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Fludeoxyglucose F18 is a radioactive tracer that acts as a glucose analog and is used for diagnostic purposes in conjunction with positron-emitting tomography (PET) to localize the tissues with altered glucose metabolism. It does not have therapeutic use. Altered glucose metabolism has implications for malignancies, epilepsy, myocardial ischemia, inflammatory conditions, and Alzheimer disease. PET scan uses radiotracers injected into the patient before the scan to visualize the blood flow and metabolic and biochemical activities in diseased and healthy tissues. FDG is a glucose analog that tends to accumulate in the tissue with high glucose demand, like tumors and inflammatory cells. This activity describes the indications, mechanism of action in various conditions, administration, precautions in the particular patient population, and relevant information to maximize patient and staff safety while obtaining optimal images and analysis. Objectives: Identify the proper administration of fludeoxyglucose (F18). Describe the importance of patient preparation before administering fludeoxyglucose (F18). Explain FDG use in various conditions for diagnostic or treatment monitoring. Discuss interprofessional team strategies for improving care coordination and communication to obtain suboptimal images while maintaining safety. Access free multiple choice questions on this topic.

PET imaging is used for detecting metabolic changes, and a CT scan is useful for detecting anatomical changes. Integrated PET/CT scanners allow the acquisition of both PET and CT in a single visit without moving the patient and are more accurate for localizing lesions. Images from PET and CT can be viewed side by side or fused using the software. Fludeoxyglucose F18 is a radioactive drug and emits radiation. Therefore, the goal of patient preparation, good history, and appropriate precautions when administering FDG is to minimize radiation exposure while obtaining optimal imaging. Patient Preparation Patient preparation is crucial when obtaining PET/CT imaging. [Level 1] When scheduling the patient for the morning study, they should be instructed to have a light meal the evening before with no alcohol and not eat anything after midnight. [Level 5] For afternoon schedules, patients can have a light breakfast before 8 am without sugar-containing food and take their medications as prescribed. [Level 5] Pre-hydrating reduces artifacts and reduces radiation exposure. The patient should drink one liter of water 2 hours before FDG injection to minimize FDG concentration in the bladder. [Level 3] Radioactivity in the bladder and ureters can impair the interpretation of the lesion when assessing small pelvic tumors. Furosemide can be administered but is usually not necessary because of proper pre-hydration.[29] [Level 5] After injecting FDG, the patient should remain still and silent to minimize muscle uptake of FDG. [Level 1] Injections in the darkened and quiet room will minimize brain activity and can prevent FDG uptake in the brain due to increased brain activation. [Level 3] Brown fat can accumulate FDG if the patient is not warm. [Level 4] Instruct the patient not to exercise at least 6 hours before injection, and they should not arrive at the hospital on a bicycle.[29] [Level 5]

After injecting FDG, the patient should remain still and silent to minimize muscle uptake of FDG. [Level 1] Injections in the darkened and quiet room will minimize brain activity and can prevent FDG uptake in the brain due to increased brain activation. [Level 3] Brown fat can accumulate FDG if the patient is not warm. [Level 4] Instruct the patient not to exercise at least 6 hours before injection, and they should not arrive at the hospital on a bicycle.[29] [Level 5] For patients with diabetes, schedule their PET study in the late afternoon. [Level 5] They also should follow the same fasting rules as mentioned above and continue to take their medications. [Level 1] The triage nurse can check the blood glucose levels when the patient arrives at the imaging center. That way, the patient would not have to wait if their sugar is too high or too low for imaging. [Level 5] Blood glucose level is obtained before administering FDG using a calibrated glucometer.[30] [Level 4] FDG PET can be performed if glucose is < 120 mg/dL and must be rescheduled if > 120 mg/dL depending on the patient circumstances. For tumor imaging, Clinicians should not give insulin to lower blood glucose within 4 hours of administering FDG because it causes FDG uptake in muscles.[29] [Level 1] For cardiology imaging, oral glucose loading followed by supplemental insulin promotes maximum uptake of FDG by healthy myocardium allowing better image quality.[16] [Level 5] According to the American Society of Nuclear Cardiology(ANMC) and European Association of Nuclear Medicine(EANM) joint guidelines for vasculitis, it is essential to withdraw or defer glucocorticoids unless there is a risk of ischemic complications, as in the case of giant cell arteritis with temporal artery involvement. FDG-PET within three days after the start of glucocorticoids is a viable alternative.[31] [Level 3] When ordering a PET/CT Study for Oncology, the following data will assist in coordination and image analysis [Level 5] [29] Indications for ordering PET or PET/CT study Patient's height and weight for calculating standardized uptake values (SUV) Weight can change rapidly during the disease course. Therefore, measure weight instantly before each PET study when obtaining serial studies in the same patient. Tumor type and site (if known) Previous history of tumors and relevant comorbidity (especially inflammation)

Patient's height and weight for calculating standardized uptake values (SUV) Weight can change rapidly during the disease course. Therefore, measure weight instantly before each PET study when obtaining serial studies in the same patient. Tumor type and site (if known) Previous history of tumors and relevant comorbidity (especially inflammation) Results of other imaging studies like CT and MRI Allergies Diabetes mellitus and medications If monitoring change from therapy, provide the date, and type of last treatment Kidney function Required Materials for Properly Administering FDG A triple-channel system permits the tracer administration and flushing with normal saline. Patients may need other lines to obtain the same results using electronic bedside pumps.[29] Bedside glucose meter. It is necessary to check serum glucose in patients susceptible to hyperglycemia. However, bedside glucose meters are not precise enough for SUV correction. If rescheduling a hyperglycemic patient is not feasible, SUV correction is necessary by measuring blood glucose levels using calibrated and validated methods during all sequential PET examinations.[32] [Level 1] Accredited weighing scales Clinical Information for the Scan and its Interpretation Relevant clinical data includes history focused on the disease and location, diagnosis date, verification of diagnosis through biopsy, previous therapies, medications, and imaging results.[29] Comorbidities that are relevant such as diabetes and concurrent inflammation disease Clinicians should obtain a thorough history of prior treatment, including steroids, surgeries, radiation, chemotherapy, and bone marrow stimulants. The minimum interval between the PET imaging and chemotherapy should be about ten days and as close to the next chemotherapy as possible. The date at which the results must be available The ability of the patient to stay still for 20 to 45 minutes and the ability to put their arms over the head History of claustrophobia Preparation and Administration Staff working at the facility should have undergone competency-based training for handling radiopharmaceuticals. These include dose dispensing, calibration, labeling, quality control procedures, radiation safety, record keeping, and aseptic procedures. When handling the drug, use waterproof gloves and effective radiation shielding to avoid unnecessary exposure to the clinical personnel, workers, and the patient.

Staff working at the facility should have undergone competency-based training for handling radiopharmaceuticals. These include dose dispensing, calibration, labeling, quality control procedures, radiation safety, record keeping, and aseptic procedures. When handling the drug, use waterproof gloves and effective radiation shielding to avoid unnecessary exposure to the clinical personnel, workers, and the patient. An indwelling intravenous line is placed after drawing the blood samples for the lab if needed for manual administration. Using the three-way valve, flush and rinse the administration syringe with normal saline. For automated administration, ensure that the administered FDG activity is within 3% of the dose calibrator. Ask the patient to lie or sit comfortably and quietly. Ask them to use the void 30 minutes after administration and 5 minutes before imaging.[29] According to The Society of Nuclear Medicine and Molecular Imaging (SNMMI), interprofessional collaboration is required among healthcare providers. A nuclear medicine physician is preferred to supervise the performance of PET/CT imaging. However, a board-certified pediatric or diagnostic radiologist with the required additional nuclear medicine training could also supervise this procedure. A certified nuclear medicine technologist should perform technologist FDF PET/CT scans. A medical physicist is needed to optimize an FDG PET/CT study and to ensure these established standards are met. In addition, a medical physicist can help ensure compliance with good practice, monitoring radiation dose, and reducing the CT's radiation burden. Thus a close collaboration and interprofessional team approach is required between referring physicians, nuclear medicine specialists, technologists, and medical physicists to minimize potential hazards to achieve optimal patient outcomes related to fludeoxyglucose.[33] [Level 5]