Operating with Parma General Hospital

What is PET-CT?

The PET (Positron Emission Tomography) is an innovative non-invasive Nuclear Medicine imaging technique used in many fields: in oncology it enables an early diagnosis and immediate assessment of the effect of a treatment, in neurology it helps assess brain disorders, in cardiology it shows the vitality of heart tissues, in orthopaedics it detects possible infections.
It is not a screening exam but an investigation and it is carried out to answer specific clinical questions. The PET provides very precise and detailed images about the metabolism of organs and tissues by following the behaviour of some molecules, first of all sugar (or glucose).
In oncology, tumour cells use a lot more sugar than healthy tissues; when these cells stop using sugar it means they are dieing and that the treatment is effective.
The PET requires the use of a radioactive agent or tracer which is introduced into the body intravenously. The most common radioactive sugar used is deoxyglucose (a molecule of sugar) marked with Fluorine-18 (18F-FDG). The PET can detect the distribution of 18F-FDG inside the body.
The PET-CT is an imaging tool which combines two scan techniques, a PET scan and a CT scan. It yields both types of images at the same time by merging PET images (metabolism) with CT images (structure and/or shape). This scan provides information on the anatomy of the tissues examined and accurately detects possible pathologies.

What are PET-CT benefits?

• Information provided by a PET-CT scan cannot be obtained using other types of exams;
•The combined PET and CT scans yield images that accurately locate abnormal metabolic activity and help find the right treatment for many types of illnesses
•PET-CT scan provides both functional and anatomical imaging of tissues and thus allows accurate and early diagnoses

PET-CT common clinical applications

PET-CT scans are performed to:
• detect the early onset of tumours by measuring the metabolism of a suspicious lesion identified using other diagnostic procedures;
• determine whether a tumour has spread in the body;
• assess the effectiveness of a treatment plan, such as cancer therapy;
• monitor tumour relapse after therapy;
• assess the benefits that patients with coronary diseases and ventricular dysfunction can have by undergoing surgical treatment;
• determine the effects of a heart attack;
• provide an early diagnosis of Alzheimer disease and differential diagnosis versus other types of neurodegenerative disorders.

Preliminary information

Before a PET-CT scan patients should:
• take no food or drink for at least 6 hours before their procedure;
• avoid a meal rich in carbohydrates on the evening before the scan;
• drink abundant water;
• avoid strenuous activities the day of the exam;
• bring all clinical reports about their pathology;
• bring along at least half a litre of water.

Risks

• pregnancy;
• breast feeding;
• radiotherapy treatments carried out less than three months before the scan;
• surgical operations, diagnostic procedures (biopsies) and/or invasive therapy procedures (radiofrequency) carried out less than a month before the scan.