RE: Re: Nuclear Bone Scan

[Guest guest]

Thanks – very helpful. Anyone interested in the subject might like to

have a look at this report which I collected on another Forum http://www.hindawi.com/journals/au/2012/893193/

All the best

Prostate men need enlightening, not

frightening

Terry

Herbert - diagnosed in 1996 and

still going strong

Read A Strange Place for unbiased information at http://www.yananow.org/StrangePlace/index.html

From: ProstateCancerSupport [mailto:ProstateCancerSupport ] On Behalf Of C

Sent: Wednesday, 7 December 2011

3:47 AM

To: ProstateCancerSupport

Subject:

Re: Nuclear Bone Scan

Terry --

From here:

http://www.world-nuclear.org/info/inf55.html

" The radioisotope most widely used in medicine is technetium-99m, employed

in some 80% of all nuclear medicine procedures - hence some 30 million per

year, of which 6-7 million are in Europe, 15 million in North America, 6-8

million in Asia/Pacific (particularly Japan), and 0.5 million in other regions.

It is an isotope of the artificially-produced element technetium and it has

almost ideal characteristics for a nuclear medicine scan. These are:

>>>

It has a half-life of six hours which is long enough to examine metabolic

processes yet short enough to minimise the radiation dose to the patient.

<<<

Technetium-99m decays by a process called " isomeric " ; which emits

gamma rays and low energy electrons. Since there is no high-energy beta

emission the radiation dose to the patient is low.

The low energy gamma rays it emits easily escape the human body and are

accurately detected by a gamma camera. Once again the radiation dose to the

patient is minimised.

The chemistry of technetium is so versatile it can form tracers by being

incorporated into a range of biologically-active substances to ensure that it

concentrates in the tissue or organ of interest.

Its logistics also favour its use. Technetium generators, a lead pot enclosing

a glass tube containing the radioisotope, are supplied to hospitals from the

nuclear reactor where the isotopes are made. They contain molybdenum-99, with a

half-life of 66 hours, which progressively decays to technetium-99. The Tc-99

is washed out of the lead pot by saline solution when it is required. After two

weeks or less the generator is returned for recharging. "

FWIW, I think that a four-hour wait, and a six-hour half-life, means that there

was enough radiation coming off the technetium to give a good scan result.

That's a wild-ass guess. I don't know if the radiologists use " correction

factors " for the time between the removal of the Tc from its generator,

and the time of the scan.

>

> I've just had my fourth bone scan, which was clear this time - the last

one

> had an area 'suspicious for metastasis' which was enough for the

oncologist

> to accept it as definitive.

>

>

>

> But..knowing how inaccurate all scans are, and how busy they were at the

> hospital yesterday, a thought struck me and I thought I'd ask for some

> input.

>

>

>

> I have in the past had the injection of the nuclear material two hours

> before the scan. My understanding of the procedure was such that this was

> the optimum time for the take up of the material before the material

started

> to decay as it has a short half life. Yesterday it was four hours before

the

> scan started and four and a half hours by the time it finished.

>

>

>

> I don't know what material was used, but if for example it was

> 99mTc-methylene diphosphonate (99mTc-MDP) which seems to be commonly used,

> is it likely that the scan's accuracy might be affected by the additional

> two hours before the scan was done?

>

>

>

>

>

> All the best

>

> Prostate men need enlightening, not frightening

>

> Terry Herbert - diagnosed in

1996 and still going strong

>

> Read A Strange Place

for unbiased information at

> http://www.yananow.org/StrangePlace/index.html

> <http://www.yananow.net/StrangePlace/index.html>

>