Proton and particle therapy facilities are a complex balance of technical and medical equipment, processes, and human factors, and require significant resources and expertise to execute successfully. The key aspects to consider are the following: clinical and technical requirements, design and construction, and cost and schedule.

Clinical and technical requirements

Proton therapy is usually an expansion of an ongoing radiation therapy program or practice, whether integrated into an existing facility, or constructed as a new freestanding building. This requires a series of decisions about the range of the program within the context of cancer care, types of technology (both initial and future), and the patient experience.

Basic clinical decisions include:

• patient volume and case mix (adults/pediatric, case complexity)

• number of treatment rooms (fixed, isocentric gantry)

• imaging modalities for diagnosis, treatment planning, and position verification

• patient experience and healing environments

• initial capacity, ability to expand in the future

• on-site space for clinical, medical physics, administrative functions, and

• integration of physics and clinical research.

Technical factors include:

• accelerator type (cyclotron/synchrotron)

• equipment manufacturer

• established vs. emerging technology

• integration of position imaging

• complexity of facility required to house the proton equipment, and

• long-term technical support.

Clinical and technical requirements, design and construction, and cost and schedule are key aspects to consider with a proton and particle therapy facility. photos/courtesy MD Anderson Proton Therapy Center

Design and construction

The complexity and precision of proton technology presents numerous design and construction challenges, from shielding to tolerances to sub-millimeter structural movement. Centers also must be designed for high-efficiency operations while remaining flexible enough to accommodate technology advances without sacrificing the patient experience.

The technologies for proton beam delivery and control, patient alignment, monitoring, and safety systems come together in the treatment rooms, which are inherently compact spaces into which a significant amount of equipment must be carefully integrated. Proton technologies are rapidly evolving to support image-guided and intensity-modulated proton therapy. Developments in robotics present opportunities for new approaches to patient immobilization, positioning, and verification. The clinical value of these developments lies in the potential for improved treatment accuracy and increased patient throughput.

Shielding mass and frequent below-grade locations typically challenge radiation therapy facilities to be patient-friendly. Balancing shielding cost with the benefits of a grade-level location, including light, openness, and comfort, can make the experience less institutional in feel and more reassuring to patients and families focused on the physical and emotional challenges of cancer treatment and recovery.

Critical factors for success include:

• design and construction team experience

• early development of equipment interface documentation

• early development of shielding requirements and dimensions

• adequate site space and access for equipment installation

• flexibility in facility design for evolving technology (both treatment and imaging), and

• careful three-dimensional planning.

Success in the design and construction process also relies on the assembly of the full project team at inception:

• architect, structural engineer, mechanical/electrical engineer

• construction manager

• shielding consultant

• equipment manufacturer

• clinical and administrative staff, and

• financing and/or development entity.

Cost and schedule

Proton facilities are unusually costly compared to typical health care projects; the proton equipment alone represents as much as one-half the total capital investment needed. By comparison, building construction costs (recently in the range of $400 to $600 per square foot) represent only about one-third of the total investment.

A typical project schedule from preliminary planning through first patient treatment may require 2.5 to 4 years based on a number of variables. An appropriate site and financing must be secured, regulatory approvals identified, and the equipment vendor selected. Standard construction sequencing practices must be significantly modified to make portions of the facility ready for the use of the vendor early in construction. The proton equipment manufacturer requires an additional 12 to 18 months after substantial completion for calibrating and testing before the facility is ready for final commissioning and patient treatment.

Erik Mollo-Christensen, AIA, is a principal with Tsoi/Kobus and Associates Inc. in Cambridge, Mass., and has been designing proton therapy facilities for almost 20 years, including six of the nine operating centers in the U.S. His projects include Massachusetts General Hospital in Boston, The University of Texas MD Anderson Cancer Center in Houston, and the University of Pennsylvania Health System in Philadelphia, and range from freestanding centers to fully integrated cancer center facilities.

News Extra

Designing a proton therapy unit in existing facilities and urban settings is a challenge. Having a shielding design consultant on board early in the process is essential; this will help streamline the entire process from start to finish. A focused contributor will understand the complexities of shielding, along with the line of materials required to achieve the most cost-effective and space-conscious solutions. Sponsored by NELCO