ABSTRACT
The use of radio frequency for medical application is increasing rapidly, especially for nanomedicine, which shows the most imperative role of human daily life in diagnostic and therapeutic aspects. Generally, radio frequency for therapeutic use known as radiotherapy involves the use of high-energy radiation from X-rays, γ-rays, neutrons, electrons, protons, and other sources to kill cancer cells and shrink tumors. There are two main types of radiotherapy: external-beam radiation therapy and internal radiation therapy (brachytherapy). The external-beam radiation therapy (EBRT) directs radiation beams at the tumor from outside the patient’s body and normally the radiation beam is generated by a linear accelerator whereas the internal beam radiation therapy is the therapy in which a single or multiple radioactive sources are placed inside the patient’s body [1]. An antenna is an essential component for signal radiation, which changes radiation intensity, or to exploit the transmitted power [2]. The surface plasmon resonance [3,4] characteristics describe the optical frequencies and exploit them to balance the drawbacks of antenna systems in the very-high-frequency spectrum range. Gold nanoparticles are extensively used as a nano-antenna due to perfect conduction and controllable size distribution, longterm stability, high homogeneity, and they also contribute plasmon resonances in the visible spectrum [5,6,7]. There are various types of nano-antennas available for therapeutic use, for instance, nanospheres and nanorods [5,8], bowtie nano-antennas [9], Yagi-Uda nano-antennas [10], and dipole nano-antennas [11].
