Nuclear Medicine Institute
Information for PET / CT patients
PET / CT is one of the most modern examinations of contemporary medicine. It allows to detect a number of pathological conditions, especially in oncology, cardiology, neurology, pneumology, urology, and is also used in the detection of inflammatory and degenerative processes. It consists of two examinations - positron emission tomography (PET) and computed tomography (CT). While PET determines the rate of cell damage, CT (computed tomography) determines the exact location of the affected lesion. The examination is usually carried out in the range of head to thigh, respectively. whole body. The following are used as PET radiopharmaceuticals (medicinal, possibly diagnostic preparations with bound radioactive substances):
- FDG: radioactive fluorine-labeled sugar (fluorodeoxyglucose), which accumulates in cells with increased metabolism, which are often cancer or inflammatory cells, most commonly used in the diagnosis of lymphomas, lung tumors, melanoma and various infectious or non-infectious inflammatory conditions. The most commonly used substance.
- Fluciclovin (FACBC, Axumin): an artificial amino acid designed to search for tumor lesions in a suspected recurrence of prostate cancer
- Choline: a substance that is involved in the formation of cell membranes and is also used for the localization of prostate tumors, also liver cancer, ev. it can help to find enlarged parathyroid glands.
- F-DOPA: part of hormone production of adrenal medulla, used to search for tumors with increased production (pheochromocytoma, paraganglioma, certain types of thyroid tumors - medullary carcinoma)
- FLT: the substance involved in DNA formation (fluoro-L-thymidine) allows to locate areas of increased cell division, used to determine the radiation treatment effect of radiotherapy.
The amount of radiopharmaceutical administered to the body is very small and administered intravenously.
Subsequent CT is generally performed using iodine contrast, which is administered to a vein or drunk as decided by the physician. CT scans are performed to determine the pathology of the lesion and assess the structural changes of the organs and are also optimized to minimize the radiation exposure. The contrast medium allows the individual tissues in the body to be assessed and to distinguish pathological changes from the healthy parts.
The radiopharmaceutical has practically no side effects, does not cause allergies or other health complications. The contrast agent can cause an allergic reaction, which is mostly of a light nature (sneezing, feeling warm, nausea), and in the case of severe reactions (shortness of breath, swelling and the like), immediate help is available in the ward. Occasionally, life-threatening allergic reactions have occurred in the world.
The daily capacity for two-shift operation is about 15 patients per day (less depending on the type of examination, for less complex types of examinations).
The examination takes approximately three hours, and the procedure and duration may vary for each radiopharmaceutical. Due to the irregular delivery and variability of operation, it is not possible to plan everything precisely and PET / CT testing is associated with longer waiting times. The most commonly used FDG runs in the following stages:
- preparation before application: patient in waiting room, administrative reception, introduction of intravenous needle (cannula), instruction and signature of informed consent
- FDG application: intravenous (total 5 min.)
- waiting for the accumulation of FDG in the body: the patient is in a separate box, stays still (takes 1-2 hours)
- PET / CT scanning: usually with the application of a contrast medium to an already established cannula (the patient is in the instrument's tunnel - it takes about 30 minutes)
- checking images and patient: approx. 30 min before computers process and produce an evaluable image (patient control for allergic reaction or other complications).