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At least 19 recordsLinked to original sources
PubMed1986

A new osmium-191/iridium-191m radionuclide generator system using activated carbon.

A new osmium-191/iridium-191m (191Os/191mIr) radionuclide generator system has been developed based on the absorption of K2OsCl6 (Os-IV) on 140-230 mesh heat-treated activated carbon. The generator is eluted with pH 2 saline solution containing 0.25 g/l Kl to give 191mIr in good yield. The generator eluent is neutralized to physiologic pH and isotonicity with Tris buffer immediately prior to i.v. injection. No scavenger column is required. As an example, elution of the prototype generator with a 2-ml bolus results in elution of 191mIr in approximately 18% yield with an 191Os breakthrough of only 2 X 10(-4)%/bolus. The prototype generator has consistent performance over a 2-wk period with no change in 191mIr yield or 191Os breakthrough. Loading of up to 1.5 Ci of 191Os results in no observed radiolysis. Continuous elution of this system is also possible with a mean 191mIr yield of 3.7%/ml and a mean 191Os breakthrough of 2 X 10(-5)%/ml at a flow rate of 12 ml/min. This new system represents a readily available source of 191mIr for radioangiography. Adsorbed radiation dose calculations indicate a total-body dose of only 3.9 mrad for a 100 mCi injected bolus.

Adsorption↗
PubMed1987

An osmium-191/iridium-191m radionuclide generator using an oxalato osmate parent complex.

A new osmium-191/iridium-191m (191Os/191mIr) radionuclide generator has been developed that offers high 191mIr yield (greater than 20%/ml) and low 191Os breakthrough (less than 5 X 10(-4)%/ml) when eluted with a solution of 0.001 M oxalic acid and 0.9% (normal) saline. This is the first 191Os/191mIr generator that combines the advantages of high 191mIr yield, extremely low 191Os breakthrough, and an eluate that does not require buffering prior to injection. These improvements in performance were accomplished through use of the chelate transdioxobisoxalatoosmate(VI) as the parent complex on the generator. The clinical result of the combination of higher yield and lower breakthrough is a 100-fold decrease in the estimated patient radiation dose compared with the same study performed with technetium-99m (99mTc), and the injectable eluate makes the generator easier to use. Acute and subacute toxicity studies performed on this generator eluate have shown no adverse effects attributable to the eluate.

Iridium↗
PubMed1992

Development of a high performance zinc-62/copper-62 radionuclide generator for positron emission tomography.

Clinical utilisation of positron emission tomography could be enhanced by the availability of short-lived radionuclides derived from generator systems. The zinc-62/copper-62 combination is one such system which could be used as a source for a number of copper-62 radiopharmaceuticals. We have developed and optimised a high activity (5.6 GBq, 150 mCi) zinc-62/copper-62 generator to provide 62Cu in a form that is suitable for direct labelling of pyruvaldehyde-bis-(N4-methylthiosemicarbazone)-copper(II), Cu(PTSM). The distribution coefficients of Zn(II) and Cu(II) between anion-exchange resin and various hydrochloric acid/organic solvent mixtures were measured. Based on these measurements a generator eluent of 0.3 M HCl/40% ethanol provided 62Cu in greater than 90% yield in a 3-ml volume. A very low 62Zn breakthrough of less than 3 x 10(-7)% was achieved. Copper-PTSM was successfully labelled with the no-carrier-added 62Cu eluent directly from the generator with 94% radiochemical yield.

Copper↗
PubMed1977

Microbial contamination of radionuclide generators.

Technetium-99m generators were grossly contaminted using 5 different strains of microorganisms. Elution of the generators showed that the number of microorganisms was reduced by a factor of 10(4)-10(6). There were no indications that the generators would support bacterial growth. It is concluded that it would be acceptable from a microbiologic point of view to omit autoclaving and membrane filtration of the final product provided that proper aseptic techniques are applied.

Bacteria↗
PubMed1989

Imaging positron emitting radionuclides generated during radiation therapy.

In vivo generated positron emitting radioisotopes, primarily C-11 and N-13, have been documented following therapy with accelerators larger than 10 MeV. Six patients had positron emission tomography 15 to 25 minutes after radiation therapy with a 42 MeV accelerator. Five patients had recurrent colorectal malignancy, and one required therapy for a carcinoma of the common bile duct. We sought to determine whether state-of-the-art PET technology could be used to monitor the three-dimensional activity distribution of radiation-induced radioactivity. At the time of the examination all six patients had sufficient concentrations of C-11 and N-13 activity in the irradiated volume to permit the evaluation of the activity distribution. We found significant activity at the body surface, which permitted field delineation. We conclude that the in vivo generated radioactivity can be monitored with PET.

Aged↗
PubMed1990

Copper-62-labeled pyruvaldehyde bis(N4-methylthiosemicarbazonato)copper(II): synthesis and evaluation as a positron emission tomography tracer for cerebral and myocardial perfusion.

Generator produced positron-emitting radionuclides could potentially expand the application of positron emission tomography (PET) to centers that do not have access to a local cyclotron. The zinc-62/copper-62 radionuclide generator system could serve as a source of positron-emitting copper-62 (62Cu) (t1/2 = 9.74 min) for physiologic imaging. Accordingly, we have prepared zinc-62/copper-62 generators capable of high output (greater than 300 mCi) and used the no-carrier-added eluate in a rapid high yield synthesis of [62Cu] Cu(PTSM) that provides the radiopharmaceutical in a form suitable for intravenous injection (where Cu(PTSM) = pyruvaldehyde bis(N4-methylthiosemicarbazonato) copper(II]. We then demonstrated in pilot studies that [62Cu]Cu(PTSM) provides high quality brain and heart images with PET, accurately delineating cerebral and myocardial perfusion in both experimental animals and in humans (corroborating results of previous experimental studies utilizing longer-lived copper isotopes). The results of this work demonstrate that 62Cu can be conveniently obtained from high-level generators and, when used to label Cu(PTSM), provides a generator-produced radiopharmaceutical capable of providing estimates of cerebral and myocardial perfusion independent of cyclotron-produced radionuclides.

Animals↗
PubMed1983

Gold-195m, an ultra-short-lived generator-produced radionuclide: clinical application in sequential first pass ventriculography.

Gold 195m (Au-195m) has a half-life of 30.5 sec and can be produced at the bedside from the parent mercury-195m (T 1/2 = 41.6 hr). The generator produced sterile pyrogen-free Au-195m with mercury breakthrough of 0.75 +/- 0.09 (s.e.m.) muCi per mCi of Au-195m. Approximately 20 to 25 mCi of Au-195m was produced per elution from a generator containing 155 mCi of Hg-195m. We compared first-pass resting Tc-99m angiograms with Au-195m angiograms in 28 patients. The correlation coefficient between the two studies was 0.92 over an ejection-fraction range from 0.22 to 0.83. In addition, we tested the reproducibility of Au-195m first-pass angiograms by performing two studies 3 min apart. In 25 patients with ejection fractions ranging from 0.20 to 0.78, the correlation coefficient between such pairs was 0.93. The nuclide is reliably and reproducibly produced, and its short half-life allows the performance of background-free sequential first-transit studies with unusually low radiation exposure to the patient.

Gold Radioisotopes↗
PubMed1977

An improved 191Os-191mIr generator for radionuclide angiocardiography.

191mIr is a useful tracer for radionuclide angiocardiography and may be of particular value in the evaluation of heart disease in children. It has a short half-life, a suitable photon energy, and may be obtained as a generator product by decay of its long-lived parent 191Os. A 191Os-191mIr generator capable of providing at least 18 mCi of 191mIr in 1.5 ml of eluant is described. 191mIr is separated from 191Os by absorbing 191OsCl6(-2) on an ion exchange resin and eluting with a solution of 8.7% NaCl at a pH of 2.2. The generator employs an additional resin column which is replaced to minimize 191Os breakthrough.

Animals↗