Dosimetric feasibility of intensity modulated proton therapy in a transverse magnetic field of 1.5 T

Hartman, Joris; Kontaxis, Charis; Bol, Gijsbert H.; Frank, Steven J.; Lagendijk, J J W; Vulpen, Marco van; Raaymakers, B W

doi:10.1088/0031-9155/60/15/5955

Cited by 44 publications

(76 citation statements)

References 36 publications

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“…The application is being realized in a few clinics worldwide and first patients will be treated in the near future [Lagendijk et al, 2016]. Although the challenge of combining PT with MRI may be greater for particles than for photons, studies have shown the feasibility of a such combination [Hartman et al, 2015]. In addition, it was shown that particles could be used for imaging purposes as well, opening a wide field of new possibilities for PT [Prall et al, 2016a].…”

Section: Discussionmentioning

confidence: 99%

In silico comparison of photons versus carbon ions in single fraction therapy of lung cancer

et al. 2016

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Stereotactic body image guided radiation therapy (SBRT) shows excellent results for the local control of early stage lung cancer. However, not all patients are eligible for SBRT, and advanced stage treatment is less successful and often associated with severe side effects. Scanned carbon ion therapy (PT) can deliver more conformal dose likely benefiting these patient groups.Therefore an in silico trial was conducted on early and advanced stage patients to identify potential advantages of PT. The patients were treated with SBRT at Champalimaud Center for the Unknown, Lisbon (Portugal). PT plans were simulated on 4DCTs, and rescanning was investigated for motion mitigation in 4D-dose calculations. A dedicated strategy for 4D intensity modulated particle therapy (IMPT) was developed and applied for advanced stage patients with multiple lesions. For clinically valid and reliable results the deformable image registrationnecessary for 4D-dose calculation -a quality assurance tool was developed and applied in the study.The results showed that target coverage was comparable in SBRT and PT, while PT delivered significantly lower doses to most critical structures, especially the heart, lungs, and esophagus.A highly complex case of advanced stage lung cancer could be treated in a single fraction of 24 Gy with PT, while SBRT could not deliver the full ablative dose treatment due to an excessive heart dose. The mean heart dose was reduced from 10 Gy to 0.8 Gy with PT for this specific patient.

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Section: Discussionmentioning

confidence: 99%

In silico comparison of photons versus carbon ions in single fraction therapy of lung cancer

et al. 2016

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“…These include estimation of the deflection inside a water phantom by Raaymakers et al 18 and Wolf and Bortfeld. 19 Optimized patient-based planning in uniform magnetic fields to account for the imaging field deflection has also been studied by Moteabbed et al 20 and Hartman et al 21 These studies assumed a static external magnetic field without fringe field effects as being the influence of the MRI scanner. It has been shown recently, however, that the fringe field of an MRI scanner has a complex and significant impact on how a proton beam transports towards the MRI isocenter.…”

Section: C Existing Literature In Mrptmentioning

confidence: 99%

“…The latter component of this approach has been performed already in previous works where the extent of the uniform imaging field is 70 cm in diameter. 21 The true advantage of separating the dose planning into the two components mentioned above is that, once part (a) is completed for a unique MRPT design, then the LUT of data describing the fringe field deflection and pencil beam scanning process can be passed onto independent dose planning engines. The only requirement is that plans must be optimized according to the planning volume boundary specified in the LUT.…”

Section: B Dose Planning In Magnetic Fieldsmentioning

confidence: 99%

Future of medical physics: Real‐time MRI‐guided proton therapy

et al. 2017

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With the recent clinical implementation of real-time MRI-guided x-ray beam therapy (MRXT), attention is turning to the concept of combining real-time MRI guidance with proton beam therapy; MRIguided proton beam therapy (MRPT). MRI guidance for proton beam therapy is expected to offer a compelling improvement to the current treatment workflow which is warranted arguably more than for x-ray beam therapy. This argument is born out of the fact that proton therapy toxicity outcomes are similar to that of the most advanced IMRT treatments, despite being a fundamentally superior particle for cancer treatment. In this Future of Medical Physics article, we describe the various software and hardware aspects of potential MRPT systems and the corresponding treatment workflow. Significant software developments, particularly focused around adaptive MRI-based planning will be required. The magnetic interaction between the MRI and the proton beamline components will be a key area of focus. For example, the modeling and potential redesign of a magnetically compatible gantry to allow for beam delivery from multiple angles towards a patient located within the bore of an MRI scanner. Further to this, the accuracy of pencil beam scanning and beam monitoring in the presence of an MRI fringe field will require modeling, testing, and potential further development to ensure that the highly targeted radiotherapy is maintained. Looking forward we envisage a clear and accelerated path for hardware development, leveraging from lessons learnt from MRXT development. Within few years, simple prototype systems will likely exist, and in a decade, we could envisage coupled systems with integrated gantries. Such milestones will be key in the development of a more efficient, more accurate, and more successful form of proton beam therapy for many common cancer sites.

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“…Collaborative utilization of CST and GEANT4 might be a possible way to accurately predict magnetic‐induced deflections and provide useful information for deflection rectifications. Proton deflection rectifications under high magnetic fields have been described in a beneficial study on magnetic resonance imaging‐guided proton therapy . Above descriptions provide possible strategies and solutions for accomplishing magnetic field shielding tasks of MMPT.…”

Section: Discussionmentioning

confidence: 99%

Modulation of lateral positions of Bragg peaks via magnetic fields inside cancer patients: Toward magnetic field modulated proton therapy

et al. 2017

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The BP positions can be intentionally modulated to produce uniform tumor doses under the magnetic fields inside cancer patients. In some special cases, the vital organs surrounding the tumor can almost be exempted from proton irradiations without sacrificing tumor dose coverage through MMPT. For the tumors inside parallel organs, the parallel organ volume receiving proton irradiations was largely reduced through MMPT. The results of this study can serve as beneficial implications for future proton therapy studies with reduced vital organ damage and complications.

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Dosimetric feasibility of intensity modulated proton therapy in a transverse magnetic field of 1.5 T

Cited by 44 publications

References 36 publications

In silico comparison of photons versus carbon ions in single fraction therapy of lung cancer

In silico comparison of photons versus carbon ions in single fraction therapy of lung cancer

Future of medical physics: Real‐time MRI‐guided proton therapy

Modulation of lateral positions of Bragg peaks via magnetic fields inside cancer patients: Toward magnetic field modulated proton therapy

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