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PET Scan instructions

JDuke's picture
JDuke
Posts: 443
Joined: Nov 2009

I was just visiting over at the Colorectal forum. There was a post regarding pre-PET instructions. Several members mentioned that they were told to follow a low-carb diet prior to their PET. One member also said that they tested her blood sugar level each time, pre-PET scan. I have never been given these instructions, nor had my blood tested, and I have had five PET scans. Curious about the rest of you here, what was your experience?
Seems there is a lot of inconsistency within the medical community.
Blessings to all for a wonderful day!

z's picture
z
Posts: 1272
Joined: May 2009

Joanne,

The last pet I had I was instructed not to eat for 6 hours prior to the scan. When I arrived they tested my blood sugar to make sure it was in normal range. The medicine they give you to drink prior to the scan is some type of glucose concoction. Since cancer tumors intake all the sugar they can, thats what makes the pet show the activity of any cancer tumors as they suck up the glucose and as they say light up the cancer tumors. Lori

cbs6931's picture
cbs6931
Posts: 63
Joined: Mar 2010

Could not eat or drink after midnight for am scan. They did test my blood to make sure the blood sugar was in a normal range. It was, and they injected me with dye and proceeded with the scan. No special instructions on diet. It is funny about the differences, guess there is some reason, just not sure what.

Cathy

mp327's picture
mp327
Posts: 3115
Joined: Jan 2010

I'm so glad this topic has come up. There seems to be some variations in what people are being told in preparation for the PET scans. I am always advised of the following:

1) Nothing to eat or drink 4-6 hours prior to the scan.
2) No strenuous exercise 24 hours prior to the scan (as explained by my radiologist friend, this is because exercise can cause inflammation, which can show up as a hot spot on the scan)

As for the blood test, they have always tested me prior to scanning. I asked the tech what number would prevent someone from having the scan and he said they will do them up to a blood sugar reading of 200.

Also, there has been some controversy over doing CT scans with or without contrast for anal cancer. Everytime I've had a CT scan, I've always had to drink a bottle of contrast a few hours prior, then another half bottle right before the scan at the hospital.

I agree with Joanne, inconsistency seems to exist. What is right, what is wrong, who knows.

duckyann
Posts: 162
Joined: Jun 2009

My instructions were Nothing to eat after midnight if it was an am scan, light breakfast if it was an afternoon scan. No strenuous exercise 24 hours before. No alcohol 48 hrs. before. I had blood tests done when I got there but I did not know that it was for sugar level. I had to drink 1 glass of contrast when I first got there sit for 45 minutes and drink another one and 15 mins after they would take me in to do the scan. I also had the radio active dye shot through me after a few pictures without it.

susan1069
Posts: 30
Joined: Mar 2010

Just wanted to add a comment about the PET scan. I had my period when I went and ended up with a false positive in my cervix and uterus which led to an ADDITIONAL surgery to biopsy the area. There was absolutely no cancer in there and my ob/gyn is sure that somehow the period showed as inflammation on the PET scan. There is documentation on MEDline of this happening to other people , so just keep this in mind when going. Anyway, this surgery pushed back my treatment start date for an additional 3 weeks while I healed, which was a real drag because I was all ready to go!

mp327's picture
mp327
Posts: 3115
Joined: Jan 2010

That's very interesting and something I've never heard of. Good for all our gals here to know. Thank you for sharing.

gypsy509
Posts: 11
Joined: Jun 2010

FYI
I had one just last week and my instructions were a low carb diet the day before including no fruits, soda. No food or drinks except water six hours prior and no alcohol 24 hrs prior.

Sundanceh's picture
Sundanceh
Posts: 4342
Joined: Jun 2009

No hard physical exertion 24-hours prior to the test.

No sugars 24-hours prior to the test.

And I would fast between 8-12 hours prior to the test to make sure that my glucose counts were as low as possible - never wanted to give them any margin for error in reading the tests. They were so expensive and when they are over, you get to eat, so didn't want to gum it up all up for hunger - after what I went through, it was a minor inconveience.

My counts were usually between 99-120, which were well within range for a good test.

My whole journey consisted of not getting the correct information or any information at all - but fortunately for the many members here, the information can be pooled and shared among everyone, thus lightening their loads and easing their worried.

Ya'll have a great day, right JoAnne?

-Craig

sissy310
Posts: 300
Joined: May 2010

going for my first PET scan this week and was only told to not eat 6 hours prior. I did not realize that they give you something to drink prior to the PET. Glad I looked in here. Am finding out so much which is preparing for all these tests. Thanks.

sissy310
Posts: 300
Joined: May 2010

going for my first PET scan this week and was only told to not eat 6 hours prior. I did not realize that they give you something to drink prior to the PET. Glad I looked in here. Am finding out so much which is preparing for all these tests. Thanks.

mp327's picture
mp327
Posts: 3115
Joined: Jan 2010

Sissy--

I would highly recommend avoiding any type of strenuous exercise for at least 24 hours prior to the exam and avoiding caffeine for that length of time also. Exercise can cause inflammation and inflammation can light up on a PET, giving a false positive. I've never been told to avoid sugar or eat low carb prior to a scan, but it couldn't hurt, so you may want to do just that. I wish you the very best with your scan--may your results be good!

sissy310
Posts: 300
Joined: May 2010

Thank you. I will follow your advice...I did have to laugh about the strenuous exercise...it's something I NEED to do and have not. I think it is important to eat right, exercise and just stay less stressed -- dang is that ever hard to do.

pjjenkins's picture
pjjenkins
Posts: 173
Joined: Mar 2009

Hey, guys,
I think there is no drink before a PET- they infuse something. There is a drink before a CAT with contrast. I have had 3 PETs and 2 CATs and that is the way I remember it. Also, for folks with a possibility of being around pregnant women, I was warned to be extra cautious after the PET and not go around my pregnant daughter for 24 hours. The PET infusion is mildly radioactive. The CAT dye is not.

Will be thinking of you through this week, Sissy. I hope your doc will meet with you very quickly after taking the test!

Priscilla

mp327's picture
mp327
Posts: 3115
Joined: Jan 2010

I always have to drink either a half of a large bottle or a small bottle of contrast at the hospital before my PET scans. They have me do this while they are testing my blood sugar and getting me ready for the IV. Once they walk me to the trailer where the mobile PET scanner is, they infuse the FDG (radioactive glucose) through the IV. Then I sit for almost an hour while the stuff goes through my body. They take me to pee, then put me on the machine and do the scan. My routine has always been the same and I've had 7 PETs.

cbs6931's picture
cbs6931
Posts: 63
Joined: Mar 2010

I've had one PET/CT - Did not have anything to drink and did not have an IV (just a large shot ). Did have a blood sugar test. Did have a waiting period while the material dispursed in my blood stream. Wonder if the differences are based on the type or brand of equipment used to do the scan? I have another scan scheduled soon and will try to remember to ask.

sissy310
Posts: 300
Joined: May 2010

I did not expect this to be the way it worked so I am glad you explained it. I think part of the fear and anxiety is not knowing what is going to be done. I'm one who, if I know that this and this and that will be done prior and during, I handle things better. I know what is coming.

On another note, have any of you tried different cancer free type diets or cut out sugar or did any meditation along with all of your treatment? I'm curious as to whether that is more to help the person's mental state and keep calmer (feeling there is something they are doing) or if it actually helps. I'm new to all this so I apologize for any naive comments or questions I ask. Thank you so much.

grateful1
Posts: 81
Joined: Jun 2010

I LOVE SUGAR--BUT I BOUGHT SUZANNE SOMERS BOOK KNOCKOUT AND GAVE UP SUGAR AND DIET SODA IMMEDIATELY

sissy310
Posts: 300
Joined: May 2010

Thanks for your thoughts. I did not know that about the PET and my friend's daughter is 3 months pregnant - had a tough time getting there so I will be sure to stay far from her for awhile. I will be meeting with the radiologist/oncologist on the 15th so I will only have a few days after the tests to worry and wonder. I'm very anxious to hear what they find, what I'm facing and where to go from there.

grateful1
Posts: 81
Joined: Jun 2010

I JUST HAD MY SECOND AND I WAS NEVER GIVEN THSE INSTRUCTIONS-JUST TO FAST THE NIGHT BEFORE- BY THE WAY DO YOU KNOW HOW TO POST HERE. I HAVE TO START THE LOW IODINE DIET FOR RADIATION THANKS GOOD LUCK

pjjenkins's picture
pjjenkins
Posts: 173
Joined: Mar 2009

To start a new topic, and yours sounds interesting, after you come to Discussion Boards and select Anal Cancer, at the top of the list of topics you can click on "Start a New Topic". It is pretty self-explanatory there though I kinda remember something that irritated me for a minute. (I get pretty irritable with technology!)
PJ

Chris3
Posts: 53
Joined: Mar 2010

I just had my second PET Scan. Mine had a 48 hour prep - augh! My scan was at 1pm on Wednesday. On Monday midday, I was to stop with any solid food. Monday early evening, I had to drink 4 liters of Gavilyte to "clean" out my system. Then all day Tuesday I could only have clear, sugar-free liquids (broth, sugar-free jello or soda, water). Then at 9am on Wednesday, I could only have water. Upon arriving at 1pm then they took the water away. I was injected with radioactive dye and told to sit quietly for 1 1/2 hours. The instructions also said no exercise, walking, heavy housework (<-- the only benefit!) on Monday, Tuesday or Wednesday. By the time I was done with my scans (also had a chest CT) it was after 4pm. I thought I was going to faint! I lost 5 pounds.

(Had a funny(?) nightmare on Tuesday night before my scan. I dreamt I was asking my doctor how often I would need follow-up scans. The nightmare doctor said I would need a PET Scan weekly for the first 3 months. I woke up in a cold sweat!)

mp327's picture
mp327
Posts: 3115
Joined: Jan 2010

Wow Chris. You are the first person I've heard about having to do this sort of prep prior to a PET scan. It sounds almost similar to prepping for a colonoscopy! I am having a PET on 7/28 and my instructions are no vigorous exercise for 24 hours, no caffeine for 12 hours, and nothing to eat for 4 hours prior to the scan--water is ok. I have inquired when I had previous PET scans (I've had 7 previously) about cutting back on carbs prior to the scan. The tech told me that even things I had eaten the evening before would not affect the scan. At my hospital, they will do scans on anyone with a glucose level below 200. I also only have to sit for about an hour after the glucose injection. Do they have you drink any contrast prior to the scan? I always have to drink a small bottle. You poor dear, I bet you were about ready to faint after all of that! Weekly PET scans--now that's a scary nightmare! I hope your results come back all good!

Chris3
Posts: 53
Joined: Mar 2010

I've had 3 colonoscopys and the PET Prep is worse! I was really jealous when I read the other posts talking about the shorter prep time. Oh well... like you said, not a lot of consistancy.

When I had my PET, I didn't need contrast - just the radioactive IV. When I had my 2 Pelvic CT Scans, then I was injected with contrast.

z's picture
z
Posts: 1272
Joined: May 2009

I just was told no eating 6 hours before. That was about it. I had a pet-ct merged images. Dreams are so funny, and I am glad that this was a dream, I certainly wouldn't want a pet every week. LOL. Lori

pjjenkins's picture
pjjenkins
Posts: 173
Joined: Mar 2009

Hi, Chris,
My sympathy on your prep! Mine was more like MPs as previously written. No wonder you had a nightmare! I suspect there are none among us who would be able to deal with WEEKLY scans!!! LOL!

susan smiles
Posts: 12
Joined: Jul 2010

I have known for a long time that cancer is fed by sugar, the first time they gave me a PET scan, 8 years ago. The Glucose goes straight to the cancer to feed it. So why don't they tell that to cancer patients? Xylitol is a healthy form of sugar that cancer patients can have. It actually increases the white blood cell count. It has to be made from Birch Bark and not Corn as most corn is GMO. Global Sweets is a good source. Tell them, The SilverSpoon Chef recommended it to you. They are really nice!

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