What is PET/CT?
The PET/CT is an imaging method that combines the techniques of PET (Positron Emission Tomography) and CT (Computed Tomography), and providing more comprehensive information than each can separately provide. The most advanced method in the world used in the diagnosis and monitoring of cancer, PET/CT has many advantages for both doctors and patients.
Digital images obtained with PET-CT are directly transferred to the computer and are used in planning radiation therapy.
What is PET (Positron Emission Tomography)?
Cancer cells supply the energy they need to grow and proliferate from glucose. In PET technology, glucose is labeled with a radioactive substance and injected to the patient. Then, cancerous tissue with radioactive glucose uptake is externally viewed. Although PET is quite reliable to tell whether an abnormal tissue is cancerous or not, question marks may remain about localization of the tumor or whether the site of radio-labeled glucose uptake has a normal tissue or not, because sufficient anatomic information is not provided.
What is CT (Computed Tomography)?
CT imaging, also known as tomography by the public, is a method that enables to visualize anatomic structure of the body in detail. With CT, it is possible to know the location and dimensions of a tumor. However, it is not possible to understand whether the tumor is malignant or benign.
PET and CT combination
PET/CT is based on combining PET which provides images of cell metabolism and CT that provides anatomic details in the same instrument. Therefore, the metabolic function of cells and anatomy can be visualized comprehensively by a single device in a single session. Doctors can have detailed and conclusive information about the anatomic and metabolic condition of the patient with the help of 3-D images. PET/CT enables fast and proper diagnosis of cancer and cardiac diseases in particular.
Thanks to PET-CT which is used to monitor response to therapy during cancer treatment, it is possible to determine structural and functional characteristics of the tumor and to identify the treatment site accurately. In the meantime, it enables to spare the healthy tissue surrounding the tumor as much as possible. Compared with other planning methods, it reduces side effects of radiotherapy significantly, while enabling delivery of radiation to the tumor at high doses.
In addition, PET/CT is valuable in the diagnosis of brain diseases, notably dementia and epilepsy, and facilitates early diagnosis of Alzheimer’s disease.
How does the procedure take place?
Patients who are to enter PET/CT device are first injected an agent which is absorbed by cancer cells likely to be present in the body in 45 to 60 minutes. Then, screening starts and the patient remains in supine position for 35-45 minutes.
What are the benefits of PET-CT?
In addition to providing great advantages compared with other diagnostic tools, PET/CT eliminates the need for diagnostic tests that involve too much radiation. Images obtained with this recent technology have critical importance in the diagnosis of cancer, and constitute an important part of the decision process at the Tumor Council.