Positron Emission Tomography, or PET imaging provides several benefits in oncology. PET permits a physician to accurately image many organs of the body with a single scan to detect malignancy. PET has demonstrated usefulness in cost-effective, whole-body metastatic surveys, allowing patients to avoid biopsies.
The benefits of PET include non-invasive differentiation of tumors from radiation necrosis; the possibility to change the course of ineffective chemotherapy; and avoidance of unnecessary diagnostic and therapeutic procedures.
Applications for PET imaging in oncology include:
Brain Tumor
- Differentiate a recurrent tumor from radiation necrosis
 - Differentiate primary CNS lymphoma from toxoplasmosis
 - Exclude brain metastatic disease
 
Breast Cancer
- Identify involved axillary nodes or distant metastatic disease
 - Exclude local recurrence of disease
 - Evaluate response to treatment
 
Colorectal Cancer
- Detect locally recurrent or distant metastatic disease in patients with elevated or rising CEA who may be candidates for surgical re-excision
 - Rule out distant metastases for preoperative evolution
 
Head & Neck Cancer
- Determine extent of local, regional, and distant disease
 - Detect recurrent/residual tumor following definitive therapy
 
Lung Cancer
- Distinguish malignant pulmonary nodules from benign ones
 - Stage mediastinal or distant metastatic disease
 - Use as part of radiotherapy treatment planning
 - Detect recurrent/residual tumor following definitive therapy
 
Lymphoma
- Determine extent of disease and measure treatment response
 
Melanoma
- Identify extent of local and regional disease spread in patients with high risk melanoma (e.g., primary tumor less than 4mm) or in suspected recurrence
 
Musculoskeletal Tumors
- Evaluate local extent of disease and exclude distant metastases
 - Measure treatment response and exclude recurrent/residual tumor following definitive therapy
 
Ovarian Cancer
- Detect recurrent/residual tumor prior to surgical exploration or additional chemotherapy
 
Pancreatic Cancer
- Differentiation of benign processes such as pancreatitis, mucinous cyst adenoma, and pseudocyst from malignant disease
 - Rule out distant metastases during preoperative evaluation
 
Thyroid Cancer
- Detect metastatic or locally recurrent disease in patient with elevated thyroglobulin after definitive initial treatment and negative I-131 examination
 
Sources & Studies
- Conti, P.S., Lilien, D.L., Howley, K., Keppler, J., Grafton, S.T., Bading, J., PET and F-18 FDG in Oncology: A Clinical Update. Nuclear Medicine and Biology,(1996) 23:717-735.
 - Di Chiro, G., Positron Emission Tomography Using FDG in Brain Tumors: A Powerful Diagnostic and Prognostic Tool. Investigational Radiology, (1986) 2:360-371.
 
