By Dr. Joern Meissner

Access to proton therapy for eligible patients remains a significant challenge. Astonishingly, according to IBA, a mere 2.2% of U.S. patients whose health insurance covers proton therapy (ASTRO Group 1) actually receive this advanced treatment. The global scenario is even more staggering.

So, why is there a pervasive lack of access to proton therapy, despite its recognized effectiveness? Let's explore the landscape of the ASTRO 2023 exhibition to gain some valuable insights.

Among the proton therapy equipment vendors, IBA claimed the spotlight with the largest booth, closely followed by Mevion, Leo Cancer Care, and P-Cure. Surprisingly, Hitachi, a prominent player in proton and carbon therapy, had a rather modest booth, roughly similar in size to B-dot Medical. Sumitomo did not have a booth presence. Varian, Elekta, and RaySearch exhibited sizeable booths with dedicated areas for proton therapy planning. Several other exhibitors offered services, dosimetry equipment, and support to the proton/carbon therapy sector.

But does this accurately reflect the state of the industry? Perhaps a more indicative performance metric is the number of new facilities in development. Currently, the U.S. boasts 43 operational proton therapy centers, with over six under development. On a global scale, more than 120 proton and carbon therapy centers are currently in operation.

IBA stands as the undisputed global leader in proton therapy equipment, boasting an install base of over 75 centers, particularly following Varian Medical Systems' decision in 2022 to halt the sale of new proton therapy systems. IBA's recent win of a 10-treatment-room contract in Spain, thanks to the Amancio Ortega Foundation's contribution to the Spanish National Health System, further cements their leading position. Additionally, IBA recently made sales in Israel and China, expanding their footprint.

Hitachi, despite its small booth at ASTRO, possesses an impressive global presence with 15 proton or carbon/hybrid facilities in operation or under construction outside of Japan, along with 18 facilities within Japan itself.

Mevion, with approximately 15 centers, of which four are under construction, predominantly focuses on the U.S. and Chinese markets. When asked about potential expansion into other regions, Mevion's strategy revolves around considering service synergies before making the leap. Worth noting, most of Mevion's centers feature gantry installations, with the exception of Stanford.

P-Cure currently has one clinical trial center operational in Israel. While ProTom did not exhibit at ASTRO I discussed their progress in Adelaide, Australia, with them during a meeting. The Bragg Center is continuing the works now. Varian also has ongoing developments in Norway, the U.S., Japan, and Indonesia.

In total, the rate of new facility development has slowed down, partly due to the impact of the COVID-19 pandemic, which caused a drop of up to 30% in patient numbers at existing centers. This discrepancy with cancer incidence rates raised concerns among investors. The complex landscape of reimbursement schemes further hindered financing even for centers with promising business plans.

The capital cost of proton therapy emerges as the most frequently cited hurdle to patient access. Encouragingly, significant strides have been made to reduce system size and enhance clinical treatment quality. For instance, the Mevion S250i proton therapy system is notably more compact than the IBA ProteusOne. The Mevion FIT system, co-developed with Leo Cancer Care, represents a leap toward cost reduction and aims to fit within a linac vault, potentially serving as a linac replacement.

Leo Cancer Care has been the driver behind the Mevion FIT system. They have developed the upright treatment system “Marie” and tirelessly explain the clinical benefits of reduced organ motion, the added patient experience benefit, and the economic advantages versus a legacy gantry system. Leo Cancer Care has also has announced strategic collaborations with THERYQ for Very High Energy Electron radiation therapy for FLASH, and with Aviko Radiopharmaceuticals and Neutron Therapeutics for Boron Neutron Capture Therapy.

While Leo Cancer Care has the FDA 510(k) clearance pending on the upright treatment system, the complete and integrated Mevion FIT system is not yet available for clinical use.

After several years of development, P-Cure has introduced an upright proton therapy Adaptive Proton Therapy Solution, designed to fit into linac vaults. This October marked the first ASTRO appearance since P-Cure received FDA approval for its system. Notably, P-Cure estimates a cost roughly half that of legacy gantry systems, coupled with reduced maintenance expenses. P-Cure currently markets its system in Israel and the U.S., with plans to expand into other regions.

Mevion FIT remains somewhat smaller than P-Cure's Adaptive Proton Therapy Solution. Both systems are engineered to fit within existing linac vaults, albeit requiring some additional floor space for auxiliary systems. Each installation necessitates a feasibility assessment to determine necessary changes to shielding walls, mechanical, and electrical systems.

Leo Cancer Care and P-Cure both assert that upright treatment offers benefits to patients, particularly for head and neck, lung, breast, chest, liver, pancreatic, abdominal, and prostate indications. These advantages include enhanced patient comfort and reduced organ motion during treatment. While the number of indications best treated upright versus supine remains debated, it ranges from 30% to 70%, depending on who you ask.

As we navigate the exhibition hall, it's evident that the future of proton therapy is dynamic and evolving. B-dot Medical Inc. introduces a compact gantry solution that rotates the beam around the patient through magnetic field deflection, eliminating the need for heavy moving parts. While this innovation promises to be the smallest gantry solution that can fit into a linac vault, it is not yet available for clinical use.

Could such advancements in size reduction and cost-efficiency be the key to expanding access to proton therapy? Time will tell, especially if these streamlined systems pave the way for future beam delivery modalities like FLASH or Arc therapy. However, it's essential to consider pediatric patients' needs, as treating an anesthetized patient in an upright position presents challenges.

Field size, field matching, and beam properties are also vital parameters to monitor. While the data from upright systems suggest efficacy for many indications, there remains a need for more complex systems that support supine position treatment with a rotating gantry.

In conclusion, the field of proton therapy is advancing, and various innovations hold the potential to enhance access and cost-effectiveness. The future may see proton therapy as an increasingly accessible and efficient cancer treatment option, with benefits for patients and healthcare providers alike.

About Meissner Consulting: Dr. Joern Meissner, a seasoned expert with over 25 years of experience in proton therapy, focuses on enabling performance and cost efficiency. With extensive project experience in the U.S., Europe, and Southeast Asia, he has managed proton therapy projects worldwide. Dr. Meissner is known for his contributions to radiation safety and has played a pivotal role in various medical facility projects involving particle accelerators. After completing his Ph.D. in nuclear physics, he began his career at IBA. In 2001 he founded Meissner Consulting and has been involved in the development and installation of proton therapy systems. His consultancy services extend to industrial and medical facilities, including radioisotope production for theranostics.