Investigation of 18F and 89Zr Isotopes Self-Absorption and Dose Rate Parameters for PET Imaging

This work concerns study of self-absorption factor (SAF) and dose rate constants of zirconium-89 (89Zr) for the purpose of radiation protection in positron emission tomography (PET) and to compare them with those of 18F-deoxyglucose (18F-FDG). We analyzed the emitted energy spectra by 18F and 89Zr through anthropomorphic phantom and calculated the absorbed energy using Monte Carlo method. The dose rate constants for both radionuclides were estimated with 2 different fluence-to-effective dose conversion coefficients. Our estimated SAF value of 0.65 for 18F agreed with the recommendation of the American Association of Physicists in Medicine (AAPM). The SAF for 89Zr was in the range of 0.61-0.66 depending on the biodistribution. Using the fluence-to-effective dose conversion coefficients recommended jointly by the American National Standards Institute and the American Nuclear Society (ANSI/ANS), the dose rate at 1 m from the patient for 18F was 0.143 μSv·MBq−1·hr−1, which is consistent with the AAPM recommendation, while that for 89Zr was 0.154 μSv·MBq−1·hr−1. With the conversion coefficients currently recommended by the International Committee on Radiological Protection (ICRP), the dose rate estimates were lowered by 2.8% and 2.6% for 89Zr and 18F, respectively. Also, we observed that the AAPM derived dose is an overestimation near the patient, compared to our simulations, which can be explained by the biodistribution nature and the assumption of the point source. Thus, we proposed new radiation protection factors for 89Zr radionuclide.

Environmental effects and initiatives of nuclear power via international initiatives in 1980s as a bipolar international policy

In 1980 American Nuclear Society scholars Walter Jordan and Samuel Glasstone delivered a coherent and methodological presentation of the consequences of nuclear power on the environment. Focusing on a multitude of matters extending from nuclear power and reactor safety to the discarding of waste heat and the biological outcomes of radiation, enclosed many of the concerns involving to nuclear environmental effect. Furthermore, America’s diverse legacy has allowed competing claimants to propose conflicting opinions of its position in the conclusion of the Cold War and the reduction of nuclear conflicts in the 1990s. Particular specifics, nevertheless, are beyond argument. United States headed over a immense nuclear accumulation and sprung an costly struggle to construct a defense versus strategic missiles that aggravated frictions with Soviet Union. This paper is aimed for specialists in any specific area and they will find the study presented as of a specific time period in nature and is therefore studies of later periods is recommended for advanced studies. Nevertheless, the educated scholars will possibly find the study informative and illuminating, and the paper will serve well the commitment to educating of misinformed community too. This study is thus endorsed for use in any activities engaged at public education in its subject matter.