphomas, and in localizing occult abscesses.
References in periodicals archive ?
An abnormal gallium scan after an abnormal Tc-99 MDP scan increases the specificity of the diagnosis.
MRI does serve as a valuable guide to the interpretation of technetium and gallium scans, and thus it is extremely useful in the treatment of skull base osteomyelitis.
However, computed tomography (CT), magnetic resonance imaging (MRI), gallium scans, and 2-[F-18]-fluoro-2-deoxy-D-glucose positronemission tomography (FDG-PET) have all come into use, and they provide physiologic as well as anatomic data.
Gallium scans and FDG-PET are especially helpful in assessing these cases.
Additionally, they reported that all four of the treatment failures in their study were evident on gallium scans.