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OncoRay Launches World's First Whole-body MRI-guided Proton Therapy System

Launch ceremony Research leader Aswin Hoffmann (right) presents the MRI-guided proton therapy prototype to Michael Kretschmer, the Minister-President of the Free State of Saxony (centre) and Sebastian Gemkow, the Saxon State Minister for Science (left). (Courtesy: UKD/Michael Kretzschmar)

This week saw the official inauguration of the world's first research prototype for whole-body MRI-guided proton therapy. The launch ceremony, at OncoRay – the National Center for Radiation Research in Oncology in Dresden, marked the start of scientific operation using the prototype, which is designed to enable real-time MRI tracking of moving tumours during proton therapy.

Proton therapy provides a means to treat tumours with extreme precision. The finite range of a proton beam enables extremely conformal dose targeting with reduced dose to nearby healthy tissue. This high conformality, however, makes proton treatments particularly sensitive to anatomical changes in the beam path, which can impair the targeting precision when treating a moving target. Real-time imaging during treatment could help solve this drawback by synchronizing dose delivery with the tumour position.

MRI provides a way to visualize moving tumours and surrounding healthy tissue with excellent soft-tissue contrast. Performing MRI during treatment delivery could enable real-time visualization of tumour motion and the potential for real-time adaptation. MRI can also detect any anatomical changes between consecutive treatment sessions.

And while MRI guidance for photon-based radiotherapy is now commercially available and in clinical use, OncoRay's is the first such system that exploits MRI to guide proton therapy.

The prototype device – developed by OncoRay's Experimental MR-Integrated Proton Therapy research group, led by Aswin Hoffmann – combines a horizontal proton therapy beamline with a whole-body MRI scanner that rotates around the patient. Hoffmann notes that this geometry enables innovative patient positioning approaches, including treatment in both lying or in upright positions.

Treatment guidance The proton therapy beamline (left) and the opened MRI-guided proton therapy prototype showing the in-beam MRI (centre) and patient couch (right). The prototype was developed in cooperation with industry partners: ASG Superconductors in Italy manufactured the MRI device, while MagnetTx Oncology Solutions in Canada designed the rotating gantry and developed the tumour tracking software. (Courtesy: UKD/Kirsten Lassig)

The ultimate goal of the OncoRay team, along with scientists from the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) and the Dresden University Medical Center, is to use real-time MRI to monitor cancer patients during their treatments and significantly improve the targeting accuracy of proton therapy.

Hoffmann tells Physics World that the first study using the new prototype MRI–proton therapy system is designed to assess the mutual electromagnetic interactions between the proton pencil-beam scanning (PBS) beamline and the in-beam MRI scanner. "We need to answer two questions," he explains, "do the magnetic fringe fields produced by the PBS beamline affect the MR image quality during irradiation and does the static magnetic field of the MRI system affect the beam delivery system?"

One step closer to real-time MR imaging in proton therapy In the longer term, the researchers will use the prototype to demonstrate the added value that whole-body, real-time MRI guidance could bring to treatments of mobile tumours in the chest, abdomen and pelvis. "I have been working on this specific project since 2018, the last three years of which [I worked] very intensively with the industry partners involved. I am proud that together we have managed to realize and put this system into operation. I look forward with great anticipation to the next phase in which the scientific challenges will be addressed," says Hoffmann.

Proton Therapy On The Rise In U.S.

Photo Credit: Dr. Microbe

The National Association for Proton Therapy's surveys from 2012 to 2021 show a rise in proton therapy recipients, a decline in prostate cancer cases, and notable increases in pediatric, CNS, and skull base treatments, indicating evolving patient trends and treatment complexity.

The following is a summary of "Temporal Evolution and Diagnostic Diversification of Patients Receiving Proton Therapy in the United States: A Ten-Year Trend Analysis (2012-21) from the National Association for Proton Therapy," published in the December 2023 issue of Oncology by Hartsell et al.

From 2012 to 2021, the the National Association for Proton Therapy conducted a comprehensive assessment through eight surveys encompassing operational proton centers across the United States. This analysis aimed to evaluate the evolving trends and diversification in patients undergoing proton therapy by scrutinizing treated cases, diagnoses, and treatment complexity.

Beginning in 2015 and subsequently annually, detailed surveys were dispatched to active proton centers in the US, soliciting data from 2012 to 2014 and for the preceding calendar year(s). Collated patient numbers treated at each center were categorized based on tumors in various segments: central nervous system (CNS), intraocular, pituitary, skull base/skeleton, head/neck, lung, retroperitoneal/soft tissue sarcoma, pediatric (solid tumors in children aged ≤18), gastrointestinal tract, urinary tract, female pelvic, prostate, breast, and categorized as "other." Complexity assessments relied on CPT codes 77520-77525.

Noteworthy survey response rates were observed, ranging from 100% in 2015 to 94.9% in 2021, with supplementary publicly available data yielding nearly comprehensive information on all centers. Comparative trend analysis between 2012 and 2021 revealed a gradual increase in the annual total number of patients receiving proton therapy, escalating from 5,377 to 15,829. Considerable numeric upticks were evident in head/neck (316 to 2,303; 7.3-fold), breast (93 to 1,452; 15.6-fold), and gastrointestinal cases (170 to 1,259; 7.4-fold). Likewise, notable increments were observed for the central nervous system (598 to 1,743; 2.9-fold), pediatric (685 to 1,870; 2.7-fold), and skull base (179 to 514; 2.9-fold) treatments. Conversely, the percentage of proton-treated patients for prostate cancer decreased from 43.4% to 25.0% of the total. Simple compensated treatments decreased from 43% in 2012 to 7% in 2021, while intermediate complexity treatments surged from 45% to 73%.

This analysis delineates a gradual surge in proton therapy recipients, indicating a marked proportional decline among patients receiving proton treatment for prostate cancer. Notably, treatments for pediatric, CNS, and skull base cases, considered typical indications for proton therapy, exhibited a gradual increase. Moreover, substantial proportional escalations were witnessed for breast, lung, head/neck, and gastrointestinal tumors, signifying evolving trends in patient demographics. An upward trajectory in treatment complexity over time was also observed.

Source: sciencedirect.Com/science/article/abs/pii/S0360301623083153

Dresden Makes Waves In Cancer Treatment With Pioneering MRI-guided Proton Therapy

Jan 9 2024

On January 9th, 2024, a scientific prototype for MRI-guided proton therapy was inaugurated in Dresden. With this installation, experts from the fields of medicine, medical physics, biology and engineering are embarking on the scientific testing of a new form of radiotherapy for treating cancer. For the first time globally, a full-body MRI device for real-time imaging is combined with a proton therapy system in the form of a prototype. The inauguration ceremony was held at OncoRay - National Center for Radiation Research in Oncology with Saxony's Minister-President Michael Kretschmer present. After demonstrating the technical feasibility using a compact MRI device without real-time imaging with a predecessor prototype financed by the Sächsische Aufbaubank in 2019, the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) has now financed the development of a pioneering full-body MRI device with real-time imaging. The infrastructure as well as a number of the personnel are provided by the Dresden University Medical Center.

The aim of the Saxon physicians together with scientists from the HZDR and the Dresden University Medical Center is to monitor cancer patients during their radiation treatment using real-time MRI imaging and thus to significantly improve the targeting accuracy of proton therapy. A globally unique combination of a full-body MRI machine that rotates around the patient for real-time imaging and a proton therapy system was created in Dresden. Scientific operation has now begun in January 2024.

The MRI's advantage over conventional imaging modalities is that it can visualize the tumor in higher contrast. This makes it possible to better delineate the tumor from surrounding healthy tissue and to define the volume to be irradiated more accurately. Furthermore, MRI imaging can visualize any potential changes in the shape and size of the volume to be irradiated between consecutive radiation sessions. This enables the beam application to be adjusted individually and immediately. In addition, it allows the real-time MRI imaging to visualize tumor movement during a radiation session and to synchronize it with the radiation application. The prototype that has now been installed will be the first of its kind globally to investigate the extent to which the accuracy of proton therapy can be improved with the help of full-body real-time MRI imaging.

At the OncoRay - National Center for Radiation Research in Oncology, the "Experimental MR-Integrated Proton Therapy" research group led by Prof. Aswin Hoffman has developed the new system. This was a technological challenge, as both the MRI device and the proton radiation system work with magnetic fields, which interact with one another and thus influence the quality of the imaging as well as the proton beam application. Having already demonstrated the technical feasibility of simultaneous radiation and imaging using a prior prototype, the research group can now utilize the new system for the first time worldwide to examine the extent to which it is possible to do so using real-time MRI imaging. "This new prototype with integrated full-body MRI makes it possible to visualize moving tumors using high-contrast real-time imaging. Our work aims to develop a technique to irradiate tumors only when they are hit reliably by the proton beam," says Hoffmann. "The MRI device, which can rotate around the patient, enables us to use innovative types of patient positioning for proton therapy in both lying or in upright positions." The prototype will be used in future studies to demonstrate the added value of this new prototype for mobile tumors in the chest, abdomen and pelvis.

The prototype has been erected in the proton therapy facility's experimental room at OncoRay on the premises of the School of Medicine Dresden. There, an international team of researchers is working on innovative ways of treating cancer. Thanks to a large experimental room adjacent to the actual treatment room for patients, the Dresden proton therapy facility enables this unique research work to advance in an interdisciplinary team.

The prototype's development and installation were made possible in close cooperation with international industry partners. ASG Superconductors in Genoa, Italy manufactured the MRI device, while MagnetTx Oncology Solutions in Edmonton, Canada designed the rotating gantry. Company representatives from both manufacturers were present at the launch ceremony.

Michael Kretschmer, Minister-President of Saxony: "The inauguration of this globally unique combination of an MRI machine with a proton therapy facility marks a milestone for Saxony as a center for science. It is an example of the potential and knowledge available here. At the same time, it becomes clear how we can achieve great things together through strong international collaborations. It is positive and right that the Free State of Saxony specifically supports innovative projects such as this one at the university hospital."

Sebastian Gemkow, Saxon State Minister for Science: "In order to improve therapies in the long term and to exploit the potential of modern technology, innovative science and research are needed. If, as is the case here, different technological disciplines are able to work closely together with medical professionals, this is an enormous advantage and at the same time a great benefit. The new prototype proves that even the impossible is possible. That is something we can be proud of together."

Prof. Michael Albrecht, University Hospital Dresden, Medical Director: "What is special about the Dresden University Medical Center is the close connection between patient care and science. We have always placed a particular focus on innovative, modern, therapeutic approaches — especially in oncology. The innovative leap that we are now making with the new prototype demonstrates that we are always at the forefront. A role we can only assume thanks to the positive collaboration with our scientific and industrial partners. This is the only way flagship projects like this are possible."

Radiation-based cancer research is one of the HZDR's major fields of research. We conduct research for healing. Our particular concern is to quickly set research findings into practice for the benefit of patients. We are fulfilling this aspiration precisely with the new prototype."

Prof. Sebastian M. Schmidt, Helmholtz-Zentrum Dresden-Rossendorf, Scientific Director

Prof. Esther Troost, Dean of the School of Medicine Dresden and Director of the Clinic and Polyclinic for Radiotherapy and Radiation Oncology: "The research alliance of OncoRay - National Center for Radiation Research in Oncology - sees itself as a cross-institutional research platform for medical radiation research in Dresden with a particular focus on translational research. The prototype that has now been inaugurated fits perfectly into this special research environment. Our research goal is to improve cancer treatment through biologically individualized and technologically optimized radiotherapy. We also hope to achieve such improvement with the world's first MRI-guided proton therapy developed here."

Source:

Technische Universitaet Dresden

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