OVERVIEW
PET-CT is an important diagnostic and predictive tool in cancer treatment. From diagnosis to staging, from monitoring to evaluating a patient’s treatment response, PET-CT plays a pivotal role in all major phases of the cancer journey.
PET-CT (Positron Emission Tomography-Computed Tomography) is a nuclear medicine imaging method that combines the structural information from the CT scan with the metabolic activity information from the PET scan for more reliable and detailed diagnostic information.
The data from PET and CT imaging are combined for two- or three-dimensional image reconstruction with the help of a software system. These combined scans help oncologists pinpoint anomalies and devise the best treatment plan for various cancers and other diseases.
How Does PET-CT Work?
Before the scan, the radiotracer is injected into the patient’s vein. A radiotracer consists of a radioactive isotope and a biomolecule, such as glucose. Later, the patient is asked to wait for about 45–60 minutes for the radiotracer to be absorbed by the body cells.
Once the radiotracer is injected, it reaches those regions in the body that utilize glucose.
Tumor cells, for instance, absorb more glucose as they need the energy to divide rapidly. During the imaging, we will be tracking the radioactive emissions from the radioactive isotope that is tagged with glucose. Those areas with increased glucose or radiotracer absorption appear as bright spots. That said, even brain cells and kidney cells absorb more glucose; therefore, for a definitive diagnosis, it is important to combine a PET scan with a CT scan.
A special camera is used to detect these radioactive emissions and produce images of the metabolic activity of the scanned region. A CT scan that is carried out simultaneously captures the X-ray images of internal organs from different angles.
A computer then combines the data from PET and CT scans to produce 3-dimensional images of internal organs. Any abnormalities, like tumors, can be easily and accurately detected through a PET-CT scan.
Advantages of PET-CT Scan
PET-CT imaging has numerous advantages:
Through enhanced accuracy, PET-CT supports the right diagnosis and, thereby, the right clinical decisions.
PET-CT helps specialists detect cancers in their early stages, when they can be treated with positive outcomes.
By providing highly reliable information about the lesions or abnormal masses, PET-CT imaging helps in effective treatment planning.
PET-CT imaging also helps assess the patient’s response to the treatment given.
In some cases, PET-CT can help prevent unnecessary invasive procedures and retests by providing helpful, comprehensive molecular and structural data at once.
This imaging process is non-invasive, and in most cases, there will be no downtime or recovery required for the patients after the test.
PET-CT imaging also plays an important role in radiotherapy planning.
