In 2018, an estimated 1,735,350 cancer diagnoses were made in the United States. Over 600,000 people died from the disease1. That puts the onus on accuracy and expediency in the tools used to diagnose and monitor a patient.
It is also the reason the Positron Emission Tomography/Computed Tomography (PET/CT) scanner has had a significant impact on oncology. Find out what this technology is, how it works, and the benefits of PET/CT when it comes to cancer diagnosis and treatment.
What Is PET/CT?
PET/CT uses small amounts of radioactive materials (radiotracers), a special camera device, and a computer to evaluate a patient's organ and tissue functions. Because it identifies body changes on a cellular level, PET/CT may be able to detect an early onset of disease before it appears on other imaging tests.
This type of nuclear medicine imaging2 also scans the entire body, allowing radiologists and referring physicians to determine the extent of the disease, otherwise known as staging. This allows doctors to determine a more effective course of treatment and monitor that treatment as it progresses.
How PET/CT Identifies Cancer
A PET/CT scan starts with the patient being injected with glucose containing a trace of radioactive materials (radiotracers). Known in the medical field as 18F-fluorodeoxyglucose (FDG), the technologist waits as the organs or tissue in question absorb the substance.
Once complete, a large tunnel-shaped scanner with an optimized camera detector is able to “see” the damaged or cancerous cells. Because cancerous cells typically absorb glucose much faster than healthy cells, this hybrid technology helps medical professionals determine a tumor’s grade based on the cells’ absorption rate as well as the size and location3.
Tumors Types Commonly Evaluated with PET/CT
While it varies based on the situation, the Stanford Health Care identified six tumors where PET/CT has proven to be critical4:
- Lung cancer
- Colorectal cancer
- Head and neck cancer
- Breast cancer
What Makes PET/CT Beneficial for Cancer Treatment
While the technology has been tested for decades, it was Dr. Ron Nutt and Dr. David Townsend who created the first hybrid PET/CT scanner in 2001.5 Seventeen years later, over 2 million PET and PET/CT scans were performed, approximately 7% more than in 20176.
This relatively new technology gives medical professionals a painless way to diagnose and monitor cancerous lesions and tumors in patients. They could potentially eliminate the need for multiple imaging sessions, shortening the exam time and providing several other benefits that are explored below.
Because of the way PET/CT scans illuminate unhealthy tissue, the machine is able to accurately locate cancerous cells fast. Referring physicians use this technology to make early diagnoses and identify relapses in patients7.
Eliminates Invasive Procedures
PET/CT scans could potentially also eliminate invasive procedures such as benign nodule removal and biopsies to determine malignancy. Scientific studies estimate that PET/CT scans correctly identify lesions approximately 93% of the time.8
The accuracy in staging can also prevent patients from undergoing procedures that are not beneficial, helping them avoid unnecessary tissue or organ removal.
Shows Treatment Effectiveness
Oncologists are able to assess the response to and the effectiveness of treatment with PET/CT. The machine quickly identifies any new growth in cancerous cells in comparison with a patient’s previous scans.
This helps guides further therapy by either confirming the response or signaling the need to change course, potentially eliminating ineffective treatments or unnecessary hospitalization.9
Post Surgery Assessment
Oncology patients who are post-surgery may have altered anatomy that make reading CT or MRI scans difficult or impossible.
A PET/CT scan can evaluate the success of the surgery, helping the physician make decisions about the next steps in treatment.8
- “Cancer Statistics.” National Cancer Institute. Available online: https://www.cancer.gov/about-cancer/understanding/statistics. Accessed February 27, 2019.
- “Positron Emission Tomography - Computed Tomography”. RadiologyInfo.org. Available online: https://www.radiologyinfo.org/en/info.cfm?PG=pet. Accessed February 25, 2019.
- “Computed tomography (CT) scan.” Cancer Treatment Centers of America. Available online: https://www.cancercenter.com/diagnosing-cancer/diagnostic-imaging/ct-scans. Accessed February 25, 2019.
- “The Role of PET/CT Scans in Oncology.” Stanford Health Care. (Accessed February 25, 2016). Available online: https://stanfordhealthcare.org/medical-tests/p/pet-ct-scan/what-to-expect/pet-ct-scan-for-cancer.html
- “Radiation in Biology and Medicine: Positron Emission Tomography.” LibreTexts. March 17, 2019. Available online: https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Nuclear_Chemistry/Applications_of_Nuclear_Chemistry/Radiation_in_Biology_and_Medicine%3A_Positron_Emission_Tomography. Accessed February 25, 2019
- PET Imaging Market Summary Report 2019. IMV. February 2019. Available online: https://imvinfo.com/product/pet-imaging-market-summary-report-2019/. Accessed February 25, 2019.
- “PET CT - Neolife Bucharest.” Neolife. Available online: https://www.neolife.ro/en/pet-ct
- Sebastian, S. et al. “PET-CT vs CT alone in ovarian cancer recurrence.” https://www.ncbi.nlm.nih.gov/pubmed/17404789. Accessed February 24, 2019.
- “What Are the Benefits of PET/CT?” org. Available online: https://www.swedish.org/services/cancer-institute/our-services/pet-ct-imaging/what-are-the-benefits-of-pet-ct. February 25, 2019.