212Pb: Production Approaches and Targeted Therapy Applications

Over the last decade, targeted alpha therapy has demonstrated its high effectiveness in treating various oncological diseases. Lead-212, with a convenient half-life of 10.64 h, and daughter alpha-emitter short-lived 212Bi (T1/2 = 1 h), provides the possibility for the synthesis and purification of complex radiopharmaceuticals with minimum loss of radioactivity during preparation. As a benefit for clinical implementation, it can be milked from a radionuclide generator in different ways. The main approaches applied for these purposes are considered and described in this review, including chromatographic, solution, and other techniques to isolate 212Pb from its parent radionuclide. Furthermore, molecules used for lead’s binding and radiochemical features of preparation and stability of compounds labeled with 212Pb are discussed. The results of preclinical studies with an estimation of therapeutic and tolerant doses as well as recently initiated clinical trials of targeted radiopharmaceuticals are presented.

In-situ assessment of natural terrestrial-radioactivity from Uranium-238 (238U), Thorium-232 (232Th) and Potassium-40 (40K) in coastal urban-environment and its possible health implications

The risk of natural terrestrial radioactivity on human health is often underestimated, and environmental safety awareness is necessary. Hence, this study aims to assess natural sources of gamma radiation emitter in coastal urban-environment using the radiometric technique. The dosage of gamma radiation from a parent radionuclide such as Uranium-238 (238U), Thorium-232 (232Th) and Potassium-40 (40K) and were measured using portable gamma spectroscopy. The result showed that the measured value of 238U activity was between 10.81 $$\pm$$ ± 0.69 and 46.31 $$\pm$$ ± 1.43 Bqkg−1. The mean value was estimated to be 35.44 $$\pm$$ ± 0.97 Bqkg−1 which is slightly higher than the world average. Meanwhile, 232Th activity ranges from 28.42 $$\pm$$ ± 1.12 to 69.43 $$\pm$$ ± 1.76 Bqkg−1 with the calculated mean value of 92.57 $$\pm$$ ± 1.17 Bqkg−1 while 40K activity ranged between 31.30 ± 1.32 and 328.65 ± 2.32 Bqkg−1 with the estimated mean 137.59 $$\pm$$ ± 2.42 Bqkg−1. Radiological parameters such as radium equivalent (Req), internal hazard (Hint) and external hazard (Hext) assessment were in the range of 66.00 Bqkg−1 to 141.76 Bqkg−1, 0.232 to 0.452 and 0.178 to 0.383, respectively. The measured values of gamma dose-rates ranged between 54.283 ± 0.78 and 117.531 ± 1.14 nGyh−1 with the calculated mean value of 84.770 ± 0.97 nGyh−1.

Cross-section measurements and production of 72Se with medium to high energy protons using arsenic containing targets

Experiments were performed to evaluate production of 72Se, parent radionuclide of the positron emitter 72As, at high energy at the Brookhaven Linac Isotope Producer (BLIP). Excitation functions for 75As(p, xn)72/75Se in the 52-105 MeV energy range were measured by irradiating thin gallium arsenide (GaAs) wafers. Maximum cross section value for the natAs(p, 4n)72Se reaction in the energy range was 103±9 mb at 52±1 MeV. Production size GaAs and arsenic metal (As°) targets were irradiated with 136 μA and 165 μA beam current possessing an initial Linac energy of 117 MeV. A total of 3.77±0.1 GBq (102±3 mCi) of 72Se was produced from a GaAs target at a calculated target entrance energy of 105.4 MeV, and 13.8±0.3 GBq (373±8 mCi) of 72Se from an As° target at a calculated incident energy of 49.5 MeV irradiated for 116.5 h and 68.9 h, respectively.

PEMBUATAN RADIONUKLIDA MOLIBDENUM-99 (99Mo) HASIL AKTIVASI NEUTRON DARI MOLIBDENUM ALAM UNTUK MEMPEROLEH TEKNESIUM-99m (99mTc)

PEMBUATAN RADIONUKLIDA MOLIBDENUM-99 (99Mo) HASIL AKTIVASI NEUTRON DARI MOLIBDENUM ALAM UNTUK MEMPEROLEH TEKNESIUM-99m (99mTc). Pembatasan penggunaan uranium sebagai target untuk produksi 99mTc menyebabkan rumah sakit di Indonesia kesulitan mendapatkan pasokan 99mTc. Saat ini 99mTc diperoleh dari 99Mo hasil fisi (pembelahan uranium). Pembuatan radionuklida 99Mo dari aktivasi neutron molibdenum alam (MoO3) di teras reaktor G.A Siwabessy digunakan sebagai metode alternatif untuk memperoleh 99mTc. Tujuan penelitian ini adalah untuk melakukan pembuatan radionuklida 99Mo dari aktivasi neutron molibdenum alam untuk memperoleh 99mTc. Serbuk MoO3 alam sebanyak 5 gram dikemas dalam ampul kuarsa dan dimasukkan ke dalam inner capsul selanjutnya dikemas menggunakan outer capsul sebagai bahan target. Bahan target diiradiasi di reaktor G.A Siwabessy selama 100 jam. Hasil perhitungan diperoleh aktivitas 99Mo sebesar 65 % dari nilai maksimum yang dapat diperoleh. MoO3 paska iradiasi dilarutkan dengan NaOH 4 M sehingga diperoleh larutan natrium molibdat (Na2MoO4). Radionuklida 99Mo dan 99mTc diukur menggunakan spektrometer gamma. Radionuklida 99Mo terdeteksi dalam produk larutan Na2MoO4 dengan aktivitas jenis 99Mo yang diperoleh sebesar 0,81 Ci 99Mo/g Mo. Radionuklida anak luruh 99mTc dipisahkan dari radionuklida induk 99Mo menggunakan kolom pemisah yang berisi material berbasis zirkonium (MBZ) sebagai penyerap 99Mo. Radionuklida 99mTc hasil pemisahan diperoleh dalam bentuk natrium pertehnetat (Na99mTcO4).dengan recovery yang masih rendah yaitu sekitar 52 hingga 71 %.Kata kunci: Molibdenum, teknesium, radionuklida, pemisahan, iradiasi. PRODUCTION OF ACTIVATED NEUTRON MOLYBDENUM-99 (99Mo) RADIONUCLIDE FROM NATURAL MOLYBDENUM TO OBTAIN TECHNETIUM-99m (99mTc). Uranium usage restriction causes the hospitals in indonesia difficult to obtain the suply of 99mTc. At Present, 99mTc is obtanied from molybdenum as a uranium fission product. Production of 99Mo radionuclide resulted from neutron activated natural molybdenum (MoO3) in G.A Siwabessy reactor could be used as a alternatif method for producing 99mTc. The aim of this research is synthesize of 99Mo radionuclide from neutron activated natural molybdenum (MoO3) to obtain 99mTc. The five grams of MoO3 powder was packed in a quartz ampule and inserted into inner capsule then also inserted into outer capsule as a target material. It was iradiated in G.A Siwabessy reactor for 100hours. Based on theoritical calculation, about 65 % of maximum 99Mo activity could be recovered. After Irradiation, MoO3 was dissolved by NaOH 4 M solution so it was natrium molybdate (Na2MoO4) solution. 99Mo and 99mTc radionuclide were analyzed using gamma spectrometer. 99Mo radionuclide was detected on Na2MoO4 solution as product that had specific activity of 0.81 Ci 99Mo/ g Mo. 99mTc as daughter radionuclide was separated from 99Mo as parent radionuclide using separated column containing zirconium based material (ZBM) as 99Mo adsobent. 99mTc radionuclide has been succesfully separated using ZBM column although recovery of 99mTc was quite low in which approximately 52 to 71 %. The 99mTc radionuclide was recovered in the form of sodium pertechnetate (NaTcO4) solution.Keywords: Molybdenum, technetium, radionuclide, separation, irradiation.