Ct/bone scans evry 3 mos in trials....any need to worry?

[Boywonder56]

Heading says it all....i guess if i start glowing ill know🤢

[FCoffey]

The link below shows a graphic prepared by Randall Munroe for his comic XKCD.

xkcd.com/radiation/

I modified it to show the typical dose from a PET/CT scan.

postimg.cc/xJZQsSs2/9113c3dc

The dose is about half of the maximum dose allowed for US nuclear workers in one year. In a PET/CT scan, most of the dose is delivered in less than an hour.

Rate matters. When doctors bluster to me about how we all get background radiation (shown in the blue box in the graphic), I point out that first, the PET/CT scan is a far larger dose, and then I propose a little test.

Let's put out two piles of strychnine, 100 mg each. The doc can eat theirs all at once. I'll divide mine into 365 doses and take some every day. After a year we can sit down for a nice cup of tea and discuss dose rate response.

As Munroe notes:

"If you are basing radiation safety procedures on an internet PNG image and things go wrong, you have no one to blame but yourself."

Some things that might be wrong with the altered graphic:

- Not all PET/CT scans give the same dose of radiation. Modern scans may use less - or more.

- The graphic is for one scan, not many.

Speaking strictly for myself, I insist on whole body MRI scans.

jcdr.net/article_fulltext.a...

The authors note that

"But as the oncology patients are already weakened, not only by the disease entity itself, but also by chemotherapy, there is a possibility that the exorbitant diagnostic radiation which is involved in the bone scans or the PET-CT scans may turn out to be the proverbial last straw on the camel’s back. It is noteworthy that MRI can detect bone metastases even before they manifest on the bone scan."

The first rule of medical radiation safety is not to accept a dose that isn't necessary. MRI has zero ionizing radiation. If my whole body MRI scan shows a suspicious lesion, I might accept a PET/CT scan, but only if the doctors convinced me it would change their recommendations for treatment.

There are risks to PET/CT scans, and there are risks associated with refusing those scans. How any person weighs those risks is a personal choice, there is no right or wrong answer.

[cesanon in reply to FCoffey]

I discussed this with Dr Almeida.

He said because of the economics getting a pet/MRI they are pretty much unattainable. There are few such machines. And those that exist don't have teams experienced with doing prostate cancer scans. And even if willing it would be very expensive, and no insurance company would cover it.

He also implied that using a pet/MRI is good (for soft tissue I think) but not so good for other things.

My takeaway from the discussion is that if you want a scan, you are stuck with pet/CT.

If anyone knows where to get a Pet/MRI with either Auximin contrast or psma contrast, please say so.

Thanks

[FCoffey in reply to cesanon]

My answer was about whole body MRI as an alternative to PET/CT, not PET/MRI. The link I provided has a fairly complete discussion and details.

Any modern MRI machine can be set up to perform this type of scan. It is faster and much less expensive than PET/CT. My last scan was $675 including the radiologist's report.

It is not a prostate scan. Neither is PET/CT. Both scans image the whole body and are primarily used to identify distant metastases. In prostate cancer that's very likely to be in bone, and whole body MRI is particularly good at detecting bone metastases. As the linked article mentions, by sensing changes in bone structure rather than attempting to directly image very small tumors, whole body MRI will often find lesions that are missed on PET or CT scans.

[cesanon in reply to FCoffey]

Fcoffey

That is very interesting. $675 for a no radiation MRI scan sounds pretty interesting to me.

Does it use any contrast agents?

Do you know where I can get one, by someone who has experience doing it for prostate cancer?

Where did you get yours done?

[Tall_Allen]

I'd worry if I had to have more than 10 and my life expectancy were over 20 years

[Boywonder56 in reply to Tall_Allen]

Ive had 10 bone / 10 ct..in 2 yrs...but my os was 2yrs....beating this c like a redheaded step child...qol...still 8 out of 10.....want to take the "lupron vacation".....they say no way......your a champ t/a....give a lot of people hope....

Bw..

[Mormon1 in reply to Boywonder56]

Please be more succinct. Thanks.

[cesanon in reply to Tall_Allen]

Allen,

What do you think about using Inositol and inositol hexaphosphate (IP6), to moderate the adverse effects of radiation therapy?

It seems it might help. Then again maybe they could impair the intended effect of the radiation.

What do you think?

[Tall_Allen in reply to cesanon]

It is definitely something to avoid with therapeutic radiation. Bone scans/CT are a source of full body low level radiation and the long term effects of getting a lot of that are not well known. You want healthy cells to commit suicide (apoptosis) when they get ionizing radiation they cannot recover from. Apoptosis requires that reactive oxygen species (ROS) be generated. Antioxidants may interfere with ROS formation. When damaged cells can't undergo apoptosis because a person has overloaded on antioxidants, those cells may activate oncogenes (i.e., become cancerous). The safest bet is to exercise - that increases cell oxygenation, supplying ROS as needed, and supporting the health of healthy cells.

[cesanon in reply to Tall_Allen]

Tall Allen,

Fcoffey mentions full body scan MRIs.

Do you have any blog articles on that?

For $675 it seems like a no brainier to me.

[Tall_Allen in reply to cesanon]

Actually, most clinicians frown on it, and it's not just the unnecessary expense. It will find lots of cysts and other benign growths (we all have them) that will cause one to investigate further, perhaps intrusively. Also MRIs are not good at finding prostate cancer, which is what we have bone scans and PET scans for. PET/MRIs are available at a handful of institutions in the US and are better at finding mets, but the limit is still around 4 mm. (You can get lower than that with a USPIO MRI- available only in the Netherlands). Ask yourself - what is it that you are looking for and what will you do about it if you find it?

[cesanon in reply to Tall_Allen]

Tall Allen

1. So even a psma pet only finds 4mm or larger?

2. What is USPIO MRI and how small can it go?

[Tall_Allen in reply to cesanon]

1. Well a PSMA PET/ CT finds lesions 4 mm or larger (You need the CT or MRI to localize it)

2. USPIO (ultrasmall super-paramagnetic iron oxide) is an MRI contrast agent (aka Combidex) that accumulates in healthy lymph nodes but not cancerous ones. Jelle Berentz at Radboud University claims it can detect lesions as small as 2 mm.

[cesanon in reply to Tall_Allen]

Oh yes, Combidex. I had the US version of that at Sand Lake a long time ago.

It works for bone as I remember. How well does it do for soft tissue?

[Tall_Allen in reply to cesanon]

No, it only works for lymph nodes, not bone. The kind they used at Sand Lake Imaging wasn't Combidex - it was Fereheme (similar, but it did not work well so they abandoned it).

[cesanon in reply to Tall_Allen]

"it was Fereheme (similar, but it did not work well so they abandoned it)."

Was it false positives or false negatives?

[Tall_Allen in reply to cesanon]

They never reported it (they should have).

[MelaniePaul]

No, I wouldn't worry about that. As stated here many times before, I think have very regular and frequent scans is good and important.

[Mormon1 in reply to MelaniePaul]

I hope so.

[rust]

I've had 3 sets of bone and CT scans in the last 13 months plus 1 Axumin PET scan. The EMBARK clinical trial I am in has CT/bone scans every 6 months. No I am not enthusiastic and fear the 6 month scan frequency is very bad for me at age 51.

[Hidden]

I am on my second drug trial for a total of 6 years. Had bone/CAT scans every other month. No I'll affects yet.

[Mormon1 in reply to Hidden]

Wonderful. Blessings