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Background: Modern radiotherapeutic techniques, such as intensity‐modulated radiation therapy or stereotactic body radiotherapy, require high‐dose delivery precision. However, the precise localization of tumors during patient respiration remains a challenge. Therefore, it is essential to investigate effective methods for monitoring respiration to minimize potential complications. Despite several systems currently in clinical use, there are drawbacks, including the complexity of the setup, the discomfort to the patient, and the high cost. Purpose: This study investigated the feasibility of using a novel pressure sensor array (PSA) as a tool to monitor respiration during radiotherapy treatments. The PSA was positioned between the treatment couch and the back of the patient lying on it and was intended to overcome some limitations of current methods. The main objectives included assessing the PSA's capability in monitoring respiratory behavior and to investigate prospective applications that extend beyond respiratory monitoring. Methods: A PSA with 31 pressure‐sensing elements was used in 12 volunteers. The participants were instructed to breathe naturally while lying on a couch without any audio or visual guidance. The performance of the PSA was compared to that of a camera‐based respiratory monitoring system (RPM, Varian, USA), which served as a reference. Several metrics, including pressure distribution, weight sensitivity, and correlations between PSA and RPM signals, were analyzed. The PSA's capacity to provide information on potential applications related to patient stability was also investigated. Results: The linear relationship between the weight applied to the PSA and its output was demonstrated in this study, confirming its sensitivity to pressure changes. A comparison of PSA and RPM curves revealed a high correlation coefficient of 0.9391 on average, indicating consistent respiratory cycles. The PSA also effectively measured the weight distribution at the volunteer's back in real‐time, which allows for monitoring the patient's movements during the radiotherapy. Conclusion: PSA is a promising candidate for effective respiratory monitoring during radiotherapy treatments. Its performance is comparable to the established RPM system, and its additional capabilities suggest its multifaceted utility. This paper shows the potential use of PSA for patient monitoring in radiotherapy and suggests possibilities for further research, including performance comparisons with other existing systems and real‐patient applications with respiratory training. [ABSTRACT FROM AUTHOR]

Background/aim: This study aimed to compare the dosimetric consequences of respiratory movement in volumetric‐modulated arc therapy (VMAT) and three‐dimensional conformal radiation therapy (3D‐CRT) during postmastectomy radiation therapy, including internal mammary nodes (IMNs). Materials and methods: Respiratory motion was implemented to a phantom using a dynamic device. The plans were delivered during cranial‐caudal and ventral‐dorsal movement in 5‐mm (R05) and 10‐mm (R10) amplitudes. Results: At the IMN, the dose errors were –2.8% (R05) and –6.2% (R10) for 3D‐CRT and –4.9% (R05) and –8.5% (R10) for VMAT. The dose errors in chest wall were –.5% (R05) and –6.0% (R10) for 3D‐CRT and –1.9% (R05) and –5.3% (R10) for VMAT. The left anterior descending doses showed significantly small absolute values. The gamma pass rates of VMAT were higher than those of 3D‐CRT. Conclusions: The benefit of VMAT technique in dose distribution was maintained, except in occasional instances of large breathing motion. [ABSTRACT FROM AUTHOR]