PET scan vs MRI and CT scan?

Didiabolical
Didiabolical Member Posts: 18
in Anal Cancer #1

Hi everyone, hope you're all feeling ok this lovely (but windy here in the UK) Saturday morning...

Just a quick question which I'm hoping someone will be able to throw light on...I'm due to have my first follow up scans on 20th and 21st January  - they're giving me a CT scan and an MRI scan however, when I was first diagnosed, I was sent for a PET scan as supposedly, these show more detail eg whether the cancer has spread to lymph nodes etc. On my first biopsy/ diagnosis, my cancer had spread to my lymph nodes so I don't really understand why they're not giving me a PET scan this time? Could it just be as simple as expense?

Di

Comments

  • TraceyUSA
    TraceyUSA Member Posts: 316
    #2
    Good Question

    I have never got a specific answer to this question other than each has it's advantages and shows something a little different. 

    I just had a MRI (pelvic and abdominal) which takes about 1.5 hrs.  (it's much longer than the 20-30 min. PET/CT's I've had)  My oncologist prefers the MRI's and my radiology oncologist prefers the PET (maybe because he has the machine at his facility.)  They are willing to alternate scans, so I have a MRI at one check-up interval and the PET at the next (I'm almost 2 years post treatment and have graduated to 6 month check-ups). 

    I'm curious to see if anyone else has a more definitive answer.

    -Tracey

     

     

  • mp327
    mp327 Member Posts: 4,440 Member
    #3
    Didiabolical

    I have had both PET scans and CT scans over the nearly 6 1/2 years since my treatment ended as part of my follow-up.  My doctor would prefer PET/CT scans every time, but of course, my insurance will no longer pay for PET scans, so most of mine have been CT's.  I believe a CT scan along with an MRI should be enough for your doctors to determine that you are in good shape.  If you check the latest NCCN guidelines for follow-up of anal cancer, scans of any type are no longer suggested for routine follow-up, except in cases of T3 or T4 or inguinal node postive cases.  They only mention "imaging," including chest, abdomen and pelvis, but do not specify as to what type of scan.  Of course, you would fall into the inguinal node positive group.  I cannot answer your question as to if expense is a factor, but as with most things medical these days, I'm guessing it has something to do with it.

    Good luck on your scans.  Please let us know your results when you have them.

    Martha

  • nicotianna
    nicotianna Member Posts: 209
    #4
    Di

    I googled your topic.  It provided a wealth of detail!  I came to this conclusion:  cost & accessibility seem to be more of an issue in the decision of what is done.  The PET picks up metabolic activity & also grades it (SUV).  In my case, I have only had PET/CT scans.  PET/CT is relatively new.  I am 15 mos. post XRT (radiation).  My 1st PET/CT was at 3 months & then almost every 3 mos.  One was done at ~ 6 weeks when a nodule was found in my lung.  I hope this info is helpful to you.  I had bilateral inguinal node involvement (IIIb).

    Keep us posted!  Wishing you pristine films:)

    Nic 

  • eihtak
    eihtak Member Posts: 1,473 Member
    #5
    Di.......

    This is one of those questions that will have varied responses.  As mentioned only "imaging" is recommended depending on Stage. I had a Pet scan when initially diagnosed and again at 1 yr but all others have been CT.  Just yesterday I had my (almost) 4 yr CT scan. I have had one every six months but every 12 months include chest and pelvis as well as chest x-ray.  My schedule is a bit off because (almost) 3 yrs ago I was diagnosed with breast cancer as well for which I did also have a follow-up MRI.

    My doctor had a family emergency out of town so will not meet with him until next week for results......fortunately I feel great and am not expecting any surprises but still keeping very busy this week to avoid letting that anxiety creep in!

    katheryn

  • mxperry220
    mxperry220 Member Posts: 496 Member
    #6
    Scans

    PET scans can give a false positive particularily right after treatment because the radiation is still very active.  The PET/CT scans expose one even to more radiation each time they run a scan.  With the MRI there is no exposure to radiation with this scan.

    Mike

  • Ouch_Ouch_Ouch
    Ouch_Ouch_Ouch Member Posts: 508 Member
    #7
    Next....

    Hello, Didiabolical:

    mp327's point about insurance coverage holds true for other companies in the USA, too.  Some cap the number of PET scans allowed per patient. This implies that they are either pricier or riskier or both.

    mxperry220 also has good points - that a PET cannot always differentiate between cancer hotspots and the continuing effects of radiation therapy and inflammation. If your insurance company limits the number of PETs you can receive, there's no use wasting one when there can be potential false positives obtained.

    PET scans and CT scans of the chest and abdomen also deliver higher doses of radiation compared to other types of scans. Having both of them would double the amount delivered. When I had a the pre-treatment PET/CT, I was told to stay away from children and pregnant women. In addition, I was given a card to show to the police in case I set off their radar scanner on my way home!

    Information site for the American College of Radiology and for the Radiological Society of North America - http://www.radiologyinfo.org/
    Chart of radiation risks per procedure - http://www.radiologyinfo.org/en/safety/?pg=sfty_xray

  • swood9008
    swood9008 Member Posts: 116 Member
    #8
    Ouch_Ouch_Ouch said:

    Next....

    Hello, Didiabolical:

    mp327's point about insurance coverage holds true for other companies in the USA, too.  Some cap the number of PET scans allowed per patient. This implies that they are either pricier or riskier or both.

    mxperry220 also has good points - that a PET cannot always differentiate between cancer hotspots and the continuing effects of radiation therapy and inflammation. If your insurance company limits the number of PETs you can receive, there's no use wasting one when there can be potential false positives obtained.

    PET scans and CT scans of the chest and abdomen also deliver higher doses of radiation compared to other types of scans. Having both of them would double the amount delivered. When I had a the pre-treatment PET/CT, I was told to stay away from children and pregnant women. In addition, I was given a card to show to the police in case I set off their radar scanner on my way home!

    Information site for the American College of Radiology and for the Radiological Society of North America - http://www.radiologyinfo.org/
    Chart of radiation risks per procedure - http://www.radiologyinfo.org/en/safety/?pg=sfty_xray

    pet scan vs ct/mri

    My mom was diagnosed 2 weeks ago to what seems to be stage ii anal cancer, she has had a cat scan that was clear for lymph node involvememt, and also mri for measuring, she is scheduled for a pet scan wednesday, I guess my question is how accuarte the ct and mri vs pet scan, her doctor said he doesn't forsee any surprises but cant be sure. I won't sleep easy until her pet scan 

  • mxperry220
    mxperry220 Member Posts: 496 Member
    #9
    swood9008 said:

    pet scan vs ct/mri

    My mom was diagnosed 2 weeks ago to what seems to be stage ii anal cancer, she has had a cat scan that was clear for lymph node involvememt, and also mri for measuring, she is scheduled for a pet scan wednesday, I guess my question is how accuarte the ct and mri vs pet scan, her doctor said he doesn't forsee any surprises but cant be sure. I won't sleep easy until her pet scan 

    Scans

    I had PET, CT, and MRI before any treatment plan.  The doctors analyzed all three results before they developed a treatment plan.  I have been cancer free since 2009.

    Mike

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