Abstract
We developed a synchrotron‐based real‐time‐image gated‐spot‐scanning proton‐beam therapy (RGPT) system and utilized it to clinically operate on moving tumors in the liver, pancreas, lung, and prostate. When the spot‐scanning technique is linked to gating, the beam delivery time with gating can increase, compared to that without gating. We aim to clarify whether the total treatment process can be performed within approximately 30 min (the general time per session in several proton therapy facilities), even for gated‐spot‐scanning proton‐beam delivery with implanted fiducial markers. Data from 152 patients, corresponding to 201 treatment plans and 3577 sessions executed from October 2016 to June 2018, were included in this study. To estimate the treatment process time, we utilized data from proton beam delivery logs during the treatment for each patient. We retrieved data, such as the disease site, total target volume, field size at the isocenter, and the number of layers and spots for each field, from the treatment plans. We quantitatively analyzed the treatment process, which includes the patient load (or setup), bone matching, marker matching, beam delivery, patient unload, and equipment setup, using the data obtained from the log data. Among all the cases, 90 patients used the RGPT system (liver: n = 34; pancreas: n = 5; lung: n = 4; and prostate: n = 47). The mean and standard deviation (SD) of the total treatment process time for the RGPT system was 30.3 ± 7.4 min, while it was 25.9 ± 7.5 min for those without gating treatment, excluding craniospinal irradiation (CSI; head and neck: n = 16, pediatric: n = 31, others: n = 15); for CSI (n = 11) with two or three isocenters, the process time was 59.9 ± 13.9 min. Our results demonstrate that spot‐scanning proton therapy with a gating function can be achieved in approximately 30‐min time slots.
Highlights
The number of proton‐beam therapy facilities is rapidly increasing worldwide.[1]
We developed and clinically operated a real‐time‐image gated‐spot‐scanning proton‐beam therapy (RGPT) system without using the respiration waveform inherited from the basic properties of the x ray real‐ time tumor‐tracking radiation therapy (RTRT) system developed by Shirato et al.[4,9–11]
We evaluated the treatment process time, which included the duration of each process from when the patient walked into the treatment room to when they walked out
Summary
The number of proton‐beam therapy facilities is rapidly increasing worldwide.[1]. Among the several treatment delivery systems in proton‐beam therapy, spot‐scanning proton therapy (SSPT) is one of the more promising technologies. In spot‐scanning methods, the prescribed dose for each field is delivered by thousands or tens of thousands of pencil beams, spot‐by‐spot and layer‐by‐layer, from the nozzle to the target.[2]. This method has a higher beam utilization than conventional methods such as the double scatter method. It does not require boluses or collimators and enables intensity‐modulated proton therapy (IMPT).[3]. This scanning method has become the mainstay in many new facilities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
