Management of the baseline shift using a new and simple method for respiratory‐gated radiation therapy: Detectability and effectiveness of a flexible monitoring system

Tachibana, Hideki; Kitamura, Nobuto; Ito, Yasushi; Kawai, Daisuke; Nakajima, Masaru; Tsuda, Akihisa; Shiizuka, Hisao

doi:10.1118/1.3598434

Cited by 14 publications

(6 citation statements)

References 44 publications

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“…For example, large marker recognition errors during low dose imaging can be reduced by image processing techniques [24,28]. The dynamic gating window technique [26] or management of the baseline shift [29] might also compensate for the variation of tumor motion and reduce toggling of the gate signals.…”

Section: Discussionmentioning

confidence: 99%

Optimization and evaluation of multiple gating beam delivery in a synchrotron-based proton beam scanning system using a real-time imaging technique

et al. 2016

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(Naoki Miyamoto) Purpose:To find the optimum parameter of a new beam control function installed in a synchrotron-based proton therapy system. Methods:A function enabling multiple gated irradiation in the flat top phase has been installed in a real-time-image gated proton beam therapy (RGPT) system. This function is realized by a waiting timer that monitors the elapsed time from the last gate-off signal in the flat top phase. The gated irradiation efficiency depends on the timer value, T w . To find the optimum T w value, gated irradiation efficiency was evaluated for each configurable T w value. 271 gate signal data sets from 58 patients were used for the simulation. Results:The highest mean efficiency 0.52 was obtained in T W = 0.2 s. The irradiation efficiency was approximately 21% higher than at T W = 0 s, which corresponds to ordinary synchrotron operation. The irradiation efficiency was improved in 154 (57%) of the 271 cases. The irradiation efficiency was reduced in 117 cases because the T W value was insufficient or the function introduced an unutilized wait time for the next gate-on signal in the flat top phase. In the actual treatment of a patient with a hepatic tumor at T w = 0.2 s, 4.48 GyE irradiation was completed within 250 s. In contrast, the treatment time of ordinary synchrotron operation was estimated to be 420 s. Conclusions:The results suggest that the multiple gated-irradiation function has potential to improve the gated irradiation efficiency and to reduce the treatment time.

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Section: Discussionmentioning

confidence: 99%

Optimization and evaluation of multiple gating beam delivery in a synchrotron-based proton beam scanning system using a real-time imaging technique

et al. 2016

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“…Hasta el momento, los programas comerciales no han implementado la capacidad de eliminar la componente respiratoria del movimiento en tiempo real, que siempre se podría estudiar a posteriori. 92,93 Una opción es aumentar el tiempo de promedio de cada adquisición de la superficie del paciente, para que integre el movimiento respiratorio, aunque eso aumente mucho el tiempo de respuesta del sistema a la hora de interrumpir el haz de radiación. Otros sistemas de SGRT disponen de la opción de adquirir imágenes de la superficie durante un intervalo de 10 a 20 segundos, permitiendo al usuario seleccionar como superficie de referencia aquella que se corresponda con la posición vertical representativa del movimiento respiratorio (la intermedia, para ITV que abarcan todo el ciclo).…”

Section: Tolerancias En La Monitorización Del Movimiento Intrafracciónunclassified

Informe del Grupo de Trabajo de la SEFM sobre Radioterapia Guiada por Superficie (SGRT): Procedimientos recomendados para la aceptación y puesta en funcionamiento

et al. 2022

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Se presentan las conclusiones del estudio realizado por el Grupo de Trabajo sobre Radioterapia Guiada por Superficie, promovido por la Sociedad Española de Física Médica. Los objetivos han sido la elaboración de procedimientos para la aceptación y puesta en funcionamiento de dispositivos de posicionamiento, monitorización y seguimiento, basados en el reconocimiento de la superficie del paciente, orientaciones para la adquisición e instalación de este equipamiento, así como establecer recomendaciones para un uso clínico fiable. Se ha delimitado el campo de estudio a los programas y dispositivos comerciales, evaluando las ventajas y limitaciones de estas técnicas para diferentes aplicaciones en Radioterapia. Basados en la bibliografía disponible, y en la experiencia de centros nacionales con implantación de la SGRT, se han establecido tolerancias y periodicidades para las distintas pruebas de control de calidad. Además, se han propuesto líneas de trabajo para la implantación de técnicas especiales que requieren mayor exactitud por parte de estos dispositivos. Finalmente, se han incluido tres anexos con orientaciones prácticas sobre la medida y análisis de las latencias de esos sistemas, la construcción de maniquíes de control de calidad para su medición, así como las implicaciones clínicas asociadas a las mismas en el tratamiento de lesiones sometidas a movimiento respiratorio.

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“…Among all kinds of motion, that due to respiration is the largest encountered in practice, and several approaches have been made to reduce its influence (9–16) . However, there are many other types of motion, some of them leading to significant problems.…”

Section: Introductionmentioning

confidence: 99%

“…Most of the patient positioning verification systems, like planar images or cone‐beam computed tomography (CBCT) with MV electronic portal imaging device (EPID) or kV on‐board imaging (OBI) system, use ionizing radiation to obtain an image of the patient; so they impart an additional dose of radiation to patients (26–28) . Other noninvasive methods track the external contour of the patient: optical infrared (IR) tracking of external markers, (16,23,25) optical surface image of patient, (22,29–33) time‐of‐flight sensors, (34) or tracking of external objects on the surface of the patient (12) . External tracking methods have the drawback of using surrogates of the actual organ motion, so it is necessary to verify the reproducibility between external and internal motion.…”

Section: Introductionmentioning

confidence: 99%

Development and clinical evaluation of a simple optical method to detect and measure patient external motion

Barbés

Azcona

Prieto

et al. 2015

J Applied Clin Med Phys

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A simple and independent system to detect and measure the position of a number of points in space was devised and implemented. Its application aimed to detect patient motion during radiotherapy treatments, alert of out‐of‐tolerances motion, and record the trajectories for subsequent studies. The system obtains the 3D position of points in space, through its projections in 2D images recorded by two cameras. It tracks black dots on a white sticker placed on the surface of the moving object. The system was tested with linear displacements of a phantom, circular trajectories of a rotating disk, oscillations of an in‐house phantom, and oscillations of a 4D phantom. It was also used to track 461 trajectories of points on the surface of patients during their radiotherapy treatments. Trajectories of several points were reproduced with accuracy better than 0.3 mm in the three spatial directions. The system was able to follow periodic motion with amplitudes lower than 0.5 mm, to follow trajectories of rotating points at speeds up to 11.5 cm/s, and to track accurately the motion of a respiratory phantom. The technique has been used to track the motion of patients during radiotherapy and to analyze that motion. The method is flexible. Its installation and calibration are simple and quick. It is easy to use and can be implemented at a very affordable price. Data collection does not involve any discomfort to the patient and does not delay the treatment, so the system can be used routinely in all treatments. It has an accuracy similar to that of other, more sophisticated, commercially available systems. It is suitable to implement a gating system or any other application requiring motion detection, such as 4D CT, MRI or PET.PACS numbers: 87.55.N, 87.56.Da

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Management of the baseline shift using a new and simple method for respiratory‐gated radiation therapy: Detectability and effectiveness of a flexible monitoring system

Cited by 14 publications

References 44 publications

Optimization and evaluation of multiple gating beam delivery in a synchrotron-based proton beam scanning system using a real-time imaging technique

Optimization and evaluation of multiple gating beam delivery in a synchrotron-based proton beam scanning system using a real-time imaging technique

Informe del Grupo de Trabajo de la SEFM sobre Radioterapia Guiada por Superficie (SGRT): Procedimientos recomendados para la aceptación y puesta en funcionamiento

Development and clinical evaluation of a simple optical method to detect and measure patient external motion

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