The clinical introduction of MR-guided radiation therapy from a RTT perspective

Botman, Russel; Tetar, S.; Palacios, Miguel; Slotman, Ben J.; Lagerwaard, Frank J.; Bruynzeel, A.

doi:10.1016/j.ctro.2019.04.019

Cited by 27 publications

(25 citation statements)

References 14 publications

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“…This is important because aside from the technical difficulties coming along with the integration of medical linear accelerators with MR scanners, the introduction of dedicated devices for MRgRT also implies new challenges for operating staff as well as patients. Patients at the MR-Linac are not only immobilized, but also need to tolerate placement of receiver coils while positioned in the bore for a longer time [22]. It is known that patients can experience claustrophobia and anxiety in an MR scanner [23,24], and the rate usually increases with longer and narrower bore openings [23,25].…”

Section: Discussionmentioning

confidence: 99%

First prospective clinical evaluation of feasibility and patient acceptance of magnetic resonance-guided radiotherapy in Germany

et al. 2020

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Purpose Magnetic resonance-guided radiotherapy (MRgRT) has recently been introduced in our institution. As MRgRT requires high patient compliance compared to conventional techniques and can be associated with prolonged treatment times, feasibility and patient tolerance were prospectively assessed using patient-reported outcome questionnaires (PRO-Q). Materials and methods Forty-three patients were enrolled in a prospective observational study and treated with MRgRT on a low-field hybrid Magnetic Resonance Linear Accelerator system (MR-Linac) between April 2018 and April 2019. For assistance in gated breath-hold delivery using cine-MRI, a video feedback system was installed. PRO-Qs consisted of questions on MR-related complaints and also assessed aspects of active patient participation. Results The most commonly treated anatomic sites were nodal metastases and liver lesions. The mean treatment time was 34 min with a mean beam-on time of 2:17 min. Gated stereotactic body radiotherapy (SBRT) was applied in 47% of all patients. Overall, patients scored MRgRT as positive or at least tolerable in the PRO-Q. Almost two thirds of patients (65%) complained about at least one item of the PRO-Q (score ≥4), mainly concerning coldness, paresthesia, and uncomfortable positioning. All patients reported high levels of satisfaction with their active role using the video feedback system in breath-hold delivery. Conclusion MRgRT was successfully implemented in our clinic and well tolerated by all patients, despite MR-related complaints and complaints about uncomfortable immobilization. Prospective clinical studies are in development for further evaluation of MRgRT and for quantification of the benefit of MR-guided on-table adaptive radiotherapy.

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Section: Discussionmentioning

confidence: 99%

First prospective clinical evaluation of feasibility and patient acceptance of magnetic resonance-guided radiotherapy in Germany

et al. 2020

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“…Under these circumstances, patients who have trouble tolerating treatment may have difficulty completing a fraction. 11 If an MRgRT system could move from step-and-shoot to sliding window, or even volumetric modulated arc therapy (VMAT) delivery, the results would be improved plan quality and decreased treatment time. For sliding window to be implemented, the MR image quality would have to be maintained during MLC motion.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of cine imaging during multileaf collimator and gantry motion for real‐time magnetic resonance guided radiation therapy

Kielbasa

Meeks

Kelly

et al. 2020

J Applied Clin Med Phys

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Real-time magnetic resonance guided radiation therapy (MRgRT) uses 2D cine imaging for target tracking. This work evaluates the percent image uniformity (PIU) and spatial integrity of cine images in the presence of multileaf collimator (MLC) and gantry motion in order to simulate sliding window and volumetric modulated arc therapy (VMAT) conditions. Methods: Percent image uniformity and spatial integrity of cine images were measured (1) during MLC motion, (2) as a function of static gantry position, and (3) during gantry rotation. PIU was calculated according to the ACR MRI Quality Control Manual. Spatial integrity was evaluated by measuring the geometric distortion of 16 measured marker positions (10 cm or 15.225 cm from isocenter). Results: The PIU of cine images did not vary by more than 1% from static linac conditions during MLC motion and did not vary by more than 3% during gantry rotation. Banding artifacts were present during gantry rotation. The geometric distortion in the cine images was less than 0.88 mm for all points measured throughout MLC motion. For all static gantry positions, the geometric distortion was less than 0.88 mm at 10 cm from isocenter and less than 1.4 mm at 15.225 cm from isocenter. During gantry rotation, the geometric distortion remained less than 0.92 mm at 10 cm from isocenter and less than 1.60 mm at 15.225 cm from isocenter. Conclusion: During MLC motion, cine images maintained adequate PIU, and the geometric distortion of points within 15.225 cm from isocenter was less than the 1 mm threshold necessary for real-time target tracking and gating. During gantry rotation, PIU was negatively affected by banding artifacts, and spatial integrity was only maintained within 10 cm from isocenter. Future work should investigate the effects imaging artifacts have on real-time target tracking during MRgRT.

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“…The possibility of prostate hypofractionation promises improved treatment and economic benefits ( 17 , 20 , 41 – 43 ). Users boost their hospital profile and professional development, irrespective of radiation oncologists, technologists and physicists ( 7 , 8 , 25 , 44 , 45 ). Our study also confirms the need to generate clinical evidence, while dealing with technical complexities and substantial staffing and structural investments ( 7 ).…”

Section: Discussion and Implications For Practice And Future Researchmentioning

confidence: 99%

Problems and Promises of Introducing the Magnetic Resonance Imaging Linear Accelerator Into Routine Care: The Case of Prostate Cancer

et al. 2020

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The new radiotherapy high field, 1.5 Tesla MRI-guided linear accelerator (MR-Linac) is being clinically introduced. Sensing and evaluating opportunities and barriers at an early stage will facilitate its eventual scale-up. This study investigates the opportunities and barriers to the implementation of MR-Linac into prostate cancer care based on 43 semi-structured interviews with Dutch oncology care professionals, hospital and division directors, patients, payers and industry. The analysis was guided by the Non-adoption, Abandonment, Scale-up, Spread, and Sustainability framework of new medical technologies and services. Opportunities included: the acquirement of ( 1 ) advanced MRI-guided radiotherapy technology with ( 2 ) the potential for improved patient outcomes and ( 3 ) economic benefits, as well as ( 4 ) professional development and ( 5 ) a higher hospital quality profile. Barriers included: ( 1 ) technical complexities, ( 2 ) substantial staffing and structural investments, ( 3 ) the current lack of empirical evidence of clinical benefits, ( 4 ) professional silos, and ( 5 ) the presence of patient referral patterns. While our study confirms the expected technical and clinical prospects from the literature, it also reveals economic, organizational, and socio-political challenges.

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The clinical introduction of MR-guided radiation therapy from a RTT perspective

Cited by 27 publications

References 14 publications

First prospective clinical evaluation of feasibility and patient acceptance of magnetic resonance-guided radiotherapy in Germany

First prospective clinical evaluation of feasibility and patient acceptance of magnetic resonance-guided radiotherapy in Germany

Evaluation of cine imaging during multileaf collimator and gantry motion for real‐time magnetic resonance guided radiation therapy

Problems and Promises of Introducing the Magnetic Resonance Imaging Linear Accelerator Into Routine Care: The Case of Prostate Cancer

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