Weighing Proton Therapy’s Clinical Readiness and Costs

We have two comments on the recent article by Michael Goitein, Antony Lomax, and Eros Pedroni (“Treating Cancer with Protons,” Physics Today September 2002, page 45 ). First, the 5000 uveal melanoma patients that the authors mention were treated at the Harvard University Cyclotron Laboratory (about 3000 patients) and the Paul Scherrer Institute (about 2000), not Massachusetts General Hospital and PSI as stated. Ian Constable and Evangelos Gragoudas at the Massachusetts Eye and Ear Infirmary developed the technique with HCL staff as part of a strong collaboration with MGH’s radiation oncology department. PSI and other proton radiation therapy centers later emulated the technique. The long-term teamwork between physicists and hospital staff, in a small but very coherent group with HCL as its nucleus, led to that and many other developments in proton therapy. ¹

Second, and far more important, the authors’ statement that “[protons] have moved from the laboratory to the clinic” glosses over the problems that have so far attended that move. The difficulties of technology transfer have been, and are still, seriously underestimated by many in positions of responsibility. Techniques that would be pedestrian in a mature high-energy physics lab are difficult in the clinic or in commercial ventures, in which the resources and technical backup are far smaller. It is no accident, for instance, that the 17-year-old magnetic scanning technique ² is currently found only at two large laboratories—PSI and the Laboratory for Heavy-Ion Research (GSI) in Darmstadt, Germany.

A look at the two dedicated proton treatment facilities in the US illustrates the problem. Around 1987, the Loma Linda University Medical Center selected Fermilab to furnish a synchrotron and chose Science Application Industrial Corp (SAIC) as an industrial partner to replicate the technology for other customers. LLUMC also began hiring a technical team and forming the Radiation Research Laboratory (RRL) to provide systems engineering, safety systems, and clinical hardware and software for the treatment rooms. In 1990, the year of the first treatment, LLUMC and SAIC ended their business relationship and RRL became responsible for further development and maintenance.

In time, RRL was reconfigured and is now Optivus Technology Inc, housed about two miles from the therapy center. According to Dave Lesyna, current vice president for engineering, the original staff of about 34 has grown to roughly 60 and comprises 24 engineers of various sorts, 8 service technicians, and 28 managerial and support staff. Those numbers do not include the clinical staff (oncologists, radiation therapists, dosimetrists, medical physicists, machine operators, and support staff) who operate the facility. In essence, starting with Fermilab and SAIC and ending with a significant in-house effort, LLUMC has produced, in one decade, a proton radiation therapy facility that has more than 150 treatment sessions per day and treats more than 1000 patients annually. Furthermore, the technical expertise is available for magnetic scanning, intensity modulated therapy, and similar advances. Optivus markets a proton therapy system based on the LLUMC experience and cleared by the Food and Drug Administration.

MGH went the opposite route. Ion Beam Applications (IBA) was selected as the equipment vendor, and is still responsible for completion of the facility, most of the maintenance, and future upgrades. The hospital assumed responsibility for producing some of the equipment, but, by design, the technical staff on the hospital side is limited to around six people. The time from groundbreaking to first treatment (in November 2001) proved to be six years instead of three because of hardware and software problems. As of March 2003, only half the beam lines shown in figure 2 of the article by Goitein and coauthors were in service. The throughput in the single operational gantry room was about 18 patients per day, less than half the design goal. Overall equipment reliability was about 90%, unacceptably low in a clinical setting. In short, the technical forces demanded by the project were greatly underestimated by both the hospital and the vendor, even though the LLUMC experience was available to them.

Broadly speaking, development of a proton-radiation therapy center can take one of two routes. The hospital can buy major pieces of equipment and retain responsibility for integrating them and procuring additional equipment as needed. Or the hospital can buy a complete turnkey system from a commercial vendor. It is critically important to the future of proton radiation therapy that the personnel requirements be realistically assessed by the responsible party—either the hospital or the turnkey vendor. The next few centers, now on the drawing boards, will be a test.