Hong & Zhang’s “Simulation analysis for tumor radiotherapy based on three-component mathematical models” in the recent issue of JACMP addressed an important topic that deserves much attention, because mathematical predictions of treatment response may ultimately help personalize radiation dose and fractionation. Hong & Zhang conclude from model simulation that a three-compartment model impacts radiotherapy efficacy and outcome of simulated radiotherapy was affected by the proportion of quiescent tumor cells, radiation dose per fraction, and radiosensitivity. Although intuitive and well-supported by literature, we found selected discrepancies and inaccuracies with regards to these specific claims, in addition to several discrepancies in the mathematical formulation of their model, which we describe here in a Letter to the Editor.