No abstract

Radiopharmaceuticals (RPC) used for diagnostic and therapeutic purposes in nuclear medicine may contaminate surface areas due to spillage during its preparation or accident during RPC transfer from laboratory to the treatment room. Fluorine-18 Fluorodeoxyglucose (18F-FDG) is the most common RPC for positron emission tomography (PET) scan in nuclear medicine due to its ideal annihilation converted energy at 511 keV and short half-life at 109.8 min. Ineffective medical waste management of 18F-FDG may pose a risk to the environment or cause unnecessary radiation doses to the personnel and public. Depending on the incident rate of these events, simple decontamination methods such as the use of chemicals and swabs might not be cost-effective and sustainable in the environment. This study aims to propose an alternative method to decontaminate 18F-FDG by using graphene oxide (GO). GO was synthesised using the Hummers method while the physical morphology was analysed using a field emission scanning electron microscope (FESEM). 18F-FDG adsorption efficiency rate using GO nanolayers was analysed based on the kinetic study of the GO:18F-FDG mixtures. The chemical adsorbability of the material was analysed via UV–vis spectrophotometer to interlink the microstructures of GO with the sorption affinity interaction. Resultantly, the adsorption rate was effective at a slow decay rate and the optical adsorption of GO with 18F-FDG was dominated by the π → π* plasmon peak, which was near 230 nm. By elucidating the underlining GO special features, an alternative technique to isolate 18F-FDG for the decontamination process was successfully proven.

Dealing with open sources of radioactive substances in nuclear medicine is a daily task since contamination due to radioactive spills may happen frequently. Proper and safe decontamination management is a vital procedure. However, regular purchase of decontamination agents incurs high costs and might be toxic due to their chemical properties. The purpose of this study is to compare graphene oxide, which is an environmentally friendly carbon-based material and marketable decontamination agent, in decontaminating radioactive spillage. Samples of pure 99mTc and 131I from the laboratory were spilled on a petri dish. The spill was immediately decontaminated with a marketable decontamination agent swab and varying concentrations of graphene oxide swab. The initial radioactivity of each swab containing 99mTc and 131I was measured using a dose calibrator. The absorbance spectra of each sample were analysed using an ultraviolet-visible spectrophotometer. The morphology image of graphene oxide was observed under field emission scanning electron microscope. For decontamination using a marketable decontamination agent, the radioactivity of 131I was slightly higher, whereas that of 99mTc was slightly lower than the high concentration of graphene oxide. The absorbance spectra of 99mTc and 131I that had been decontaminated using graphene oxide were observed at a range of 200 nm to 250 nm due ???* to the transition.