Abstract: This study analyzes the recent advancements in radiation therapy equipment technology, focusing on medical linear accelerators, conformal intensity-modulated radiation therapy technology, proton and heavy ion therapy equipment, as well as new mobile radiation therapy devices and high-dose-rate therapy modes. The study highlights the challenges in aligning the development of radiation therapy technologies with existing radiation protection standards. The analysis result indicates that the growth and application of certain new technologies are constrained by current radiation protection standards. Specifically, the use of the instantaneous maximum ambient dose equivalent rate as a criterion for evaluating radiation therapy rooms is inconsistent with real working conditions, making it difficult to control personnel exposure based on variations in dwell time and workload. This can lead to a significant increase in construction costs for shielding design. Furthermore, the current standards do not adequately account for changes in beam angles associated with new technologies, and the conditions for maximum field size and dose rate measurement do not accurately align with clinical practices. Based on this analysis, it is recommended that the current radiation protection standards for radiation therapy should be revised to replace the traditional evaluation criterion with the time-averaged maximum ambient dose equivalent rate. Additionally, relevant parameters and conditions should be optimized to better accommodate the evolving needs of modern radiation therapy equipment. By updating and refining existing radiation protection standards, the safety of radiation therapy can be better ensured while fostering the adoption of new radiation therapy technologies, ultimately achieving a harmonious development of radiation protection standards and radiation therapy equipment technology.

Key words: radiotherapy, radiation protection, standards, instantaneous dose rate