Guest guest Posted June 26, 2001 Report Share Posted June 26, 2001 -- In your post dated 25 Jun 2001 you stated that you will receive a 10 mCi tracer dose on 8 Aug. Didn't I read here that the tracer dose should not be over 5 mCi??? Wondering in Ohio () ----- Original Message ----- I have my 10mlc dose set up for Aug 8th, scan Aug 10th. I talked to the nuclear meds guy today & he said I didn't have to follow a LID. As long as I stayed away from Kelp & Sushi I should be fine? I think I'll do the LID just to make sure my scan is accurate! Nov.3/00;lymph node removal, Nov.13/00;pap/thyca, TT..Dec.19/00; 2mlc.RAI, Dec.22/00;100mlc.RAI quarantine ... June 15/01;tg 0.5 ... NOW GETTING READY FOR TRACER BODY SCAN Aug 10th/01! __________________________________________________ Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 26, 2001 Report Share Posted June 26, 2001 Geez!! Isn't medicine Black & White!!!! Why does there seem to be soooo much Gray Area with every aspect of the treatment of this disease!!!!! I thought it was weird too!!! My tracer at Christmas was only 2 or 3mlc? Unfortunately I have to switch hospitals and can't go to the same place I went for the first one because my Insurance has changed (grumble, grumble!) So now I have to swallow a pill instead of the liquid I did last time & last time the scan lasted only 20 minutes or so now this guy says I'll be lying there for 50 minutes. This wouldn't seem so bad if I didn't have " Claustrophobic Panic Attacks " , REAL BAD, when I am hypo!!! Does anybody else know the maximum tracer dosage?????? thanks ... Nov.3/00;lymph node removal, Nov.13/00;pap/thyca,TT .. Dec.19/00; 2mlc.RAI, Dec.22/00;100mlc.RAI quarantine ... June 15/01;tg 0.5 ... NOW GETTING READY FOR TRACER BODY SCAN Aug 10th/01! " donali... " wrote: > -- > In your post dated 25 Jun 2001 you stated that you will receive > a 10 mCi tracer dose on 8 Aug. Didn't I read here that the > tracer dose should not be over 5 mCi??? > Wondering in Ohio > () > > ----- Original Message ----- > > I have my 10mlc dose set up for Aug 8th, scan Aug 10th. I talked > to the nuclear meds guy today & he said I didn't have to follow > a LID. As long as I stayed away from Kelp & Sushi I should be > fine? I think I'll do the LID just to make sure my scan is > accurate! > > Nov.3/00;lymph node removal, Nov.13/00;pap/thyca, TT..Dec.19/00; > > 2mlc.RAI, Dec.22/00;100mlc.RAI quarantine ... June > 15/01;tg 0.5 ... > NOW GETTING READY FOR TRACER BODY SCAN Aug 10th/01! > > __________________________________________________ > Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 26, 2001 Report Share Posted June 26, 2001 You are right, 2-5mCi's is the more typical dose for scanning. 10mCi's is generally considered an amount that would 'stun' the cells so they would not take up additional RAI if an ablative dose is to be given soon afterwards. There is a lot of literature available about this 'stunning effect'. I have scanned with 10mCi's several times (I had lung metastases and they showed up better with the higher dose), but it had already been determined that I would not be receiving an ablative dose after my diagnostic scan. For those times, I went back on meds and had an ablative dose months after that 10mCi diagnostic dose. So sometimes a larger dose is used, but the patient doesn't usually receive an ablative dose afterwards. Marilyn " donali... " wrote: > -- > In your post dated 25 Jun 2001 you stated that you will receive > a 10 mCi tracer dose on 8 Aug. Didn't I read here that the > tracer dose should not be over 5 mCi??? > Wondering in Ohio > () Quote Link to comment Share on other sites More sharing options...
Guest guest Posted June 26, 2001 Report Share Posted June 26, 2001 , You can see which iodine isotope the hosp is using. See repost *********************************************************************** (Dr. ) Date: Fri, 09 Jun 2000 07:39:24 -0400 Subject: Re: Iodine 123 -trial help Sender: thyca-approval@... To: thyca@... Reply-to: thyca@... Message-id: MIME-version: 1.0 X-Mailer: Mozilla 4.7 [en] (WinNT; I) Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT Precedence: bulk X-Accept-Language: en,pdf References: <v04210100b565531195ec@[61.12.22.121]> <v04210101b565e2aa5d8e@[61.12.9.90]> Kaaren, The abililty to detect thyroid cancer depends in part on " image contrast " . Image contrast is based on the amount of uptake in the " target " tissue (thyroid cancer) relative to the amoung of radioactivity in the " background " (surrounding non-thyroid tissue). You can have better image contrast by increasing the amount of uptake in the thyroid cancer or decreasing the amount of radioactivitiy in the background tissue. Most people excrete about 60% of a dose of radioiodine (I-131 or I-123) over 24 hours and about 85% of a dose over 48 hours and 95% of a dose over 72 hours. So about 40%, 15% and 5% are remain in the body at 24, 48 and 72 hours, respectively. That remaining amount contributes to background radioactivity. So the best way to improve image contrast is to wait a longer period of time for excretion of iodine unbound to thyroid cancer. The problem with waiting longer is primarily radioactive decay. With I-131 this is not much of a problem. I-131 has a half-life of 8 days so at the end of 3 days, just 23% of the administered radioactivity is lost due to physical decay. With I-123 this is a much bigger problem. At the end of 24 hours, 73% of the radioactivity is lost due to physical decay, at the end of 48 hours 94% of the radioactivity is lost to decay and at 72 hours over 98% of the radioactivity is lost to decay. So 72 hour imaging is not an option for I-123, unless we start giving people 30 mCi of I-123 for imaging. Again with I-131 we know that 72 hour images have better contrast than 24 hour images and therefore can detect more thyroid cancer. I would expect the same to be true with I-123 if one gave enough of a dose to overcome physical decay. This has to be balanced against the fact that modern gamma camera images I-123 better than I-131. To a modern gamma camera 1 mCi of I-123 in the body looks like 10 mCi of I-131. Will the improved images with I-123 outweigh the problem of having to take images at 24 hours? This is a question that research must answer. Stunning is injury to the thyroid from a scanning dose that prevents a subsequent treatment dose from working. I monitor all of my patients for stunning. It is an extremely rare problem when scanning dose are kept at 2.5 mCi or less. Stunning only occurs because of the therapeutic effects of I-131. I-123 has no therapeutic radiation (beta radiation), so stunning should not occur with I-123. " mttws () " wrote: > Geez!! Isn't medicine Black & White!!!! Why does there seem to be soooo > much Gray Area with every aspect of the treatment of this disease!!!!! > I thought it was weird too!!! My tracer at Christmas was only 2 or 3mlc? > Unfortunately I have to switch hospitals and can't go to the same place > I went for the first one because my Insurance has changed (grumble, > grumble!) So now I have to swallow a pill instead of the liquid I did > last time & last time the scan lasted only 20 minutes or so now this guy > says I'll be lying there for 50 minutes. This wouldn't seem so bad if I > didn't have " Claustrophobic Panic Attacks " , REAL BAD, when I am hypo!!! > > Does anybody else know the maximum tracer dosage?????? > > thanks ... > > > Nov.3/00;lymph node removal, Nov.13/00;pap/thyca,TT .. Dec.19/00; > 2mlc.RAI, Dec.22/00;100mlc.RAI quarantine ... June 15/01;tg 0.5 ... NOW > GETTING READY FOR TRACER BODY SCAN Aug 10th/01! > > " donali... " wrote: > > > -- > > In your post dated 25 Jun 2001 you stated that you will receive > > a 10 mCi tracer dose on 8 Aug. Didn't I read here that the > > tracer dose should not be over 5 mCi??? > > Wondering in Ohio > > () > > > > ----- Original Message ----- > > > > I have my 10mlc dose set up for Aug 8th, scan Aug 10th. I talked > > to the nuclear meds guy today & he said I didn't have to follow > > a LID. As long as I stayed away from Kelp & Sushi I should be > > fine? I think I'll do the LID just to make sure my scan is > > accurate! > > > > Nov.3/00;lymph node removal, Nov.13/00;pap/thyca, TT..Dec.19/00; > > > > 2mlc.RAI, Dec.22/00;100mlc.RAI quarantine ... June > > 15/01;tg 0.5 ... > > NOW GETTING READY FOR TRACER BODY SCAN Aug 10th/01! > > > > __________________________________________________ > > Quote Link to comment Share on other sites More sharing options...
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