Tehran University of Medical Sciences Basic & Clinical Cancer Research 2228-6527 13 4 2023 01 08 305 319 Reza Khoramdel Department of Physics, Shiraz Branch, Islamic Azad University, Shiraz, Iran Seyedehnasrin Hosseinimotlagh Department of Physics, Shiraz Branch, Islamic Azad University, Shiraz, Iran Zohreh Parang Department of Physics, Shiraz Branch, Islamic Azad University, Shiraz, Iran 2022 01 15 2022 08 13 The application of radiation therapy (RT) in lung cancer has shown some exciting and sometimes disappointing advances in recent years. Protons compared with photons interact differently with human tissues, and can be used to improve patient care for suffering from lung cancer. A new strategy is the simultaneous injection of nanoparticles with proton radiation into the tumor which has been given over a decade to improve conventional RT. In this work, proton beam therapy (PBT) with gold nanoparticles (GNPs) is used as a part of a combination program to treat advanced localized lung cancers. This paper aims to develop the complex Geant4 model on the human lung and predict the distribution of absorbed dose in lung tumors during proton therapy without and with a high-Z injection of GNPs. Thus, the absorbed dose distribution in lung tumors for four modes such as (i) Bethe-Bloch’s relativistic quantum theory, (ii) GEANT4/  GATE7 simulation model, (iii) Hartree-Fock-Roothaan(HFR) wave functions, and the(vi) Bortfeld theoretical model without and with the injection of GNPs in predicted lung phantom are compared. https://bccr.tums.ac.ir/index.php/bccrj/article/view/413