Production of Medical Radioisotopes with High Specific Activity in Photonuclear Reactions with γ\gamma Beams of High Intensity and Large Brilliance

We study the production of radioisotopes for nuclear medicine in $(\gamma,x{\rm n}+y{\rm p})$ photonuclear reactions or ($\gamma,\gamma'$) photoexcitation reactions with high flux [($10^{13}-10^{15}$)$\gamma$/s], small diameter $\sim (100 \, \mu$m$)^2$ and small band width ($\Delta E/E \approx 10^{-3}-10^{-4}$) $\gamma$ beams produced by Compton back-scattering of laser light from relativistic brilliant electron beams. We compare them to (ion,$x$n$+ y$p) reactions with (ion=p,d,$\alpha$) from particle accelerators like cyclotrons and (n,$\gamma$) or (n,f) reactions from nuclear reactors. For photonuclear reactions with a narrow $\gamma$ beam the energy deposition in the target can be managed by using a stack of thin target foils or wires, hence avoiding direct stopping of the Compton and pair electrons (positrons). $(\gamma,\gamma')$ isomer production via specially selected $\gamma$ cascades allows to produce high specific activity in multiple excitations, where no back-pumping of the isomer to the ground state occurs. We discuss in detail many specific radioisotopes for diagnostics and therapy applications. Photonuclear reactions with $\gamma$ beams allow to produce certain radioisotopes, e.g. $^{47}$Sc, $^{44}$Ti, $^{67}$Cu, $^{103}$Pd, $^{117m}$Sn, $^{169}$Er, $^{195m}$Pt or $^{225}$Ac, with higher specific activity and/or more economically than with classical methods. This will open the way for completely new clinical applications of radioisotopes. For example $^{195m}$Pt could be used to verify the patient's response to chemotherapy with platinum compounds before a complete treatment is performed. Also innovative isotopes like $^{47}$Sc, $^{67}$Cu and $^{225}$Ac could be produced for the first time in sufficient quantities for large-scale application in targeted radionuclide therapy.Comment: submitted to Appl. Phys.

Incorporation of radiohalogens via versatile organometallic reactions: applications in radiopharmaceutical chemistry

Factors that must be considered for the design of radiohalogenated radio-pharmaceuticals include the stability and availability of the substrate, the physical half-life of the radiohalogen and the in vivo stability of the radiolabel. Vinyl and phenyl radiohalogen bonds show more in vivo stability than the alkyl radiohalogen bonds. Consequently, a variety of methods suitable for the synthesis of tissue specific radiopharmaceuticals bearing a vinyl or phenyl radiohalogen have been developed involving the synthesis and halogenation of metallovinyl and phenyl intermediates. The halogens and metallation reactions include iodine and bromine and alanation, boronation, mercuration, stannylation, and thallation, respectively. 19 refs., 1 fig., 1 tab

Availability of rhenium-188 from the alumina-based tungsten-188/Rhenium-188 generator for preparation of rhenium-188-labeled radiopharmaceuticals for cancer treatment

Rhenium-188 (β- = 2.2 MeV; γ- = 155 keV; T(1/2) 16.9 hours) is an attractive therapeutic radioisotope which is produced from decay of the reactor-produced tungsten-188 parent (T1/2 69 days) and thus conveniently obtained on demand by elution from the alumina-based tungsten-188/rhenium-188 generator system. The rhenium-188 is obtained as sodium perrhenate by elution of the generator with 0.9% saline. The post elution use of disposable tandem, ion-exchange columns is a simple method for the concentration of rhenium-188 saline solutions with specific volumes > 500 mCi/ml. This method can also extend the useful shelf-life of the generator, which can be as long as one year. The long useful shelf-life of the generator is expected to provide rhenium-188 at very reasonable costs for routine preparation of a variety of radiopharmaceuticals for the treatment of a variety of cancers

Nuclear medicine program progress report for quarter ending December 31, 1991

This report presents information on (1) a new improved synthesis of carrier-free rhenium-188-labeled Re(V) dimercaptosuccinic acid (DMSA) complex as a potential therapeutic agent for treatment of thyroid medullary carcinoma; and (2) the synthesis and evaluation of a series of iodine-125-labeled analogues of altanserine for imaging of serotonin receptors

Metabolites of IPPA, BMIPP, and DMIPP fatty acids in rats hearts: A quantitative HPLC-study

The significance of the use of radioiodinated fatty acid analogues such as 15-(p-iodophenyl) pentadecanoic acid (IPPA), 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP), and 15-(p-iodophenyl)-3-dimethylpentadecanoic acid (DMIPP) for the evaluation of regional myocardial fatty acid uptake is well documented. An understanding of the relative incorporation of these fatty acid analogues into various fatty acid pools is important to correlate fatty acid uptake and release with flux through the various metabolic pathways. While the free fatty acid (FFA) pool is immediately available for oxidation to meet energy demands for contraction under normoxic conditions, the FFA are also stored as triglycerides (TG) for oxidation at a later period. Although the incorporation of IPPA, BMIPP, and DMIPP into the major phospholipid classes has not been previously investigated, demonstration of the incorporation of IPPA and BMIPP into phospholipids would be important as further evidence that these modified'' fatty acids are, at least qualitatively, metabolized through the usual metabolic pathways. The goals of the present studies were thus to develop the necessary HPLC techniques and evaluate the incorporation of IPPA, BMIPP, and DMIPP into complex endogenous lipids in dual label studies. 2 refs., 6 figs