PET Scan vs CT Scans

[kimblanchard]

Hi everyone,

Can you tell me when your docs used PET scans vs. CT scans? My mom is in the process of being staged for SCLC and we are just beginning this long road. Mom is not a candidate for MRIs since she has a pacemaker.

Should she have a PET to determine extent of the cancer or is that used later in the process??

Mom has a 2cm X 3 cm tumor in her upper right lobe and one enlarged lymph node 3cm X 4cm near her heart.

Thanks, in advance, for all your "expert" input.

[berisa]

hi soccermon

I would suggest to have PET scan for staging as it may spread to other parts of body that PET scan is to scan the whole body trunk (but not really the best choice to scan brain, brain MRI is the best choice for brain). CT scan is good to measure the size.

So, I would suggest to do PET scan for staging although someone said PET scan is not 100% accurate and it is only around 90% accurate. My dad did the pet scan for staging as well. Actually, when PEt scan shows something abnormal, they will suggest to do some more clinical correlation to better making conclusion.

Hope this helps.

[kimblanchard]

Hi Soccermom,

Once they were sure it was SCLC by bronchoscopic tissue biopsy they did my initial staging with CT scans and a bone scan. After chemotherapy the tumor disappeared from CT scans and then a PET scan was ordered. My radiation oncologist seems to think that the tumor remnants are still there in my chest, but small, and he arraigned for the scan at a center 20 miles from my hospital. PET uses dextrose labeled with a positron emitting fluorine atom to locate areas of tissue with high metabolic activity. The sugar goes to the hot spot and the positron annihilations emit two identical gamma rays in opposite directions. By catching the two rays in scintillating crystals, their point of origin can be calculated and a three dimensional, or tomographic image can be plotted. This metabolic hot spot image is electronically fused with an X-ray CT scan, which shows all tissues. High sugar uptake is not proof of cancer, but is good evidence of a probable neoplasm. In my case it is being used to re-stage my SCLC to determine if more local radiation therapy is indicated. I had the test done last Tuesday and have not yet been informed of the result. It was an uncomfortable procedure where you must sit very still for an hour, while the injected radioactive sugar equilibrates, and then lay on your back for a second hour with this giant machine circling you. My arthritis bothered my back and my arms were pinned at my side with a cloth sling across my chest. My nose itched and my breathing was difficult, but if I ever do it again, I’ll take some pain medication before I start.

Good luck.