Nuclear medicine
Nuclear medicine is the medical specialty that diagnoses, evaluates and treats various types of diseases. These include cancer, infectious diseases, heart disease, as well as gastrointestinal, endocrine, neurological and other disorders.
The examinations or diagnostic tests carried out in nuclear medicine identify specific metabolic/molecular changes for each type of tissue or organ, making it possible to detect diseases in their earliest stages and to assess the degree of response to various therapies, mainly oncological.
It is a minimally invasive speciality and does not require complex technical procedures. The imaging tests are similar to other more familiar tests such as CAT or MRI, and in many cases involve less radioactive exposure.
PET-CT
The imaging study with the greatest impact is PET-CT. It is a test that combines two different technologies in one machine: Positron Emission Tomography (PET) + Computed Tomography (CT).
PET itself is a non-invasive diagnostic technique that makes it possible to visualise metabolic activity in the body using a “contrast agent” made up of glucose and a positron-emitting radioisotope (F18). The procedure is based on the fact that in certain pathologies, mainly oncological, there is a significant consumption of glucose due to high cell replication, so that the administration of this “contrast agent” allows us to detect the presence of tumour activity at a very early stage, both in the initial phases of the disease and in the case of possible recurrences. This has marked a turning point in medical oncology, making it possible to treat patients in the earliest stages of the disease and to determine the true extent of the disease, which will have a significant impact on survival.
Over time, and thanks to major technological advances, it has become possible to combine the metabolic or functional PET image with the anatomical/structural image obtained by CT (computed tomography) in the same machine and using the same procedure, avoiding unnecessary overexposure to radiation and significantly improving the precision (sensitivity and specificity) of the study.
PERFORMING THE TEST
The patient can be reassured that the test is done on an outpatient basis, without the need for hospitalisation. The only preparation is to eat a low carbohydrate meal at dinner the night before and then fast for at least four hours before the scheduled time of the test. There may be some exceptions, especially for diabetics, so this is important information to give to the nuclear medicine staff when requesting a PET-CT scan.
Finally, when the patient arrives at the nuclear medicine department, he/she will be taken to a private room called the injection room, where a nuclear medicine nurse will insert a peripheral line through which the ‘contrast agent’ will be injected. After the injection, the patient will have to rest for about 50 minutes, a time that many patients use to read, listen to music or just relax. After this time, which is necessary to allow the “contrast agent” to concentrate in the possible areas of disease, the patient is taken to the PET-CT room where the imaging study is performed, a procedure that takes about 20 minutes. Once the procedure is complete, the patient can go home and lead a normal life.
