A PET, or positron emission tomography, scan is a nuclear medicine imaging test. PET uses radioactive matter to show how organs and tissues are working and pinpoint disease. Combined with CT (computed tomography), PET/CT scans provide detailed 3D images of bone, tissue and organs for accurate cancer diagnosis.
PET can often distinguish between benign and malignant lesions when CT and MRI cannot.
PET/CT is the most useful test for determining the stage of cancer. It is more accurate than any other test in finding local or metastatic tumors. PET/CT is used to:
- Show whether a tumor is cancerous or not
- Stage lymph node tumors accurately
- Detect metastatic tumors, resulting in more accurate treatment
- Evaluate response to therapy, allowing changes if necessary
- Show whether cancer has returned
- Biopsy localization, especially for small lesions or for large, partially necrotic masses.
- Plan radiotherapy treatment