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How often PET and CT?

How often it is recommended to do PET or CT? I have been reading the book “ chris beat cancer” and see how much radiation you get when doing them and how radiation exposure is the cause of the secondary cancer.

My dad did PET a month ago and doctor asked to do it again in two months. Is there a recommended frequency or just when it is required? Thanks

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How often will depend on the size and type of cancer. Most followup is with CTs because of the expense of a PET. Most Insurance companies won’t authorize it.

For me, having stage 4 adenocarcinoma, I had CTs every 3 months for 3 years, then every 6 months for 2 years then annually.


Thanks for writing. I have stage 4 adenocarcinoma. Have had chemo, then directed IGFR, still came back and I'm about to start radiation. Was first told 2 months to live--6 months IF I did 4 months of chemo. Then they stopped it at 2 months and started Tagrisso daily saying you'll get 12-18 months on this before your body adapts and it comes back. And the first PET looked great--breast tumor cold, bone tumor cold, glands all cold, just one far smaller lung mass and it only a 3.2--near cold. I heard--once--two years--then this last PET suddenly came back hot in the primary mass and now I'm just hearing get radiation now.

So I'm starting to wonder--just how much time DO I have left.

Is it worth going thru radiation AND chemo at the same time.

And putting my hubby thru it with me?

On medicare only due to being disabled with addisons and only 64 (have to be 65 to get medicare supplement) means 20% of these bills are ours--more on the $17,000 per month tagrisso leftfovers. How can I leave my husband penniless?

But the hospital just wrote that they will write off some of this--which helps.

The fact that you're still here gives me hope.

So thanks TONS for being here.

Will make high dose IMRT radiation I start Monday seem more worth it now.


Sending hope that this kicks the tumor into NED. It’s so very hard to make these choices and I wish you and your husband well. Please let us know how you do.


Let me add that after 8 years of regular CTs, 4 years with breast cancer in a spot that was tagged by my mammography radiologist as a spot to be watched more than 15 years ago, I have not developed a secondary cancer.

After 8 years of advocacy I have only met one person who has developed a secondary cancer. Hers is in a spot that had been radiated for her childhood cancer. Note that is not the lower dose CT radiation it was in a spot that had the focused traditional cancer X-ray radiation that was used over 30 years ago. The secondary cancer took 27 years to develop. (How old will your dad be in 27 years?)

There are many voices out there that will tell you that they have the cure for cancer. BEWARE! There is no single diet or treatment that will prevent or cure cancer. There are people here who have eaten organic, vegan all their lives avoided refined sugars and flour, alcohol and tobacco and still developed lung cancer.

Watch out for quacks:

Someone who claims their treatment will cure every cancer;

Someone who won’t publish their results and attacks his critics;

Someone who claims there is a world wide conspiracy preventing their wisdom from being shared;

Something that is natural-think hemlock, arsenic, coyotes, sharks.

Testimonials- the plural of testimony is not data;

Helps the body heal itself-your body is already doing that and the cancer is using those antioxidants to preserve itself;

They want you to buy their book but have no peer reviews articles;

Western vs Eastern medicine-it’s all medicine and it either been proven that it works or proven that it doesn’t.

If the book or website you are looking at meets any of the above qualifying tests beware. Chris beat cancer meets several of those tests. If you have questions about other groups or programs look them up at quackwatch.org.


Thank you!


Denzil is it possible since last year and a half when they removed my lung tumor right double lobe Tony with 2 involved lymphnones 6 mo chemo 6 week radiation and all negative ct scans wit 4 mo ok then tumor bottom of the brain surgically removed 5 days focused radiation the feb 1 st mri 2 month follow up

They found .5 mm tiny abnormality they just radiated 5 days 3 days later I’m seining off steroids dexmadron for slight arena in the brain, I have a slight headache all day suppose to taper off decadeon till Monday last day... is a slight head ache normal... I’m freakin out I need mri my tumor is back... 1/2 cm very tiny but it spreading to the brain scared me now a second abnormalty


A slight headache is not unusual when tapering off of decadron. It’s a wonderful drug with horrible side effects but without we’d experience horrible nausea.

Is the new anomaly in the same place as the first one? How was it found? Sometimes necrotic (dead) cancer cells appear and they look like a new lesion.

I’ve no personal experience with brain mets but my mom had them as did a number of my friends.


Thank You!! Denzie!! for your advocacy. Your information empowers us with facts and realistic hope. I was dx with stage 4 NSC lung cancer with EGFR + 19del in Dec.2018. Been on Tagrisso for over 2 months. I never smoked and have been living a very healthy life style. I will continue living healthy life style in addition to my medical treatment. Basha❤


Basha, welcome to these boards! And, so sorry for the need that drove you here. Depending on who you talk to, 40-45% of new lung cancer diagnoses never smoked or quit decades ago. How was your cancer found?

If you’re on Facebook there’s a wonderful, private group, called EGFR Resistors. They educate and help new patients with side effects management, social aspects of cancer and advocate. They are actually driving new research in EGFR treatments.

I send hope that your current line of treatment manages to suppress your cancer for a very long time.


👍 I recently joined the EGFR resisters group. It was there that I learned of Healthunlocked. Today after 7 weeks,I had my very first episode which may be my first side effect of Tagrisso. It seems combined with my onset of menopause it was a bit intense but subsided as soon as I gobbled down my 32 OZ water bottle. To be honest, I was terrified like a little kid at first but it seems will have to get used to it and find a better way to manage. Great I will be scouring this site and EGFR site to learn a few tips on helpful remedies for dry skin and rash. 💜 Basha


Have been getting CT scans every three months for over five years. Scans have been clear for two of those years. Have stage 4 nsc adenocarcinoma.


My head aches... not much sleep


His physician likely is following your Dad closely. This is good. He/she must see something that needs watching or they would never have ordered a a PET scan. I get a PET scan whenever a nodule appears to be metastasizing to a quantifiable size to treat. I am under surveillance for growths which requires a CT every 6 months. My last PET scan was is Dec. 2018. I had a small nodule in upper left lung that had been growing at approximately 2-3 mm every 6 months. After the PET scan I received SBRT. Believe me when I say his physician is following many guidelines and established protocols which they must abide by. I have not read the book "Chris Beats Cancer". I myself am not worried about radiation considering the alternative, which is the progressive growth of my disease. Physicians must go through prior approval from the almighty insurance companies before any procedure is done. So they are not giving PET scans willy nilly. God Bless and keep you and your father!

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I had stage 2 squamous cell lung cancer almost 6 years ago. The cancer was removed surgically. After that, I had a CT scan every 3 months, then every 6, then finally in January 2017 I was down to yearly. Unfortunately, my first yearly scan found a "new original" squamous cell lung cancer. I am cancer free again, and back on the every 3 month CT scan schedule.

I have only had 2 PET scans, 1 for each new cancer, but I do have ct scans on a regular schedule.

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Hi Ina,

I’ve had PET scans every 3-4 months since July 2016. We use PET scans because I have a reaction to the CT contrast dye.

I have incorporated COMPLEMENTARY treatments such as acupuncture and massage as well as following a plant based diet, approved supplements, meditation and exercise. I incorporated these into my lifestyle because they have helped with my chemo side effects, stress level and overall sense of well-being. But only after consulting with my oncologist.

Denzie is right, unfortunately there are many ALTERNATIVE cancer treatment hoaxes out there. The best advice I can give you is don’t allow fear to guide your decisions. I believe that most doctors have their patients best interest at heart. That said, a good patient is an informed patient. Learn all you can so you can be a knowledgeable advocate for your Dad.

Wishing you the best.


#PegD, thank you very much for your support. I am trying my best to learn all that I can and provide to my dad and mom back in my country. Sometimes I feel so overwhelmed with so many information out there. I am learning about supplements and diet too. Can you let me know what supplements did doctors recommend? Sometime i worry if I recommend any supplement and what if it interacts negatively with chemo and immunotherapy. Aprico seeds for example, there are many positive things about that but information not always consistent, shall i buy and send it to him? Will it do any harm? These are the worries that I have. Unfortunately doctors there dont give much information on supplements and diet, basically for now i am my dad’s nutritionist. 😄

After yesterdays chemo for example, his feet and face got swallen. Now, I need to start research on that and worry on that too.

Have no idea how much i apprecaite all this information that I get from this forum. Thanks everyone.


You are right to be concerned about supplements possibly interfering with his treatment which is why he should consult with his doctor before taking anything. Getting an appointment with a licensed nutritionist or integrative oncologist would be a good way for your dad to incorporate diet and supplements. I’m not a believer in apricot seeds and in the beginning phases of chemo, I wouldn’t worry overmuch about his diet. The fear of eating/doing/taking the ‘right’ things, in my opinion, adds needless stress and is counterproductive.

As far as the side effects your dad is experiencing, I would say he should report all of these to his medical team. They need to know.

It must be very painful for you being so far away from your parents during this challenging time. While I know you want to help in any way you can, trying to manage his treatment from afar is extraordinarily difficult.

I also know how confusing too much information can be but be very selective when researching on the internet. Many of these websites present their approaches as curative and maybe their approach might have worked for THEM. Unfortunately, without reputable studies it’s a guessing game based on antidotal evidence. Cancer is complicated and each person’s cancer is unique unto itself.

Try not to worry overmuch and continue to reach out. Your parents are blessed with a caring daughter.



Our insurance will only pay for a Petscan every 6 months... My husband is stage 4 lung cancer with mets in bone, spot on adrenal, and some nodes in his chest. He had his upper right lung removed last April, had 2 rounds of chemo..... then nothing for 3 1/2 months. He's been on Keytruda since October which the first CT scan with contrast showed reduction of tumors..... and he's been through radiation on his hip, both femurs and lower back - just went to orthopedic oncologist on Friday and he was very encouraged by his xrays but wants to wait for the next ct scan in a couple weeks.... My husband still has some lower back pain so may still be some undesirables there..... but for the first time in 8 months, he's walking with a cane only and has stamina to live life somewhat normally..... on top of it all, he's a miraculous survivor from 10 weeks in the hospital last summer with septic shock - caused by small intestine perforation from the chemo finding 2 tumors on his small intestine that we didn't know about..... We betting on the Keytruda continuing to do its job.... Best of luck to you.....


Ina, the best advice I got was from my liver oncologist who said to read and rely only on anything that is less than 6 months old and from reputable sources. There are so many quacks out there that are only out to make a dollar and do not care if their proposed treatment actually works. Writing a book about using alternative therapies is nice, but the question to ask is "Are the proposed therapies able to be repeated with others or is this a one-time thing?"

I don't worry about the amount of radiation I get from CTs every 3 months considering the alternative is to let the cancer grow to an unmanageable stage. I've been getting scans since 2002, and have never had secondary cancer due to the scans. My oncologists are clear that when they ask for a list of current medications, they also want to know about any alternatives or herbal supplements because these can change things.

Praying all works out for you


Stage IV NSCLC diagnosed 3/37/25

Currently: Stable

Tx:. CyberKnife, Chemo, Radiation and Immunotherapy.

Last Opdivo was in August 2016.

Stopped due to recurrent low grade pneumonitis. BThankfully by then I was stable.

CT scans now every 6 Months

Brain MRI annually (started with s brain met treated by CyberKnife 2015). Originally had MRI after 3 months, then 6 to 12. I have Labs every 3 months, and Port Flushes every six months. Anytime I have had any symptoms or changes that concern me, my oncologist will order scans, as needed.

I've only had ONE Pet Scan (at diagnosis for staging). All my follow up scans are CT with contrast.

During treatment, I had them every 3 months with Head, Abdomen and Pelvic every 6.

I would much rather have the scans versus waiting too long and finding I had progression. The benefits far outweigh the risks for me.

PS:. I do believe a healthy diet is always a plus for overall health, but I don't believe ANY diet is curative for cancer.

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