Progress of photonuclear cross sections for medical radioisotope production at the SLEGS energy domain

Photonuclear reactions using a laser Compton scattering(LCS)gamma source provide a new method for producing radioisotopes for medical applications.Compared with the conventional method,this method has the advantages of a high specific activity and less heat.Initiated by the Shanghai Laser Electron Gamma Source(SLEGS),we conducted a survey of potential photonuclear reactions,(γ,n),(γ,p),and(γ,γ')whose cross sections can be measured at SLEGS by summarising the experimental progress.In general,the data are rare and occasionally inconsistent.Therefore,theoretical calculations are often used to evaluate the production of medical radioisotopes.Subsequently,we verified the model uncertainties of the widely used reaction code TALYS-1.96,using the experimental data of the^(100)Mo(γ,n)^(99)Mo,^(65)Cu(γ,n)^(64)Cu,and^(68)Zn(γ,p)^(67)Cu reactions.

Accurate Formulae for the Cross-Section Data for the Radio-Halogen I-123 from Cyclotron Production

123I is the most widely used cyclotron-produced radio-halogen in medical research. In this paper, excitation function formulae for the nuclear reactions of 123I production are introduced. 124Te (p, 2n)123I and 127I (p, 5n)123Xe → 123I nuclear reactions have been studied as a function of the energy of the neutrons. Both two formulae were created using the least squares regression of the experimental cross sections data, which were obtained from the Experimental Nuclear Reaction Data EXFOR Database version of 2023. The proposed formulae were evaluated using two statistical indicators for goodness-of-fit. High agreement was observed between the empirical and experimental results for both nuclear processes.

乳糖化修饰纳米基因载体的肝靶向性研究(英文)

Objective:To compare the targeting effects of lactosarninated alginate(AlgNP)、polyethylene glycol - coated hydroxyapatite- poly- L- lysine nanoparticles (PLL- PCHNP)and relative nonlactosaminated ones load ed with exogenous gene on liver via peripheral intravenous route. Methods:Preparation of AlgNP based on control of gelification phenomenon of algiante by calcium ions and HA- PLLNP with collosol - gel method, both further modified with lactosaminated - poly- L - lysine synthesized by reductive lactosamination . We used pEGFPCl as the reporter gene to establish receptor- mediated and positive liver targeting nanoparticles- gene model. The potential of adsorbing DNA on nanoparticles was analysed by electrophoresis and spectrophotometer. Then different complexes were transferred into the rat's body by peripheral intravenous route and their targeting characteristics in liver were investigated by using radioisotope tracing assay. Results: PCHNP presented as needle - like particles with a diameter of 20nm by TEM and could be effectively combined with PLL. The diameter of AlgNP was 280nm. Agarpse gel electrophoresis showed both nanoparticles could effectively combine with DNA and the optimal proportion of PLLPCHNP and DNA was 30:1 (w/w); DNA mixed ratio of AlgPLL was 68.3 % by spectrophotometer. The radioactivities in liver for the two lactosaminated nanoparticles were higher than the nonlactosaminated ones. No statistic difference between AlgNP and AlgLacNP could be found . Conclusions: Lactosaminated naroparticles can target to liver more effectively by peripheral intravenous route than nonlactosaminated ones, which is closely concerned with the characteritics of the nanopartide complex.

Serial stimulated thyroglobulin measurements are more specific for detecting distant metastatic differentiated thyroid cancer before radioiodine therapy

Objective: Preablative stimulated thyroglobulin (ps-Tg) has the potential to be used in identifying distant metastatic differentiated thyroid carcinoma (DM-DTC), but its single level can be affected by remnant thyroid tissue and thyrotropin (TSH). The objective of this retrospective study was to evaluate the value of serial ps-Tg measurements in identifying DM-DTC specifically. Methods: A total of 317 DTC patients with serial measurements of ps-Tg, TSH and anti-Tg antibody were divided into M1 (n=72) and M0 (n=245) according to the presence of distant metastasis (DM) or not. The initial psTg measurement, with a corresponding TSH exceeding 30 mu IU/mL, was marked as Tg1, and ps-Tg measured right before radioactive iodine (RAI) therapy was defined as Tg2, with a median interval of 8 days. Delta Tg denotes Tg2-Tg1, and Delta TSH denotes TSH2-TSH1. Tg1, Tg2, Delta Tg, and Delta Tg/Delta TSH were tested for efficacy in identifying DM-DTC using receiver operating characteristic (ROC) curve analysis, and further compared with chest computed tomography (CT) and posttreatment whole-body RAI scan (RxWBS). Results: Compared with single ps-Tg measurement (Tg1 or Tg2), both Delta Tg and Delta Tg/Delta TSH were more narrowly distributed around zero in the M0 group, which made their distribution in the M1 group more distinguished in a relatively dispersed way. Delta Tg/Delta TSH manifested a higher accuracy (88.64%) and specificity (90.20%) in identifying DM-DTC than Tg1 or Tg2 measurements, with a much higher specificity than chest CT (90.20% vs. 66.00%) and a much higher sensitivity than RxWBS (83.33% vs. 61.11%). Conclusions: Serial ps-Tg measurements even over as short an interval as 8 days hold incremental value in identifying DM-DTC. Delta Tg/Delta TSH is a specific early biochemical marker for DM-DTC.

Treatment of portal vein tumor thrombus using ^(125)Iodine seed implantation brachytherapy

We reported two cases of liver metastasis with portal vein tumor thrombus that developed after liver transplantation for hepato cellular carcinoma (HCC). Both the patients were women aged 43 and 55 years, who had liver metastasis and portal vein tumor thrombus formation after liver transplantations for HCC. For the treatment of portal vein tumor thrombus, 125I seeds were implanted into the hepatic tissue under the guidance of preoperative computed tomography (CT) images with a total radiation dose of 130 Gy. Enhanced spiral CT scan was performed for evaluation of the liver at 12 and 16 wk after treatment. Thereafter, upper abdominal CT examination was performed every 2-3 mo. No severe complications associated with the 125I seeds were seen in these two patients. The upper abdominal CT images (obtained after 3 and 4 mo of treatment) showed that the thrombosis reactions were complete reaction and restoration of the patency of the partially obstructed portal vein with partial obstruction. In the case with complete obstruction of the portal vein, the thrombosis was resolved completely, but blood flow could not be restored. After this treatment, one of the patients is stillalive, while the other died within 6 mo after the treatment due to lung metastasis complicated with lung infection, leading to respiratory failure.

Baculovirus vector-mediated transfer of NIS gene into colon tumor cells for radionuclide therapy

AIM:To investigate the feasibility of radionuclide therapy of colon tumor cells by baculovirus vector-mediated transfer of the sodium/iodide symporter(NIS) gene.METHODS:A recombinant baculovirus plasmid carrying the NIS gene was constructed,and the viruses(BacNIS) were prepared using the Bac-to-Bac system.The infection efficiency in the colon cancer cell line SW1116 of a green fluorescent protein(GFP) expressing baculovirus(Bac-GFP) at different multiplicities of infection(MOI) with various concentrations of sodium butyrate was determined by flow cytometry.An in vitro cytotoxicity assay was also conducted after infection of SW1116 cells with Bac-NIS.Iodine uptake of Bac-NIS infected SW1116 cells and inhibition of this uptake by sodium perchlorate was examined,and the effect of Bac-NISmediated 131 I in killing tumor cells was evaluated by cell colony formation tests.RESULTS:Infection and transgene expression in SW1116with Bac-GFP were significantly enhanced by sodium butyrate,as up to 72% of SW1116 cells were infected with the virus at MOI of 400 and sodium butyrate at 0.5 mmol/L.No obvious cytotoxicity was observed under these conditions.Infection of SW1116 with Bac-NIS allowed uptake of 131 I in these tumor cells,which could be inhibited by sodium perchlorate.The viability of SW1116 cells infected with Bac-NIS was significantly lower than with Bac-GFP,suggesting that NIS gene-mediated 131 I uptake could specifically kill tumor cells.CONCLUSION:Baculovirus vector-mediated NIS gene therapy is a potential approach for treatment of colon cancer.

Distribution and Accumulation of Neodymium and Its Effect on Secretion of Progesterone in Mice

Distribution and accumulation of Nd, and its effect on secretion of progesterone in mice were studied using radioisotope tracer ((()^(147)Nd)) technique. Following single intraperitoneal administration of neodymium traced with (()^(147)Nd) at a dose of 200 mg·kg^(-1), uneven distribution of the radioactive Nd occurred in various tissues and organs. Much amount of (()^(147)Nd) accumulates in the bone, and the residue increases with the lapse of time. Some amount of radioactivity was also detected in eyes, blood and brain, but the accumulation decreased with the time due to excretion and re-distribution in mice. In comparison with controls, concentration of progesterone is found to be significantly lower in the serum of administered mice, indicating a significantly inhibitory effect of Nd on secretion of progesterone.

Investigation of production of medical ^(82)Sr and ^(68)Ge for ^(82)Sr/^(82)Rb and ^(68)Ge/^(68)Ga generators via proton accelerator

How to operate^(82)Sr/^(82)Rb and ^(68)Ge/^(68)Ga generators used in the positron emission tomography scan process is explained, and the importance of ^(82)Sr and ^(68)Ge radionuclides for these generators is revealed. To produce medical ^(82)Sr and ^(68)Ge by means of a proton accelerator in an irradiation time of 24 h, a proton beam current of250 l A, and an energy range E_(proton)= 100 →5 MeV, the cross sections and the neutron emission spectrum curves of(p,xn) reaction processes on Rb-85, Ga-69 and Ga-71 targets were calculated, and the activities and yields of the product were simulated for the reaction processes. Additionally, the integral yields of the reaction processes were determined via the calculated cross-sectional curves and the mass stopping power obtained from the X-PMSP program. Furthermore, based on the obtained results, the appropriate reaction processes for the production of ^(82)Sr and ^(68)Ge isotopes on Rb-85, Ga-69, and Ga-71 targets are discussed.

Exploratory study of betavoltaic battery using ZnO as the energy converting material

Third-generation-semiconductor zinc oxide is utilized as an energy converting material in a betavoltaic battery, where 0.06 Ci^(63) Ni and 8 Ci^(147) Pm are used as the beta sources. Based on a Monte Carlo simulation, the full scales of the devices are derived as 17 and 118 lm,respectively, for both sources. The influences of semiconductor doping concentrations on the electrical properties of the devices are analyzed. For a typical doping concentration N_A= 10^(17) cm^(-3), N_D= 10^(16) cm^(-3), the conversion efficiencies are 7.177% and 1.658%, respectively, using63 Ni and147 Pm sources. The calculation results of energy deposition in materials for the two sources show that the doping concentrations drop to 1 × 10^(13)–5×10^(14) cm^(-3) and 1 × 10^(12)–5×10^(13), and accordingly, the energy conversion efficiencies rise to 14.212% and 18.359%, respectively.

Tc-99m ciprofloxacin imaging in diagnosis of chronic bacterial prostatitis

Aim: To investigate the value of Tc-99m ciprofloxacin imaging in the differential diagnosis of chronic bacterial prostatitis. Methods: The study included 4 normal subjects as the negative controls, 2 patients with acute prostatitis or cystourethritis as the positive controls and 59 patients diagnosed as chronic bacterial prostatitis or chronic pelvic pain syndrome by traditional laboratory tests. In every subject, the single photon emission computerized tomography images were obtained 3 h after intravenous injection of Tc-99m Ciprofloxacin. The results of the imaging were compared with those of laboratory tests. Results: On the images, negative uptake was observed in all normal subjects, while strong hot uptake, in the whole prostate of acute prostatitis patients and in the whole urethra of acute cystourethritis patients. In 13 (68 %) of 19 patients categorized as chronic bacterial prostatitis by standard laboratory tests, hot uptake with less intensity than that of acute prostatitis was observed in the prostate area around the prostatic urethra. Negative uptake in the prostate was observed in 6 of 19 patients (32 %) categorized as chronic bacterial prostatitis. Interestingly, hot uptake in the prostate was exhibited in 28 (70 %) of the 40 patients categorized as chronic pelvic pain syndrome. Conclusion: Tc-99m ciprofloxacin imaging is helpful in the differential diagnosis of prostatitis syndrome.

Man-made plutonium radioisotopes in the salt lakes of the Crimean peninsula

Investigations of ^(239+240)Pu and ^(238)Pu in the surface layer(0–5 cm) of bottom sediment in the Crimean 10 salt lakes from 4 geographical groups were carried out for the first time. The ^(239+240)Pu varied widely between regional geographical groups of lakes as well as within groups too and ranged from 11±4 to 451±43 mBq^(239+240)Pu/kg. The highest levels of ^(239+240)Pu—419±27, 443±24 and 451±43 mBq/kg were observed in the Yevpatoriya(Lake Kyzyl-Yar), the Tarkhankut(Dzharylhach) and the Kerch group(Tobechik), respectively. The lowest values of ^(239+240)Pu were identified in three lakes of the Perekop group and were 20±12, 24±6 and 48±6 mBq/kg. In all lakes ^(238)Pu was an order of magnitude lower than 239+240 Pu and varied from 4.8±2.6 to 30.7±5.5 mBq/kg. The ^(238)Pu activity was decay-corrected to 1986. The characteristic ratio of the ^(238)Pu/239+240 Pu activities in the sediment and percentage of the Chernobyl-derived Pu was calculated. The largest percentages of the Chernobyl-derived Pu were observed in the Evpatoriya group(Lake SasykSivash)—16.2%±8.26%, the Tarkhankut group(Dzharylhach)—8.4%±2.10% and the Kerch group(Aktash)—10.5%±5.56%. The study of the depth distribution of plutonium in the Lake Kyzyl-Yar bottom sediment core(0–25 cm) was fulfilled. It was shown that 239+240 Pu was high enough in all studied layers of bottom sediment, but the highest activity ratio ^(238)Pu/239+240 Pu(0.062±0.020) was found in the deepest layer of 15–20.5 cm and the percentage of Chernobyl-derived Pu was estimated at 6.8%±2.85% in this layer.

Innovative Use of Light-Weight Radioisotopes in Therapeutics and the Engineering of Light-Power Generators

Light weight radioisotope (LWR) 89Sr and 90Sr could be obtained from used rods in fission atomic plants. The economics of the disposal of nuclear bars indicate the convenience to develop added value applications. The difference in t1/2 allows 89Sr to deliver its energy at a rate 200 times higher than 90Sr. A large emission number of low penetrating power particles in a short time characterize 89Sr, which allows that these highly radioactive LWR involves a rather limited danger. Chemical similitude of calcium and strontium uptake has led to the use of 89Sr in treatment of bone cancer metastasis. 89Sr damages animal tissues because ionize water, but penetrates through the skin about: 5 to 8 mm. Hence, to obtain it in insoluble form, like obtaining 89Sr silicate, could make possible its wider use. Purifying 89Sr from contaminant 90Sr allows that after one year do not leave any contamination. LWR could be covered with scintillators substances, which by subtracting kinetic energy from beta-radiation, emit light and function as a major source of shielding. This treatment engineers Radioisotope Light Generators (RLG). Their light could activate photovoltaic cells (PV), which could lead to nano-devices without moving parts RLG-PV.

Simulating the Production of Medical Radioisotopes in a Fast Thorium-Cycle ADS with SERPENT

Radiopharmaceuticals are used in nuclear medicine for diagnostic or therapeutic acts. The short decay half-lives of medical radioisotopes, especially those used for diagnostics, imply that they should be produced continuously and transported as quickly as possible to the medical units where they are used. Neutron-rich medical radioisotopes are generally produced in research reactors, like technetium-99m, lutetium-177, holmium-166 and iodine-131. On the other hand, proton-rich radioisotopes are produced via reactions with charged particles from accelerators like fluorine-18, gallium-67, iodine-123 and thallium-201. Beside this, innovative nuclear reactors are advocated as solutions to the issues of nuclear waste production and proliferation threats. Fast neutron, thorium-cycle and accelerator-driven subcritical (ADS) reactors are some of the most promising of them, proposed as safer fuel breeders and “waste burners”. This article examines the use of a fast thorium-cycle ADS with liquid lead-bismuth eutectic coolant for the production of molybdenum-99/technetium-99m and lutetium-177. Burnup simulation has been made with the Monte-Carlo (MC) code SERPENT. It is demonstrated that MC codes can advantageously be used to determine the optimal irradiation time for a given radioisotope in a realistic reactor core. It is also shown that fast thorium-cycle ADS is an economical option for the production of medical radioisotopes.

INVESTIGATIONS OF NATURAL AND ARTIFICIAL RADIOACTIVE ISOTOPES IN SEAWATER AND SEDIMENTS IN THE YELLOW SEA AND ADJACENT SOUTHEAST AREA

Investigations of natural and artificial radioisotopes including 90Sr,137Cs, gross B and U carried out in the Yellow Sea and adjacent southeast area in 1963. 1964, 1975 and 1978 showed that radioactive pollution by 90Sr and 137Cs from atmospheric fallout had gradually decreased with time due to the cessation of atmospheric nuclear weapons tests in the 70s. The distributions of natural and artificial radioactive isotopes (U, Ra, Th. 40K and 137Cs) in sediments southwest of Jizhou Island were uniform. The more uniform may be related to the soluble species of U[Uo2(CO3)4] in the seawater.The high value of Th at stations 3 and 6 was related to the sandy clay sediment; the low value at station 8 was related to sandy sediment. The content of 137Cs in the eddy area being less than about half of that in the China inshore area showed that the source of Cs may be insufficient orthat the conditions for enriching " Cs in the circulation eddy area were not favorable.

Internal radiation therapy:a neglected aspect of nuclear medicine in the molecular era

With increasing evidence, internal radiation therapy, also known as brachytherapy, has become a neglected aspect of nuclear medicine in the molecular era. In this paper, recent developments regarding internal radiation ther- apy, including developments in radioiodine-13l （131^I） and thyroid, radioimmunotherapy （RIT） for non-Hodgkin lym- phoma （NHL）, and radiopharmaceuticals for bone metastases. Relevant differences and status of their applications in China were mentioned as well. These molecular mediated internal radiation therapies are gaining increasing importance by providing palliative and curative treatments for an increasing number of diseases and becoming one of the important parts of molecular nuclear medicine.

Model-based cross section calculations on production of 43,34Sc,45Ti, 51Cr, 54Mn, and 55Fe radioisotopes

A cross section database on excitation functions of reactions produced by charged particles is essential for many areas of nuclear research. Particularly, accurate knowledge on nuclear cross sections for the cyclotron production of radioisotopes is very important for nuclear medicine. In the present paper, the cross section calculations for the production of^(43),^(34)Sc,^(45)Ti,^(51)Cr,^(54)Mn, and^(55) Fe radioisotopes were carried out by the use of ALICE/ASH code using the Fermi gas model, Kataria Ramamurthy Fermi gas model, and superfluid nuclear model for nuclear level density. Thereby, these model calculations were compared with the available measured data.

Influence of four kinds of polysaccharides on the induction of lymphokine-activated killer cells in vitro

Effects of Lycium barbarum polysaccharide（LBP）,Astragalus polysaccharide（APS）,polysaccharide of Acanthopanax senticosus（PAS）and polysaccharide of bacteriallipopolysaccharide（PS）on the induction of lymphokine-activated killer（LAK）cells fromC57BL/6 murine splenocytes were studied using [125I]UdR release assay.The fourpolysaccharides alone were shown to induce no cytotoxicity.When combined with humanrecombination interleukin-2（rlL-2）,they augmented LAK cell activities in adose-dependent manner,most markedly at 0.01～0.1 mg·ml-1for LBP,0.01 mg·ml-1 forAPS and PAS,and 0.01 μg·ml-1 for PS.They increased LAK cell activity in a shortrange of rIL-2 concentrations(250～1000U·ml-1).They were shown to inhibit LAK cellactivity when used beyond the suitable dosage.

Tumour Localization of A Mitomycin C-Monoclonal Antibody MGb_2 Conjugate in Nude Mice with Human Gastric Carcinoma Xenografts

MGb2 is a monoclonal antibody againstgastric cancer.It can be well localized in thetumour tissue and has been successfully used inthe radioimmunoimaging in the patients withgastric cancer.The conjugate of MGb2 withchemotherapeutic drug mitomycin C（MMC）al-so shows highly selective cytotoxic effect uponhuman gastric cancer cells in vitro.

Tumor localization of anti-gastric cancer monoclonal antibody MGb_2-daunomycin conjugate in nude mice bearing human gastric carcinoma SGC-7901

In the present study,an anti-gastric cancer monoclonal antibody MGb2-daunomycin（DM）conjugate was prepared by cis-aconitic anhydride method.The distribution of the conjugatein nude mice bearing human gastric carcinoma SGC-7901 was investigated.Four to five moleculesof DM were introduced into each molecule of antibody while the antigen-binding capacity ofthe antibody was well-retained.This conjugate could be satisfactorily localized in the tumortissue.Ninety-six hours after intraperitoneal injection of 125I-MGb2-DM conjugate,the ratio ofradioactivity per milligram of tumor to that per milligram of blood reached 203,the result beingquite similar to that of unmodified MGb2.

Evaluation of Excitation Functions of Reactions Used in Production of Some Medical Radioisotopes

In this work, reaction cross-sections were calculated and Excitation Functions were evaluated for productions of 208Bi, 212,211,210At, 211,210Po isotopes using EXIFON code in the energy range from 0 MeV to 30 MeV. The code is based on an analytical model for statistical multistep direct and multistep compound reactions (SMD/SMC model). This work also investigates the shell structure effect on the reaction cross-section, the results obtained show that the cross-sections of (a, na) reaction for both with shell correction and without shell correction are zeros at energies range considered, this shows that the energy of the incident particle is below the threshold of this reaction due to the present of coulomb repulsive force between the projectile and target nucleus.