PET Scan/CT Scan - are they different?

mum-of-four
mum-of-four Member Posts: 22
edited March 2014 in Colorectal Cancer #1
Firstly, thank you for all the lovely replies to my "coming to the end of my chemo thread" it made me feel so much better (and normal!!) Well I finally got the last one out of the way last week and feel physically better today. Had my CT scan yesterday - results 13th October.

My elder sister suggested I also had a PET scan, which I would have to pay for privately (I'm in UK) which I could do, but I don't know if it will give me any extra information to the CT scan.

I'm diagnosed as Dukes "C" (is that the same as stage III?) when my bowel was removed, 2 lymph nodes were affected.

She seems to be under the impression that the PET scan will be able to give info about the lymph nodes, but I'm not sure this is the case.

Any feedback would be most appreciated

thank you

Kerry

Comments

  • betina61
    betina61 Member Posts: 642 Member
    #2
    Hi Kerry, thank you for your response about my platelets low count, it allways help to see that other people have been there, and I am so glad that you finished your tratment, as you said I'll be there too, about the difference between pet scan and ct scan I don't know, I was going to post the same question,so I am glad you did I
    will be watching the answers, because I am sure that next month probably the Dr. will send me for one of the two. I had a pet scan before surgery and I allways wondering which is best. Hopefully we will get some good answers.
  • Patrusha
    Patrusha Member Posts: 487
    #3
    Hi Kerry,

    Yes, Dukes C is equivalent to Stage III. And there is a difference between CT and Pet scans. CT scans basically look for things that shouldn't be there... it's a "cold" scan looking for bumps and lumps. A Pet scan looks for "hot spots" of rapid cell growth and can pick up new tumors that the CT scan does not. When my chemo is done I'll be asking for a PET scan. Hope this helps.

    Why will it take until Oct. 13 to get CT results? Is that the usual in the UK? I got mine in a day or so, so I'm just curious. That wait would kill me!!!
  • chynabear
    chynabear Member Posts: 481 Member
    #4
    Dear Kerry,

    Yes, a PET and a CT are "different". They are often used together to gain a bigger picture and offer a higher % of being accurate.

    In the US it is becoming the standard follow-up for Stage III (I believe this is your staging as there were lymph nodes involved). There is now a machine that does both the CT and PET at the same time and the computer itself stacks the images rather than doctors doing this.

    The CT is great for finding masses or tumors while the PET is great for finding cancer.

    Cancer loves and feeds on sugar. When you have a PET, they inject you with a radioactive glucose (sugar) and then take "slice" images of your body. Cancerous areas with "light up" on because they will draw and consume the sugar (radioactive glucose).

    PET scans are often used if something shows on the CT scan, as well.

    In the US, different insurance companies are sometimes picky about picking up the tab for PET scans. I had to fight with my insurance for a year to cover two that I had.

    What I don't understand is (a) the PET and CT and PET/CT looked to be about the same $$ charged to the insurance company and (b) it provides a more detailed picture.

    Anyway, being stage III, I would recommend getting at least one PET scan and go from there. I know they can be expensive, so maybe you can choose to have one a year down the road if it makes you feel better.

    Keep in mind, very small cancer cells will not likely show on either scan. It must first be a certain size, 1 cm comes to mind, before it shows up on any scan.

    Sorry I missed your "coming to the end of my chemo" thread. Congrats on reaching that milestone.

    I remember finding these boards after I finished chemo and feeling better and "normal".

    Just out of curiousity, how come you have to wait until October 13th to find out the results of the CT scan?

    Here, I can often have my scan in the morning and know the results by that evening, the next day at the latest.

    Here's to a clean scan and NED!!!

    Patricia
  • mum-of-four
    mum-of-four Member Posts: 22
    #5
    chynabear said:

    Dear Kerry,

    Yes, a PET and a CT are "different". They are often used together to gain a bigger picture and offer a higher % of being accurate.

    In the US it is becoming the standard follow-up for Stage III (I believe this is your staging as there were lymph nodes involved). There is now a machine that does both the CT and PET at the same time and the computer itself stacks the images rather than doctors doing this.

    The CT is great for finding masses or tumors while the PET is great for finding cancer.

    Cancer loves and feeds on sugar. When you have a PET, they inject you with a radioactive glucose (sugar) and then take "slice" images of your body. Cancerous areas with "light up" on because they will draw and consume the sugar (radioactive glucose).

    PET scans are often used if something shows on the CT scan, as well.

    In the US, different insurance companies are sometimes picky about picking up the tab for PET scans. I had to fight with my insurance for a year to cover two that I had.

    What I don't understand is (a) the PET and CT and PET/CT looked to be about the same $$ charged to the insurance company and (b) it provides a more detailed picture.

    Anyway, being stage III, I would recommend getting at least one PET scan and go from there. I know they can be expensive, so maybe you can choose to have one a year down the road if it makes you feel better.

    Keep in mind, very small cancer cells will not likely show on either scan. It must first be a certain size, 1 cm comes to mind, before it shows up on any scan.

    Sorry I missed your "coming to the end of my chemo" thread. Congrats on reaching that milestone.

    I remember finding these boards after I finished chemo and feeling better and "normal".

    Just out of curiousity, how come you have to wait until October 13th to find out the results of the CT scan?

    Here, I can often have my scan in the morning and know the results by that evening, the next day at the latest.

    Here's to a clean scan and NED!!!

    Patricia

    Thank you ladies, that's really helpful information

    re: scan results

    I'm in the UK and the majority of us here don't have private medical. We have what's called the NHS (National Health Service) which we pay into when we are working and it provides our health care, free, when we are ill. Even when we're not working (which I'm not at the moment), we are still entitled to get free treatment.

    Anyway, the upshot is if I was private, I would probably have results straight away but with the NHS you always have to wait at least a couple of weeks. (The wheels of government agencies turn slowly!) To be honest though, most UK citizens would agree, that however much we moan about the shortfalls of the NHS, that when the chips are down and you have something really serious, the best place to be treated is in the NHS. So basically, I haven't had to pay a penny for any of my treatment.
  • jana11
    jana11 Member Posts: 705
    #6
    Kerry,

    Hi. I am a stage 4 survivor and a doctor. DO NOT pay for a PET scan unless the CT scans has findings that show you need more information.

    I've gotten all my care at MD Anderson over the past 4.5 years with 3 different cases of new lung mets. I have only had 2 PET scans.

    PET scans are NOT part of standard follow up care. Yes, PET scans inject radioactive sugar into your body and then you lay VERY still for 1 hour so areas of your body that use greater glucose will "light up". Cancer doesn't "feed" on sugar, but it does have a greater metabolism than the rest of the body. As well as any areas of inflammation or infection. PET scans do NOT give any absolute data. They can be helpful if a small nodule/lesion is seen on CT, and the docs aren't sure if it is cancer. If the PET then lights up brightly, the chance it is cancer is greater.

    So, DO NOT PAY the money for it - it is a waste. Wait to get the CT results and talk to the docs about whether or not a PET is needed for more information. Cancer is all about one step at a time - don't get ahead of yourself. :)

    I hope this helps. Good luck and I hope you never need a PET. :)

    jana
  • vinny3
    vinny3 Member Posts: 928 Member
    #7
    Hi Kerry,
    Glad that your chemo is completed. The CT scan will show spots but usually there are enough characteristics to actually show that it is cancer. The PET scan goes over the same areas after you have ingested radioactive sugar. Since the cancer cells metabolize faster than normal cells there will usually be more of the sugar taken into the areas of cancer and thus "light up" on the PET scan. These are then compared to the CT scan (mine were done at the same time and on the same machine). One doesn't need the PET scan unless there are abnormal spots on the CT scan. Unfortunately for testing but fortunate for us, many of us have spots which show up (I had some in liver and lungs) on the CT scan but are normal cysts or other "things" we tend to have. The alternative to getting a PET scan after a CT scan which shows spots is to get a followup CT in 3 months to check to see if the spots have changed (thus indicating possible tumor growth) but I would rather push for a PET scan at that point.

    ****

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