Production Of 123I Research Articles

Some technical improvements in the production of 123I via the [formula omitted] reaction at a compact cyclotron

Some technical improvements in the production of 123I via the 124 Te(p, 2n) 123I reaction are described. A target especially suited for use at compact cyclotrons was constructed, and the dry distillation of 123 I was optimized. The dependence of the loss of 124 TeO 2 as well as the 123 I-yield on the integrated beam current was determined. The radionuclidic purity of 123 I achieved experimentally in production runs using 124 TeO 2 targets of various isotopic enrichments is discussed.

Experiences in the routine production of123I via the124Te(p, 2n)123I reaction with a low energy cyclotron

Abstract This paper deals with the results and experimental observations obtained in routine production of123I via124Te(p, 2n)123I reaction, using the low energy cyclotron (protons, Emax=22 MeV) at the German Cancer Research Center in Heidelberg. The reaction was studied during the past 4 years using124TeO2 targets with various levels of enrichment. The purpose of the study was to determine which target material provided the highest quality and most economical production of123I. A viable routine production was defined as one in which123I could be conveniently and reproducably prepared in reasonable purity while maintaining a low cost for the entire process. Different methods of sublimation of123I activity from the124TeO2 target were examined to determine the optimal conditions for recovery of radioactivity and recycling of target material. A rapid method is described which permits quantitative separation of123I while allowing only a negligible loss of124TeO2.

Experiences in routine production of123I in Manitoba for delivery to other Canadian centres

An experience at123I production with a low beam current cyclotron used in combination with the124Te(p, 2n)123I reaction on 90.8% enrichment124Te is described.

123I production from radioxenon formed in spallation reactions by 660 MeV protons for medical research

Conditions of the 123I production from 123Xe, formed by irradiating thick targets with 660 MeV protons, are studied. The cross section of the 122Xe, 123Xe and 125Xe production have been determined in I, Cs, Ba and La targets for E p = 660 MeV. 123I yield and the contamination by 121I, 125I, 121Te and 119Te at irradiation of the CsCl melt (54g/cm 2) and the on-line Xe separation, have been determined by calculation and experimental methods.

Development of a process for routine production of123I using the127I(p, 5n)123Xe→123I reaction

The object of this paper is to give details of a production method for123I, now in routine use at Harwell. We employ the (p, 5n) reaction, irradiating a liquid target of di-iodomethane (CH2I2) spiked with additional iodine, with 58 MeV protons. A yield of ∼9 mCi/μAh is obtained; the only detectable radionuclidic impurity is125I, present to the extent of ∼0.15% by activity at the time of separation of Xe from I.

The Production of 123I and 84Rb at the University of Manitoba Cyclotron Laboratory

Production of 123I from the reaction 124Te(p,2n)123I is proceeding on a routine basis using a target similar to that developed at the A. V. F. cyclotron laboratory in Milan. It is believed that the current output may be sufficient to meet the Canadian need for thyroid scans at this time. The production of 84Rb has also recently been undertaken using the 84Kr(p,n)84Rb reaction on enriched 84Kr. The Rb is being used at St. Boniface General Hospital to trace blood flow patterns through the heart. Additional plans exist for the production of 81mRb from irradiation of natural krypton.

Routine Production of Iodine-123 at the Karlsruhe Isochronous Cyclotron

Routine, twice-weekly, preparation of iodine-123 with the Karlsruhe Isochronous Cyclotron is achieved by bombardment of thin highly enriched 124TeO2 (> 96 %) targets with protons of 26 MeV incident energy. This paper describes the experimental details of the targetry and radiochemical procedures have been in routine use at Karlsruhe for production and separation of 123I for two years.

Yield curves for cyclotron production of 123I, 125I and 121I by 127I (p, xn) Xe → ( β) → I reactions

Absolute yields for the reactions 127I(p, xn)Xe: x = 3,5,7 in the range 20–160 MeV have been measured by the activation method. Subsidiary measurements of the half-lives of xenon products and the abundance of gamma rays in 121Xe decay are also reported. Thick target yield curves calculated from these results are compared with existing data. These curves allow prediction of the possible yields and isotopic purity of the medically important isotope 123I produced by the spallation reaction 127 I( p,5 n) 123 Xe → (β) → 123 I .

In beam collection of 123Xe for carrier-free 123I production

Preparation of 123I from the 127I( p, 5n 123Xe reaction at the Grenoble cyclotron and medical use at the Nuclear Medicine Centre in Lyons has already been described. (5,6) Here we deal with the improvement of the Xe recuperation yield leading to the development of a continuous gas flow system using liquid iodine and isolating 123Xe during the bombardment. We show that 123I yield can be enhanced and the whole system automatized, reducing the irradiation hazards to personnel. The system developed so far must be regarded as a prototype open to improvement.

Cyclotron isotopes and radiopharmaceuticals—XXII. Improved targetry and radiochemistry for production of 123I and 124I

An improved 4 π water-cooled target for production of 123I of >99.4% radionuclidic purity via the 124Te( p,2 n) 123I reaction with 25.8-MeV protons on 256 mg cm −2 124Te of >99.8% isotopic enrichment is described. Radiochemical methods and results for obtaining 123I as iodide by sorption techniques, and a quantitative procedure for recovery (99.8 ± 0.2%) of the ultrahigh enrichment 124Te are described. The methods are applicable to 124I production if the incident proton beam is reduced to 12 MeV. Optimized thick target production yields for 123I and 10.6 and 0.093 mCi μAh −1, respectively.

A multi-target assembly in an irradiation with high energy particles. Simultaneous production of 123I, 62Zn and 13NH 3

A multi-target assembly in an irradiation with high energy particles. Simultaneous production of 123I, 62Zn and 13NH 3

Production of 123I by alpha and 3He irradiation of natural tellurium

In order to determine the optimum irradiation condition to produce 123I for nuclear medical use, excitation curves and thick-target yield curves were measured by means of stacked foil technique for alpha and 3He reactions producing 123Xe, 123I, 125Xe and 130I, both from natural tellurium. The 123Xe yields from natural tellurium are too low for routine production. However, by bombarding 76.5% isotopically enriched 123Te target with 30MeV 3He particles, 724 micronCi/micronAh of 123I would be obtained, whereas the level of 125I contaminat would be about 0.14%. 130Te contaminant in enriched 123Te target produces 130I alpha and 3He bombardment, although it has not been reported in the past. The 130I contaminant can be easily eliminated.

Large scale production of 123I from a flowingliquid target using the ( p,5n) reaction

Methods have been developed for production of 123I by decay of 123Xe formed by the reaction 127I( p, 5 n) 123Xe, by bombarding a flowing target of CH 2I 2/I 2 with a current of 10–20 μA of 58 MeV protons produced by the Harwell Variable Energy Cyclotron. At this high current, radiation chemical reactions which are dose rate and total dose dependent caused serious difficulties, and means of overcoming these are reported. A practical production rate (which includes all losses during irradiation, trapping and chemical washing-out of the trap) of 5–6 mCi/μAhr has been achieved. The only impurity found is 125I, present to the extent of 0.13% by activity. A total of 107 patients have been treated with pharmaceuticals labelled with ∼2 Ci of 123I produced in 20 separate runs.

Production of123I and28Mg by high-energy nuclear reactions for applications in life sciences

The advantages of high energy cyclotrons as compared to small compact cyclotrons for the production of special radionuclides are outlined. The routine production of123I (T=13.3 h) and28Mg (T=21.1 h) by means of high energy nuclear reactions at the Julich Isochronous Cyclotron is described. The reaction127I(d,6n)123 $$Xe\xrightarrow{{\beta ^ + ,EC}}$$ 123I at 78 to 64 MeV is used for the production of123I with thick target yields of 8 mCi/μAh and high radionuclidic purity. The practical experience in the application of this process, which is well suited for the production of Na123I and for123Xe-exposure labelling techniques, is reported.28Mg is produced by the27Al(α, 3p)28Mg reaction at Eα=140 to 30 MeV with thick target yields of 40 μCi/μAh. The carrier-free28Mg is separated from the matrix activities by coprecipitation and anion exchange with chemical yields of 80%.

123I production at the Milan AVF cyclotron

The production of123I from enriched124Te is described. Preliminary experiments on a distillation separation of iodine from the Te target have been performed and the method seems promising in comparison to the time-consuming chemical separation technique.

Excitation functions and yields for 123I production using the 127I( p, 5 n) 123Xe reaction

Excitation functions and yields are described for 123I production via the 127 I(p, 5n) 123 Xe ▪ 123 I reaction. The 123Xe and 125Xe excitation functions were determined experimentally by irradiating thin (2 MeV thick) 127I targets at the Crocker Nuclear Laboratory. The 123Xe excitation function is used to obtain 123Xe yield as a function of target thickness for commonly used target materials and for different incident proton energies. These results indicate that yields of several curies per hour of 123Xe are possible using a 10μA proton beam. Radio-chemical impurities were measured and found to be small.

Production of short-lived radioisotopes for medical applications using high-energy reactions at JULIC.

The advantages of high energy nuclear reactions for the production of some special short-lived carrier-free radionuclides for allication in nuclear medicine are outlined. The routine production of 11C (T = 20.3 min), 123I (T = 13.3 h) and 28Mg (T = 21.1 h) at the Julich Isochronous Cyclotron JULIC via the 12C(p,pn) 11C-, 127I(d,6n) 123Xe(beta+, EC) 123I- and 27Al(alpha,3p) 28Mg-reaction, respectively, is described. Some areas of fast labelling and its applications are given.

Production of 123I for medical purposes at the Milan AVF cyclotron

A method is described for the production of large quantities of 123I by exciting a ( p, 2 n) reaction on enriched 124Te targets. Results are presented for the relevant excitation functions. The irradiation technique and the chemical processes used in the separation of 123I and the recovery of the target material are described in some detail.

Production of 123I via the 127I(d,6n) 123Xe(β +,EC) 123I process

The bombardment of iodine with about 70 MeV deuterons can be conveniently used for routine production of 123I ( T = 13·3 hr) for nuclear medical applications. Excitation functions of the relevant 127I(d,xn) and 127I(d,pxn) reactions have been determined by means of the stack-foil technique within the energy range from 10 to 90 MeV. The cross section of the 127I(d,6n) 123Xe-process has a flat maximum with σ = 300 mb at a deuteron energy of 69 MeV. A thick NaI-gas flow target has been developed which allows a continuous removal of the 123Xe-parent with an efficiency of about 80 per cent, allowing the production of 123I with a thick target yield of 8mCi/μAh at an 125I-impurity level of ≤0·2 per cent.

Note on the production of 123 I for radiodiagnostical purposes.

Note on the production of 123 I for radiodiagnostical purposes.