HCB News (www.dotmed.com/news) is a leading news source for proton therapy current events. In this section we recap some of the highest-impact stories we’ve published over the last six months.

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Court finds Aetna wrong for refusing proton therapy coverage
A federal judge ruled in February that Aetna wrongfully denied patients access to proton therapy.

An advanced form of radiation therapy, proton therapy is designed to better target and eradicate tumors with less risk of damaging healthy tissue and creating short-term and long-term side effects in patients.

The insurer, which argued that the treatment was experimental and investigational, failed to justify how proton therapy did not align with its definition of what is “medically necessary,” according to Judge Kenneth Marra of the U.S. District Court for the Southern District of Florida on Thursday.

Marra ruled partially in favor of plaintiffs Sharon Prolow and Mark Lemmerman, who both sought coverage for proton beam radiation therapy for non-metastatic breast and prostate cancer, respectively, according to Modern Healthcare.

"Given the extensive medical literature, detailed medical records, treatment plans and compelling evidence of individual risk factors supplied by Ms. Prolow's and Mr. Lemmerman's treating physicians, the court concludes that the recommendations of the plaintiffs' physicians reflected prudent clinical judgment," said Marra in his ruling.

He did, however, say it was unnecessary to take up the claim that Aetna violated the Employee Retirement Income Security Act by denying coverage. ERISA refers to a set of federal laws that are part of the Employee Retirement Income Security Act of 1974. Under this Act, employers pay employer-based plans to create clinical guidelines for judging and approving claims such as PT. Many insurance providers often use these guidelines as grounds for its approvals and denials, and all claims and appeals processes must be exhausted before a civil lawsuit can be filed.

Prolow had filed the suit on behalf of beneficiaries of ERISA plans and claimed that Aetna violated its fiduciary obligations when it denied coverage for proton beam radiation therapy for breast cancer.

Is proton CT superior to conventional CT for planning proton therapy?
Proton therapy manufacturer ProtonVDA and researchers at Loyola University Stritch School of Medicine, Northern Illinois University and Loma Linda University published findings in January determining proton CT reduced range uncertainties, which could allow radiation oncologists to potentially use smaller margins around tumors and more precisely deliver proton radiation to cancer sites.

The reason for this is that using X-ray CT requires the CT Hounsfield units to be converted into proton relative stopping power (RSP) to calculate proton range in the patient and generate a plan. This leads to uncertainties, which necessitates the need for wider margins. Proton CT directly measures RSP, which decreases uncertainties and may allow for smaller margins.

While small reductions in dose associated with a single scan are not likely to cause harm, the 10- to 100-fold decrease brought on by proton CT could enable scans to be repeated regularly, according to senior author James Welsh, a professor of radiation oncology at Loyola University Stritch School of Medicine. “Thus, if there is a clinical benefit to proton radiography and proton CT, the studies can be repeated as often as necessary to maximize such benefit — without the fear that such benefits will be negated by any detrimental effects from radiation dose,” he told Physics World.

For their analysis, the researchers used ProtonVDA pRAD, a prototype clinical proton imaging system, and X-ray CT, and then compared the different RSP values. To validate the accuracy of proton CT, they imaged a cylindrical phantom with eight tissue-equivalent inserts.

The researchers plan to conduct more quantitative dose comparisons, as well as evaluate the automation of data acquisition, optical tracking of the rotation, integration with an upright treatment system and testing of treatment beams and film stacks to better understand the potential of proton CT for low-dose treatment planning.

Varian completes world’s first human FLASH therapy trial
Varian, a Siemens Healthineers company, and the Cincinnati Children's/UC Health Proton Therapy Center completed treatment in the world's first human clinical trial for FLASH therapy last October.

The trial enrolled 10 patients with bone metastases in the extremities, starting in November 2020. It used Varian's ProBeam to deliver radiation therapy with protons at ultra-high dose rates. The trial evaluated clinical workflow feasibility and monitored side effects related to the treatment.

So far, the trial found no side effects directly related to therapy, and the ProBeam in research mode has worked as expected, Sharma said.

"For the first time, we showed that FLASH could be delivered safely," Sharma said.

The patients were given a radiation dose similar to the one used in conventional radiotherapy, but at a higher speed, typically less than one second and potentially over 100 times faster than standard treatments.

"We found that when you gave the dose much more quickly you seem to spare normal tissue," Sharma said.

The trial assessed pain control, a measure of tumor response that Sharma said the patients reported receiving.

The study was designed by leaders at Varian and multiple centers in the FlashForward Consortium, a 20-member group of institutions from around the world, which includes experts in radiation oncology, translational sciences and medical physics.

Tampa Bay in Florida to receive first proton therapy center
The last of Florida’s major markets is set to have its own proton therapy center in the next few years.

Tampa General Hospital announced in October it had partnered with the Florida Cancer Specialists & Research Institute, Proton Therapy Partners, and Florida Urology Partners to build a free-standing center in Tampa Bay. Construction is expected to begin in the second quarter of 2022. Which specific vendors will be in charge of supplying the proton therapy system and other equipment is still under discussion.

"Its specificity of delivery allows us to treat hard to reach tumors, those wrapped around critical organs, and tumors that have come back after radiation. It's also the safest form of radiation we have to offer our pediatric and young adult patients suffering from cancer,” said Dr. Richard Tuli, chief of radiation oncology in the USF Health Morsani College of Medicine at the University of South Florida and Tampa General Hospital, in a statement.

The Cancer Institute at Tampa General will manage the new center, which will provide personalized care from one access point and in a free-standing location, as opposed to in a single provider facility.

In addition to reducing complications, risk of secondary cancers and short- and long-term toxicities, proton therapy increases disease control for aggressive cancers at the base of the skull; reduces impacts on taste, nausea and painful changes to the mouth; and is able to treat a wide range of adult cancers, from breast, to head and neck, to prostate cancer, and pediatric brain and spinal tumors.

RaySearch, Mevion explore new approach for delivering FLASH proton therapy
RaySearch Laboratories and Mevion Medical Systems announced in October they were developing advanced treatment planning approaches to deliver FLASH therapy on Mevion’s S250i Proton Therapy System with HYPERSCAN.

FLASH therapy is an advanced form of radiotherapy currently under investigation. It is designed to deliver a noninvasive, ultra-high dose of radiation in less than one second to treat tumors effectively, while sparing healthy tissue. For their endeavor, RaySearch and Mevion are focused on FLASH intensity modulated proton therapy, an approach that alters proton beams to conform to the shape of tumors. It then applies multiple small proton beams to varying levels of intensity to precisely destroy the tumor.

FLASH therapies require sufficient dose coverage for large tumor volumes, which often are hundreds of cubic centimeters. Combined with the complexity of target shapes and constraints for surrounding organs at risk, this makes single-field FLASH treatments unlikely to provide acceptable dosimetric distribution relative to conventional treatment plans. To address this, Mevion and RaySearch have developed a "merged-field" technique that basically stitches together smaller fields to allow for FLASH doses to be delivered at a rate where the large volume is covered while surrounding organs are spared.

"Our collaboration with RayStation will build upon this technique to develop the temporal and spatial modeling necessary to facilitate optimal target conformality and normal tissue sparing," Daniel Owen, R&D clinical engineer at Mevion, told HCB News.

The approach starts out by applying adjacent intensity-modulated small volumes at FLASH dose rates separately and then combining the individual small volumes to create a single large volume that can apply treatment effectively, while still sparing normal tissue. It is expected to combine both IMPT and FLASH into one delivery system, with each volume applied at FLASH dose rates that complement Mevion’s system.

Proton therapy trial to advance esophageal cancer treatment
Spread across Europe, 19 industry and academic partners have launched a large-scale, clinical trial aimed at extending the reach of proton therapy and tailoring patient selection to those who are likely to benefit from it the most.

The randomized controlled ProtectTrial will oversee the use of proton therapy on approximately 400 patients with esophageal cancer, with the aim of improving access to PT for such patients. At the same time, researchers involved will evaluate selection criteria and create shared reimbursement guidelines that will better ensure proton therapy is offered to patients upon whom it can have the most significant impact across cancer indications.

“This significant project has the potential to produce high-quality clinical data on the benefits of proton therapy. As our understanding of proton therapy’s efficacy grows, we believe this collaboration will help to define guidelines and selection criteria to make proton therapy more accessible to the patients who could benefit,” said Olivier Legrain, chief executive officer of IBA, in an August statement.

The trial is the first European particle research project to consist of both public and private members. Included are 12 proton therapy centers, 17 academic partners, two leading industry partners and more than 30 clinical trial sites across eight countries. The trial will be carried out at Aarhus University in Denmark and headed by professor Cai Grau.

For esophageal cancer, the trial will assess the benefits of proton therapy in a trimodality treatment of radiotherapy, chemotherapy and surgery. This strategy will compare the clinical outcomes of PT and state-of-the-art photon radiotherapy for locally advanced esophageal cancer. The aim is to produce data that can help form European guidelines on the use of PT for the disease, which has a relatively high occurrence rate and requires complex multi-modality treatment. It also has significant morbidity.

Mayo Clinic invests $200 million in proton therapy expansion
Mayo Clinic announced in August it is putting forth $200 million for a 110,000 square-foot expansion of its proton therapy program in Rochester.

With a planned opening in 2025, the extension is expected to free up space for 900 more patients annually and create 117 new jobs. It will include two new treatment rooms with in-room imaging and pencil beam scanning.

"We have experienced increasing demand for proton therapy despite incorporating efficiencies in treatment and delivery, scheduling and fractionation. We anticipate that the need and indications for proton therapy will continue to increase, especially for the complex patient cohorts we see at Mayo Clinic,” Dr. Nadia Laack, chair of the department of radiation oncology at Mayo Clinic in Rochester, told HCB News.

Pencil beam scanning makes targeting and delivering proton therapy to tumors more precise and with lower doses, which reduces toxicity and negative side effects. The expansion will also include state-of-the-art in-room X-ray and CT-imaging, as well as additional imaging resources for precise radiation planning, including MR and other advanced imaging systems for tumor localization.

Site preparation is expected to begin in November and includes relocation of utility tunnels and pedestrian subways. Building construction is scheduled to start in late 2022. The work will not interfere with current proton therapy services.

"Our plan also includes the opportunity to incorporate technical upgrades as they become available in both new and existing facilities in the future,” said Laack.

Superconducting 'bending magnet' could slash proton therapy cost, footprint
A new magnet designed by Japanese researchers could someday dramatically reduce the footprint of proton therapy systems and make them less expensive.

B dot Medical, a startup focused on developing an ultra-compact proton therapy system, revealed in June it had designed a superconducting bending magnet that is capable of generating a high magnetic field. The system consists of a proprietary “non-rotating gantry” that is made possible by combining technology to bend the proton beam and technology for optimizing the magnetic field shape.

"Our system would be about half the size of conventional proton therapy systems. The height, in particular, is expected to be reduced to 4 meters from the previous 10 meters. In addition to being inexpensive, our system does not require the construction of a dedicated building, which leads to cost reductions when it is installed," Takuji Furukawa, president and CEO of B dot Medical, told HCB News.

The proton beam bending technology is accelerated to more than 70% the speed of light, inside a superconducting magnet with a high magnetic field. The technology enables the proton beam to converge to a single point no matter where it enters the magnet.

The researchers next plan to perform a pattern operation test to quickly control the strong magnetic field generated by the superconducting magnet. They will then perform a proton beam test before applying for Pharmaceutical and Medical Device Act approval in Japan.

"We believe that by making our system smaller and less expensive, installing a proton therapy system will be easier and hospitals that have been using X-ray therapy will be able to provide proton therapy," said Furukawa. "This will allow more cancer patients to choose proton therapy, which is currently available only to a limited number of patients."

Prototype in the works for incorporating real-time MR imaging for proton therapy
German researchers are building what they say is the first prototype of a proton therapy system capable of tracking moving tumors with MR imaging, potentially paving the way for better targeted treatment.

"Real-time magnetic resonance imaging has the unique ability to provide excellent soft-tissue contrast in addition to fast imaging that captures organ motion," Dr. Aswin Hoffmann, research group leader of experimental MR-integrated Proton Therapy, Institute of Radiooncology – OncoRay, told HCB News last April. "Typical examples are cancers that could benefit are those of the liver, pancreas, oesophagus, rectum, kidney, adrenal and cervix."

To see if real-time imaging could synchronize the proton beam to tumor motion, the researchers combined a rotating, open low-field 0.22 Tesla MR scanner designed by ASG Superconductors for the LINAC-MR system from Alberta Health Services, with an actively scanned proton beam at OncoRay. The results showed strong MR image quality during irradiation with a static beam.

At some point, Hoffmann plans to build a prototype that may be used clinically. ASG Superconductors will produce the mid-field-strength open 0.5 Tesla MR device, which will be specifically adapted to the requirements of real-time MR-guided radiation therapy by the Alberta Health Services LINAC-MR group and its spin-off company MagnetTx Oncology Solutions.

"New capabilities provided by MR-integrated proton therapy include an increased targeting accuracy for the treatment of moving tumors, an expansion of the range of possible organs which can be targeted with increased precision and less normal-tissue side effects, and last but not least, this technique will inform the repurposing of radiation therapy to address other pathologies, such as arrhytmic myocardial tissue ablation with highest precision comparable to surgical procedures," Hoffmann told HCB News.

Demand for proton therapy systems half of what it was five years ago: report
Demand for new proton therapy systems is half of what it was in 2015, with the market slowing by 3% each year since 2018, according to MEDraysintell’s Proton Therapy World Market Report & Directory, Edition 2021, which came out last March.

The slowdown has been attributed in the past to several factors, including negative publicity and cost barriers to treatment. One of the biggest challenges has been resistance from health authorities and private insurers to reimburse providers for the treatment.

“Proton therapy, like any business in the medical field, is directly affected by reimbursement policies, which differ in each country or region worldwide. Generally, countries that have a proton therapy center have a reimbursement policy for proton therapy implemented by their national health insurance system and/or covered by private insurances,” Paul-Emmanuel Goethals, co-founder of MEDraysintell, told HCB News.

Fewer than 280 particle therapy treatment rooms — most of which are PT-based — were available for patients as of February 2021. There are 0.4 particle therapy treatment rooms per ten million people, compared to a rough equivalent of 20 radiotherapy systems worldwide, with proton therapy making up 2% of all external radiotherapy installations worldwide.

Even demand for single-room versus multi-room PT systems has stayed the same, with the 2020 order book for new particle therapy facilities showing 45% for single-room proton therapy, 45% for multi-rooms, and 10% for heavy-ion therapy centers. These proportions have remained the same as the 2013 – 2020 period, according to Goethals.

Compared to 2021, 2015 saw high market activity for PT that continued until mid-2016, when it began to slowly dip. Global investment in particle therapy, including carbon and proton, was almost 20% lower in 2018 than in 2017 and 62% lower than in 2015.