The Linear No Threshold Model (LNT) defines that cancer occurrence due to radiation exposure exhibits linearity without a threshold. Many research results have confirmed the clear linearity of radiation exposure and cancer risk at high doses. However, controversy exists at low doses (<100 mSv) and low dose rates (<0.1 mSv/min, <5 mSv/hour) intervals. Within the low dose range of 100 mSv or less, the LNT model assumes a linear relationship between radiation exposure and cancer risk, with no threshold dose for cancer occurrence. It suggests that even low doses of radiation carry a probability of cancer occurrence, proportional to the dose of radiation, with no threshold value. Workers in nuclear medicine work in environments where they are exposed to radiation on a daily basis. Especially with over 30 years of work, the likelihood of exposure to doses below 100 mSv is very high. Therefore, a thorough understanding of the LNT model is essential. Based on this, continuous efforts are necessary to find radiation protection methods for low doses. To this end, the author aims to assist workers in nuclear medicine by seeking out the latest data, papers, and research from international radiation-related committees, epidemiology, physics, and radiation protection studies to facilitate a precise understanding of the current LNT model.