Initial Evaluation of a Novel Cone-Beam CT-Based Semi-Automated Online Adaptive Radiotherapy System for Head and Neck Cancer Treatment – A Timing and Automation Quality Study

Abstract

Introduction A novel on-line adaptive radiotherapy (ART) system based on O-ring linear accelerator (LINAC) and cone-beam CT (CBCT) was evaluated for treatment and management of head & neck (H&N) cancer in an emulated environment accessed via remote desktop connection. In this online ART system, organs-at-risk (OARs) and target contours and radiotherapy (RT) plans are semi-automatically generated based on the patient CBCT, expediting a typically hours-long RT planning session to under half an hour. In this paper, we describe our initial experiences with the system and explore optimization strategies to expedite the process further.

Clinical implementation of artificial intelligence-driven cone-beam computed tomography-guided online adaptive radiotherapy in the pelvic region

“…However, meticulous influencer definition minimizes the need to spend time on manual adjustments of propagated CTV. This corresponds well with observations in a recent study on a similar approach for head and neck cancer patients [28]. Editing propagated targets will break the Fig.…”

“…CBCT-based oART has been demonstrated feasible within reasonable session durations and with clinically acceptable deformation of structures to the anatomy of the day for a range of pelvic cases. Clinical oART sessions from acceptance of acquired CBCT to start of treatment delivery were achievable within a median of 17.6 min, which is competitive to other solutions [26,27] and also corresponds well with recent findings for simulated use of the present oART system for head and neck cancer patients [28]. With the novel CBCT-guided approach there is a potential to enable oART also for standard-fractionated treatments that so far has not been extensively investigated [12,29,30].…”

Initial analysis of the dosimetric benefit and clinical resource cost of CBCT‐based online adaptive radiotherapy for patients with cancers of the cervix or rectum

“…The most direct comparison of the measurements presented here can be made with the work of Yoon et al. who simulated adaptive treatments for head‐and‐neck cancer patients also using the Varian Ethos system 29 . Despite simulating the process for an entirely different treatment site, the average duration required to determine the influencer structure and target contours, and to generate an adaptive replan (11.8 and 6.1 min, respectively) were in agreement with those presented here for cervical cancer and rectal cancer patients.…”

“…To mitigate the time associated with the replanning effort, these systems use fast computer hardware and intelligent computer algorithms to accelerate the tasks, thereby facilitating their practical use for online ART. These include systems that adapt treatment plans based on daily‐acquired MRIs 21–27 and CBCTs 28,29 . Experience with both types of systems remains limited with their optimal implementation unknown.…”

Future mainstream platform for online adaptive radiotherapy will be using on‐board MR rather than on‐board (CB) CT images

“…One concern over CTgART is the low‐imaging quality for online delineation and the lack of soft‐tissue contrast for target visualization. Both FBCT and CBCT on the current ART platforms provide comparable image quality to the planning CT, which is already sufficient for many disease sites (head and neck, thorax, pelvis, spine, et al) 16,17 . Admittedly, MR images still provide higher tissue contrast, yet MRgART is probably only essential for sites that can benefit from ART and require superior soft‐tissue contrast, for example, abdominal regions.…”