Cancer Community
Accuracy of PET scan
About This Community:

This patient support community is for discussions relating to cancer, cancer staging, chemotherapy, hormonal therapy, radiation therapy, surgery, and tumor types.

Font Size:
A
A
A
Background:
Blank
Blank
Blank
Blank Blank

Accuracy of PET scan

My dad had a pet scan to check for a return of cancer.  It came back with no hot spots.  But what is strange is that a CAT scan showed a mass on his pleura of his lung.  They thought it may be a recurrent thymoma which he had removed 4 years ago.  He did have a bx of the area.  No results available yet.  If it were a recurrence of the thymoma wouldn't the pet scan have showed a hot spot?  What could this mass be.  They said it was about the size of a nickle.
Related Discussions
Avatar_dr_m_tn
Hi.  Positron Emission Tomography or PET scan involves the use of a radioactive form of glucose (fluorodeoxyglucose or FDG), which is introduced into the body and taken up by the body's organs in differing quantities, depending on that organ's metabolic rate.  The assumption is that cancer cells will have a higher metabolic rate than normal cells, would take up FDG more avidly and show up on the scan as a "hot spot".  While this assumption is true most of the time, it's possible for the growth rate (and consequently, the metabolic rate) of a cancerous mass to slow down after it has attained a certain size.  Hence the mass doesn't show up too well on PET since the FDG uptake has also slowed down.  Another possibility is that the mass, although malignant, is largely necrotic.  Lots of dead cells means less FDG uptake.  The third possibility is that the mass seen on CAT scan is non-cancerous and does not have an increased metabolic rate.  

Anyway, the biopsy was the right thing to do, since it's going to provide you with a more definitive answer than PET or CAT scan.
Blank
Post a Comment
To
Blank
Weight Tracker
Weight Tracker
Start Tracking Now
Cancer Community Resources
RSS Expert Activity
233488_tn?1310696703
Blank
New Cannabis Article from NORTH Mag...
Jul 20 by John C Hagan III, MD, FACS, FAAOBlank
242532_tn?1269553979
Blank
3 Reasons Why You are Still Binge E...
Jul 14 by Roger Gould, M.D.Blank
242532_tn?1269553979
Blank
Emotional Eating: What Your Closet ...
Jul 09 by Roger Gould, M.D.Blank
Top Cancer Answerers
612551_tn?1247839157
Blank
Jerry_NJ
NJ