PET Scan

 

I had a PET (Positron Emission Tomography) Scan on Tuesday to try to determine whether my cancer has spread. Here’s a Wikipedia article: http://en.wikipedia.org/wiki/Positron_emission_tomography    I won’t know the results until my 9/26 meeting with my Oncologist.

Apparently a PET scan is different from other scans in that it detects changes at the cellular level.  http://my.clevelandclinic.org/imaging-institute/imaging-services/pet-scan-hic-pet-scan.aspx

And it is based on sugar.

I’d wondered at the prep instructions: a zero-carbohydrate diet the day before the scan.  And no caffeine within 12 hours before the scan. No exercise the day of the scan.  Here’s how it was explained to me.

Cancer cells are very fast growing; thus they need a lot of nourishment. At the cellular level, sugar is nourishment.   They want you to go in with relatively low blood sugar.  They also want your body to be as calm as possible, therefore no stimulants such as caffeine; and no exercise that would get your muscles active and looking for nutrients.

You get an IV injection of a sugar solution that contains a radioactive tracer. Then you rest for about an hour. Again, no stimulation: no reading, no writing – you just relax in a recliner in a dimly lit room. It takes about that long for the solution to circulate throughout your system.  

After that you are positioned on the scanning bed and the scan begins. Depending on the area being scanned, it can take from 30 to 60 minutes.  My scan was from base of the skull to my femur heads – took about 40 minutes, I guess.

I was relieved to find that the scanner itself is a relatively short tube with a large diameter so claustrophobia was not an issue.  You just lay there and let the bed carry you through the tube while it takes pictures of your insides.  Any fast growing cells needing nutrients will glom onto the sugar and its radioactive tracer and will show up in the pictures.

I’m not glad that I needed the scan but it was an interesting process.  I hope I get to see the pictures.