Magnetic resonance imaging (MRI) guided proton therapy: A review of the clinical challenges, potential benefits and pathway to implementation

Pham, Toan M.; Whelan, Brendan; Oborn, Bradley M; Delaney, Geoff P.; Vinod, Shalini; Brighi, Caterina; Bartoň, Michael; Keall, P.

doi:10.1016/j.radonc.2022.02.031

Cited by 18 publications

(15 citation statements)

References 108 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Perhaps as technical challenges are overcome, the coalescence of PBT and MRgRT may potentially be on the horizon. 98,[113][114][115][116] Further Directions of MRgRT for HCC Development of auto-contouring programs is a current area of interest as manual contouring can be laborious and timeconsuming for clinicians. Improved soft tissue delineation with MRI, compared to CT, may improve anatomic segmentation.…”

Section: Limitations Of Mrgrt For Hccmentioning

confidence: 99%

Proton Beam Therapy and Photon-Based Magnetic Resonance Image-Guided Radiation Therapy: The Next Frontiers of Radiation Therapy for Hepatocellular Carcinoma

Zaki,

Chuong,

Schaub

et al. 2023

Technol Cancer Res Treat

View full text Add to dashboard Cite

External beam radiation therapy (EBRT) has increasingly been utilized in the treatment of hepatocellular carcinoma (HCC) due to technological advances with positive clinical outcomes. Innovations in EBRT include improved image guidance, motion management, treatment planning, and highly conformal techniques such as intensity-modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT). Moreover, proton beam therapy (PBT) and magnetic resonance image-guided radiation therapy (MRgRT) have expanded the capabilities of EBRT. PBT offers the advantage of minimizing low- and moderate-dose radiation to the surrounding normal tissue, thereby preserving uninvolved liver and allowing for dose escalation. MRgRT provides the advantage of improved soft tissue delineation compared to computerized tomography (CT) guidance. Additionally, MRgRT with online adaptive therapy is particularly useful for addressing motion not otherwise managed and reducing high-dose radiation to the normal tissue such as the stomach and bowel. PBT and online adaptive MRgRT are emerging technological advancements in EBRT that may provide a significant clinical benefit for patients with HCC.

show abstract

Section: Limitations Of Mrgrt For Hccmentioning

confidence: 99%

Proton Beam Therapy and Photon-Based Magnetic Resonance Image-Guided Radiation Therapy: The Next Frontiers of Radiation Therapy for Hepatocellular Carcinoma

Zaki,

Chuong,

Schaub

et al. 2023

Technol Cancer Res Treat

View full text Add to dashboard Cite

show abstract

“…11,[30][31][32] Also CBCT scanners are becoming more widespread in proton therapy facilities, 11 and several methods to correct the acquired CBCT images for artifacts and rescale the image intensities to allow accurate dose calculations have been proposed in the literature. [33][34][35] MR-guided proton therapy is a promising future treatment modality, [36][37][38][39] and first prototype systems have been constructed. 40 Several technological and methodological advancements that are additionally required for the clinical implementation of online adaptive proton therapy have been achieved in the last decade.…”

Section: Introductionmentioning

confidence: 99%

Comparison of MR‐guided radiotherapy accumulated doses for central lung tumors with non‐adaptive and online adaptive proton therapy

et al. 2023

View full text Add to dashboard Cite

Background: Stereotactic body radiation therapy (SBRT) of central lung tumors with photon or proton therapy has a risk of increased toxicity. Treatment planning studies comparing accumulated doses for state-of -the-art treatment techniques, such as MR-guided radiotherapy (MRgRT) and intensity modulated proton therapy (IMPT), are currently lacking. Purpose: We conducted a comparison of accumulated doses for MRgRT, robustly optimized non-adaptive IMPT, and online adaptive IMPT for central lung tumors. A special focus was set on analyzing the accumulated doses to the bronchial tree, a parameter linked to high-grade toxicities. Methods: Data of 18 early-stage central lung tumor patients, treated at a 0.35 T MR-linac in eight or five fractions, were analyzed. Three gated treatment scenarios were compared: (S1) online adaptive MRgRT, (S2) non-adaptive IMPT, and (S3) online adaptive IMPT. The treatment plans were recalculated or reoptimized on the daily imaging data acquired during MRgRT, and accumulated over all treatment fractions. Accumulated dose-volume histogram (DVH) parameters of the gross tumor volume (GTV), lung, heart, and organs-at-risk (OARs) within 2 cm of the planning target volume (PTV) were extracted for each scenario and compared in Wilcoxon signed-rank tests between S1 & S2, and S1 & S3. Results: The accumulated GTV D 98% was above the prescribed dose for all patients and scenarios. Significant reductions (p < 0.05) of the mean ipsilateral lung dose (S2: -8%; S3: -23%) and mean heart dose (S2: -79%; S3: -83%) were observed for both proton scenarios compared to S1. The bronchial tree D 0.1cc was significantly lower for S3 (S1: 48.1 Gy; S3: 39.2 Gy; p = 0.005), but not significantly different for S2 (S2: 45.0 Gy; p = 0.094), compared to S1. The D 0.1cc for S2 and S3 compared to S1 was significantly (p < 0.05) smaller for OARs within 1-2 cm of the PTV (S1: 30.2 Gy; S2: 24.6 Gy; S3: 23.1 Gy), but not significantly different for OARs within 1 cm of the PTV. Conclusions: A significant dose sparing potential of non-adaptive and online adaptive proton therapy compared to MRgRT for OARs in close, but not direct proximity of central lung tumors was identified. The near-maximum dose to the bronchial tree was not significantly different for MRgRT and non-adaptive IMPT.

show abstract

“…Integrating MRI into the treatment process enables real-time visualization of the tumour and surrounding anatomy, allowing for more precise dose delivery. While for MR-guided photon therapy, two commercial systems are in clinical use (Mutic andDempsey 2014, Raaymakers et al 2017), MR-guided proton therapy is just beginning to be investigated (Oborn et al 2017, Pham et al 2022 with proof of concept and first experimental results having been recently reported using experimental systems (Schellhammer et al 2018a, 2018b, Lühr et al 2019, Padilla-Cabal et al 2019, Gantz et al 2020, Fuchs et al 2022.…”

Section: Introductionmentioning

confidence: 99%

A fast analytical dose calculation approach for MRI-guided proton therapy

Duetschler,

Winterhalter,

Meier

et al. 2023

Phys. Med. Biol.

View full text Add to dashboard Cite

Objective. Magnetic resonance (MR) is an innovative technology for online image guidance in conventional radiotherapy and is also starting to be considered for proton therapy as well. For MR-guided therapy, particularly for online plan adaptations, fast dose calculation is essential. Monte Carlo (MC) simulations, however, which are considered the gold standard for proton dose calculations, are very time-consuming. To address the need for an efficient dose calculation approach for MRI-guided proton therapy, we have developed a fast GPU-based modification of an analytical dose calculation algorithm incorporating beam deflections caused by magnetic fields. Approach. Proton beams (70–229 MeV) in orthogonal magnetic fields (0.5/1.5 T) were simulated using TOPAS-MC and central beam trajectories were extracted to generate look-up tables (LUTs) of incremental rotation angles as a function of water-equivalent depth. Beam trajectories are then reconstructed using these LUTs for the modified ray casting dose calculation. The algorithm was validated against MC in water, different materials and for four example patient cases, whereby it has also been fully incorporated into a treatment plan optimisation regime. Main results. Excellent agreement between analytical and MC dose distributions could be observed with sub-millimetre range deviations and differences in lateral shifts <2 mm even for high densities (1000 HU). 2%/2 mm gamma pass rates were comparable to the 0 T scenario and above 94.5% apart for the lung case. Further, comparable treatment plan quality could be achieved regardless of magnetic field strength. Significance. A new method for accurate and fast proton dose calculation in magnetic fields has been developed and successfully implemented for treatment plan optimisation.

show abstract

Magnetic resonance imaging (MRI) guided proton therapy: A review of the clinical challenges, potential benefits and pathway to implementation

Cited by 18 publications

References 108 publications

Proton Beam Therapy and Photon-Based Magnetic Resonance Image-Guided Radiation Therapy: The Next Frontiers of Radiation Therapy for Hepatocellular Carcinoma

Proton Beam Therapy and Photon-Based Magnetic Resonance Image-Guided Radiation Therapy: The Next Frontiers of Radiation Therapy for Hepatocellular Carcinoma

Comparison of MR‐guided radiotherapy accumulated doses for central lung tumors with non‐adaptive and online adaptive proton therapy

A fast analytical dose calculation approach for MRI-guided proton therapy

Contact Info

Product

Resources

About