[Isotope-prod] Reminder VCU Talk Monday 11:30 CC F224-5

Tue Sep 29 17:27:01 EDT 2015

Hi Pavel:

You are absolutely right that stable Cu photo-production is far too small to matter.   The impurities that one fights are:

1)      Stable Cu from other sources (impurities in the original target, target holder, processing devices, materials, fluids, etc.)

2)      Other (stable) metals with similar chemistry that creep into the 67Cu product, in the same way that stable Cu creeps in.

3)      Any and all additional radioactivity (Cu or otherwise) that creeps into the 67Cu product that induces additional dose for no benefit to the experiment, imaging or patient.

Also, parenthetically, note that the upcoming AccApp’15 conference of the ANS (November 10-13, in DC) has several talks relevant to this project:

http://accapp15.org/attend/program-preview/

In particular, one talk (below) is from a 67Cu photo-production project that I led and was PI when I was at Idaho State U.   I have had very little contact with that group since I left ISU, so it will be interesting to see how far they have gotten.  It would be well worth our time to pay careful attention to their methods & results of  Cu-cleanliness:

Wednesday, November 11, 2015, 1:00 P.M.
Accelerator Production of Radioisotopes—I, Session Organizer: Lia Merminga (TRIUMF)
High Specific Activity e- LINAC Production of 67Cu, Jon L. Stoner, Alan W. Hunt, Frank Harmon, Timothy Gardner (ISU)

Thanks---D

From: Pavel Degtiarenko [mailto:pavel at jlab.org]
Sent: Monday, September 28, 2015 8:43 PM
To: Wells, Douglas P.; isotope-prod at jlab.org
Subject: Re: [Isotope-prod] Reminder VCU Talk Monday 11:30 CC F224-5

Thank you Douglas,

The practical conclusion for us would be then that we do not worry about other Cu isotopes, including 63Cu and 65Cu produced along with 67Cu, because there will always be much larger source of those in the target originally, and during the cycle of separation from different sources.

The dilution then becomes a characteristic to the whole process, and the processes should be optimized to achieve maximum SA. Would it help to run the non-irradiated target material through the separation process first several times to reach the equilibrium between Cu removal from the target material, and new Cu contamination coming back to the target material at the other stages of the process?

Did anyone consider the process of Gallium distillation at 2400C (boiling temp of Ga) with Ga evaporating from the mixture, and Cu staying (boils at 2562C).

Best regards,
Pavel

On 9/28/2015 6:47 PM, Wells, Douglas P. wrote:
I assume by “toxicity” you mean “dilution”?   Because dilution of the good-stuff (in this case, 67Cu) is usually the limiting factor toward utility.   I should start by saying that the answer that I got from City of Hope Hospital researchers in California may depend greatly on the kind of research one is doing.   For some of their research they wanted Specific Activity (SA) of approximately 20 Ci/g, while for other tissue-culture research they could live with an SA of 1 Ci/g.    These correspond to very roughly 1 67Cu atom per 10,000 – 100,000 other Cu atoms.

That sounds like a lot of stable Cu atoms.    Except EVERYTHING has Cu in it: your skin, the air, plastics, glassware, purified and enriched Ga targets, purified and Zn targets, water, everything.

And therein lies the challenge.   For people have known how to make 67Cu for a long time, and BNL has invested a considerable sum producing it, only to find that the final product was inconsistent in purity/SA quality and, therefore, unusable for large-scale research trials.

D

From: Isotope-prod [mailto:isotope-prod-bounces at jlab.org] On Behalf Of Pavel Degtiarenko
Sent: Monday, September 28, 2015 4:29 PM
To: isotope-prod at jlab.org<mailto:isotope-prod at jlab.org>
Subject: Re: [Isotope-prod] Reminder VCU Talk Monday 11:30 CC F224-5

Dear All,

Could anyone clarify to us the situation with the toxicity of Copper: what ratio of (Cu-63 + Cu-65) to Cu-67 atoms in the final product is too big, such that the product would become unacceptable.

We understand now that by making Cu-67 from Gallium, for example, the ratio could be done less than an order of few times, or even less than one. In case of Zinc target the ratio would be worse because the stable isotopes of Zinc are closer in both Z and A to stable Cu-63 and Cu-65 than the isotopes of Gallium. I guess this ratio would be enormous if Cu-67 is produced in Copper with double neutron captures on reactors.

In our conditions, without the initial Copper in the target, the ratio should stay rather limited, with the Gallium target having some advantage in that respect. Would that be good enough? What would be a hard limit on the ratio?

Best regards,
Pavel

On 9/28/2015 5:12 PM, Sundaresan Gobalakrishnan wrote:

Actinium-225 and Copper-67 are the first two products that we could initially try, due to their high medical relevance and in-house availability of related technologies for in vivo delivery in living subjects (in mice for now).

Best regards,
Sundaresan
On Sep 28, 2015 4:46 PM, "Wells, Douglas P." <Doug.Wells at sdsmt.edu><mailto:Doug.Wells at sdsmt.edu> wrote:
I wonder if, in the meantime - before the phone call is held, VCU can share with us the list of nuclear species that they are interested in?    We (SDSM&T) could look into photo-production of them if we knew what species are on their mind.

Thanks---D

-----Original Message-----
From: Isotope-prod [mailto:isotope-prod-bounces at jlab.org] On Behalf Of Sundaresan Gobalakrishnan
Sent: Monday, September 28, 2015 7:38 AM
To: George Neil; isotope production
Subject: Re: [Isotope-prod] Reminder VCU Talk Monday 11:30 CC F224-5

Dear George and All,

I regret to inform you that due to an emergency in Dr. Zweit's family, he will not be able to come and present his ideas at JLab today.

Once he returns to work, he will get in touch with you to reschedule his presentation.

Very sorry about any inconvenience this may cause.

Best regards,
Sundaresan

_____________________________________________
Sundaresan Gobalakrishnan, PhD
Assistant Professor
Center for Molecular Imaging, Department of Radiology Virginia Commonwealth University, Richmond, VA - 23298
Phone: 804-628-9165; Fax: 804-628-0223
E-mail: sundaresan.gobalakrishnan at vcuhealth.org<mailto:sundaresan.gobalakrishnan at vcuhealth.org>

-----Original Message-----
From: Isotope-prod [mailto:isotope-prod-bounces at jlab.org] On Behalf Of George Neil
Sent: Friday, September 25, 2015 11:39 AM
To: isotope production <isotope-prod at jlab.org><mailto:isotope-prod at jlab.org>
Subject: [Isotope-prod] Reminder VCU Talk Monday 11:30 CC F224-5

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