X ray or PETCT? - 1253172

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X ray or PETCT? - 1253172

I have been told that the radiation produced by PETCT is much greater than by X ray, so my oncologist prefers to use X ray imaging and CEA to monitor my situation. My last PETCT was done on 28th Nov. and the most recent X ray shows a growth from 1.2 to 1.4 cm on my right lung; however my M.D. still recommends X ray for the coming month. With sore muscles around my pelvic from time to time I am concerned whether there are any bone mets, and wondering whether a PETCT should be done to detect bone mets. So my questions are:
1. In general, how often a PETCT should be taken?
2. Should bone and other mets be detected as early as possible to facilitate early treatment, or there won't be any difference whether the mets are found earlier or later?
3. How oncologists balance the side effects of using PETCT versus the possible delayed discovery of new mets?

Many thanks!



55 Never-smoker Asian female, diagnosed IV NSCLC July 2012, Exon 19 deletion, on Iressa since July 2012.

Reply To: X ray or PETCT?

Hi Tracey,
I'm very sorry for your diagnosis. The standard of care with following stage 4 nsclc is by CT alone somewhere between 6 and 12 weeks, closer to 12 weeks when there is an expectation of control following several months of good reviews from tarceva with an egfr mutation. Doctors will move that schedule up is symptoms demand.

The reason CT alone is used over a PET is the PET is more expensive and doesn't show a benefit over CT and sometimes an elevated suv from PET leads to premature discontinuation of a good treatment.

CT's on the other hand are lots of xrays taken sequentially down the body building a high resolution picture of the body, in someone with stage 4 nsclc it would be the chest area. So yes there is more radiation given but it is still a relatively small amount and it is still low enough to be much more useful than dangerous when following someone with lung cancer, curable or not.

CEA tests have not been found to be useful as a stand alone monitor. x rays are thought to not add enough to be worthwhile.

With all that said my husband gets both pet scans and xrays. He wouldn't ask and I don't question it (anymore) because the pet scan every 3 months has given him what he needs If it were costing blue cross too much I'm sure we'd hear about it. But someone is being charged too much somewhere because of it I'm sure.

Usually a bone met becomes more painful with time which is the sign for the oncologist to investigate further. The fact that it comes and goes and isn't to bothersome is a good sign.

I'm not a doctor, but have been here enough to have a bit of knowlege here because they are some of the most common questions.

There is quite a lot written about these subjects and can be found through a search (you may need to log off first depending on your browser) or you can check out our FAQs and INFO


All Best,

Reply To: X ray or PETCT?

I know I've said too much when I run out of room before I finish.

We want you to use our libraries because they are packed with fabulous useful info but don't hesitate to ask questions either.

forum moderator

See I was almost done.

Reply To: X ray or PETCT?

Hi Tracey, I just want to share our experience. My wife's oncologist has the same approach. He prefers to monitor 3 things: (1) X- Ray, (2) Blood Test, (3) Symptoms, as surveillance protocol while my wife is on Iressa. It was upon our request that he obliged ( in his words "just to satisfy our anxiety") to a 6 monthly PET and Brain MRI. The logic of this as I gathered (from various sources, primarily the direct input from the treating doctor and the discussion in this forum) are:
(1) While X-Ray and Tumor markers are individually not that reliable, using the combination of 3 indicators could be good enough to detect any meaningful progression.
(2) In the context of advanced lung cancer, it could likely be no change of treatment plan even when progression is detected early before the manifestation of any symptom. An important takeaway here is a quote by Dr West in one of the threads of this forum: "the only thing that knowing about metastatic recurrence earlier vs. later provides is an opportunity to know (perhaps worry, perhaps prepare — perhaps both) and to start treatment associated with side effects before there are any symptoms to treat.”.

However, we continue to request regular scans as we still want to hold on to, perhaps stubbornly, the belief or hope that early detection allows consideration of early intervention options, albeit limited, that may prevent or delay or lighten some effects of disease progression.

Hope this helps.

Dr West
Reply To: X ray or PETCT?

As has been discussed here, a PET scan is very sensitive, and perhaps too sensitive, since it can detect problems before anyone would notice them as problems (which begs the question of how serious a problem they are if you need detailed tests to learn you've got them). One advantage is that they cast a very wide net, identifying problems pretty much throughout the body. I think it's very reasonable to do more detailed tests, whether a PET scan or MRI, etc., to evaluate a suspicious new symptom like focal pain in a bony area, or a head MRI in someone with a new headache or loss of balance, but it's not a very productive exercise in someone who doesn't have new symptoms to suggest that there is something to look for.

My personal view is that a chest x-ray is about as useful as just looking at a person. You're probably as likely to find someone is progressing by seeing that they look unwell as by finding progression on an x-ray, a technology that is over a century old. While I consider a PET scan an exceptionally sensitive way to detect progression, arguably too sensitive, I see a chest x-ray as an almost disingenuous way to do surveillance for progression. It's so insensitive for anything short of striking progression that it seems like something just done as a ritual to be doing something that seems almost like doing a meaningful test. There's no evidence it helps more than just seeing a person in the clinic and monitoring for symptom changes, and I really think it mostly just humors everyone into feeling like imaging is being done. To be frank, I really think of it as the placebo arm of a study of meaningful follow-up.

I don't mean to say that I never do a chest x-ray, because they can be helpful for certain questions, and they're easy and low radiation, but they really aren't very helpful in determining whether there's mild progression of a cancer being treated.

-Dr. West

Dr. Howard (Jack) West
Medical Oncologist
City of Hope Cancer Center
Duarte, CA

Founder & President
Global Resource for Advancing
Cancer Education

Reply To: X ray or PETCT?

Dear Dr. West and all:

Thank you so much for your advice and sharing. I am basically asymptomatic (at least up to this moment) apart from mild and discontinuous sore muscles on the back and around the left pelvic, which, the doctor said, might have been caused by sitting and working long hours in front of the computer (I am still working full-time), so symptom could not be used to indicate my current condition. After reading your advice and experiences, I think I shall try to arrange a low dose CT, so I can know my current situation better.

As a recently diagnosed lung cancer patient fighting with this deadly disease alone (I am single and with no relatives in HK), I am indeed very grateful to you all, and will definitely look at the library next time when I have more questions.

Best wishes,


55 Never-smoker Asian female, diagnosed IV NSCLC July 2012, Exon 19 deletion, on Iressa since July 2012.