Use of PET/CT in Oncology

Positron Emission Tomography/ Computed Tomography(PET/CT) is a non-invasive diagnostic imaging procedure that can provide unique information for accurate TNM staging. Many cancers exhibit increased glucose metabolic rates which can be identified with PET/CT via the radio-pharmaceutical 18F-FDG. Since changes in glucose metabolism often occur before changes in anatomy (e.g. tumor growth), PET/CT can often identify the presence of disease earlier than other anatomic imaging techniques. Early disease identification is particularly critical during the assessment of nodal involvement or the determination of the presence of metastatic disease.

The clinical value of PET/CT in Oncology includes: early detection of disease, precise staging of disease, and determination of response to treatment. Because FDG highlights the uniqueness of cancerous tissues, much of the clinical application for PET/CT is focused in oncology.

In general, the diagnostic accuracy of PET/CT is superior to that of other complementary diagnostic exams. In addition, PET/CT often demonstrates a higher sensitivity and specificity as compared to CT alone.


 Diagnostic Accuracy1
 Cancer Type Conventional Imaging PET/CT
Breast 67% 89%
Colorectal 80% 94%
Gastro-Esophageal 68% 83%
Head and Neck 65% 87%
Liver 81% 93%
Lung 68% 82%
Lymphoma 64% 88%
Melanoma 80% 91%
Pancreatic 65% 81%
Testicular 68% 92%
Uterine/Cervical 43% 87%
1Source: The Journal of Nuclear Medicine Supplement, Volume 42, Number 5, May 2001 and UCLA