U.S. doctors online nowAsk doctors free
Ben Lomond, CA
A 59-year-old female asked:

In a patient who has a very fast growing/high metabolic activity cancer, how small a tumor can be detected on a high-res pet scan?

3 doctor answers20 doctors weighed in
Dr. Barry Rosen
General Surgery 35 years experience
1-2 centimeters: The sensitivity of pet scanning (in combination with ct) is dependent on the origin and metabolic activity of the cancer and the part of the body that is being scanned. In general, most 2 cm cancers will be identified; as many as 1/3 of all cancers less than 1cm may be missed.
Created for people with ongoing healthcare needs but benefits everyone.
Dr. Michael Thompson
Hematology and Oncology 21 years experience
8-9 mm: A radiologist might provide a more detailed answer, but i generally think of a cutoff of 8-9 mm, but that might also depend on cancer type, proliferator rate, and technical issues.
Created for people with ongoing healthcare needs but benefits everyone.
Dr. Joseph Accurso
Radiology 30 years experience
Depends: If the tumor is very FDG avid (takes up lots of the tracer), and is surrounded by tissue that takes up little/none, then it can be detected down to 5 mm or so. A more typical size is more like 8-10 mm, but remember, even that that is only 1/3 of an inch! an anatomic study, such as a ct, would rarely if ever call something that small suspicious except for lung nodules.
Created for people with ongoing healthcare needs but benefits everyone.
Last updated Jan 13, 2016

Disclaimer:

Content on HealthTap (including answers) should not be used for medical advice, diagnosis, or treatment, and interactions on HealthTap do not create a doctor-patient relationship. Never disregard or delay professional medical advice in person because of anything on HealthTap. Call your doctor or 911 if you think you may have a medical emergency.