CONSTRUCTING A STATE-OF-THE-ART CANCER CENTER
The Center for Cancer Treatment and Prevention at Stanford University Medical Center is one of the nation's most comprehensive cancer treatment centers, and one of the few to offer a complete array of services under one roof. The $84 million, 225,000-square-foot ambulatory care facility is devoted entirely to cancer care, including radiation oncology, surgery, and outpatient services, as well as research and diagnostic facilities. The building will contain up to seven sophisticated linear accelerators to deliver intensity-modulated radiation.
The building has four floors, including a basement that houses the radiation oncology department. The first and second floors house clinical and administrative areas, exam rooms, and offices. The third floor, still under development, will include operating rooms and associated preoperative and recovery suites. A below-grade, basement-level tunnel connects the Cancer Center to the adjacent Lucile Packard Children's Hospital, and a bridge connects the new building to the third level of the nearby Stanford Hospital. The facility, designed by Bobrow/Thomas and Associates (BTA) of Los Angeles (see Showcase, p. 62), won a design award from Modern Healthcare, whose judges said it “epitomizes patient-focused care.”
Because of the dramatic needs of the building, Rudolph and Sletten, the project's contractor, faced several challenges in building the facility, including installation of the seven sophisticated linear accelerator vaults and coordination of the high-tech mechanical and electrical systems to service the linear accelerator vaults, radiology, and radiation oncology, as well as the rest of the building. Site logistics were particularly problematic because the building site is surrounded on all sides by occupied and operational buildings, including two hospitals (figure 1). Congestion at the site made deliveries of materials and staging of cranes and other equipment difficult. This resulted in special coordination needs and required that some of the work be completed at night so as not to interrupt the day-to-day operations of the neighboring hospitals and medical office buildings.
The contractor had to use larger cranes than normal because of limited access around the perimeter of the building. Because there was no access for a crane on the north, east, or south side of the building, a crane had to be used that could reach from one side of the building to the other to accommodate installation of precast concrete panels on the building skin.
The proximity of the children's hospital to the new cancer center required design of the shoring system, to resist any seismic loads that the existing hospital could potentially place on the system. This entire operation and the associated design were implemented in conjunction with the Office of Statewide Health Planning and Development (OSHPD) to minimize the inconveniences associated with such a large construction project.
One of the biggest challenges at the site was the installation of the linear accelerator vaults. Rudolph and Sletten subcontracted the installation of 1.6 million pounds of lead bricks on the walls, ceilings, and decks above the linear accelerator vaults, to act as a radiation shielding system. Lead-lined Sheetrock and plywood were also installed throughout the Radiation Oncology area in the basement and Radiology on the first level (figure 2). The use of lead was associated with many safety considerations related to its cutting and installation.
Construction workers who were installing the lead were regulator-fit tested to make sure their personal protective respirator equipment was worn and operated properly. Lead was cut within a specially constructed booth equipped with HEPA filters and continuous exhaust to remove the lead particles from the shed and clean the air before it was emitted into the atmosphere. The contractor continuously monitored the air, both inside the linear accelerator rooms and outside, to make sure particulate levels were maintained below allowable limits.
Other construction work included:
Self-performing all the concrete work on the project, including concrete for the foundation and the linear accelerator vaults. Almost 18,000 cubic yards of concrete was placed in and around the building.
Coordinating installation of the 2,500 tons of steel that went into the building.
Installing an on-site thermal-fluid steam-generation system within limited floor space in the basement, to avoid the expense of tying into a central steam plant some distance away.
The use of lead was associated with many safety considerations related to its cutting and installation.
The self-contained steam system delivers steam for heating hot water to the air handler units for humidification, to the sterile process area for sterilizing purposes, and to support the nearly 300 variable air volume (VAV) boxes (essentially, small fans in the supply and return ductwork that help control air flow and temperature in each space).
Constructing seven linear accelerator vaults, including the installation of approximately 200,000 pounds of lead for each linear accelerator, to act as a shielding system. The lead shielding system was supplemented by concrete walls up to 4'11" thick, 10 feet of soil outside the vaults on the building perimeter, and a maze wall design inside the vaults (to buffer the radiation-generating equipment and thus reduce door-shielding requirements).
Coordinating development of a unique foundation system, including spread footings, mat slabs, and grade beams. The foundation system was designed to respond to extreme building loads, including the 1.6 million pounds of lead installed in the building, and the large lateral design loads associated with the linear accelerator vault walls.
Constructing the exterior skin system, the basement-level tunnel, a sunken courtyard, and a three-story atrium that allows light from the roof level into all three floors, including the lobby.
Installing four 90-foot-long, 16-ton trusses that span and support the third-floor light court and extend over the drive-through area and the lobby (figure 3).
Coordinating installation of several different materials on the exterior skin, including a custom-colored, precast concrete panel system, metal panels, plaster, and curtain- and window-wall systems (figure 4). Most of the exterior skin system was installed on a design/build basis, preferable because extreme care had to be taken to ensure that all components of the exterior skin system fit together and that transitions from one material to another were carefully reviewed and completed to avoid any potential water infiltration issues. Weekly coordination meetings were held with all design disciplines and exterior skin contractors.
Designing the shoring system to resist both the forces of the perimeter soil and of the entire force of the children's hospital in the event of an earthquake. The shoring system also enabled construction of the foundation systems without interrupting the continued operation of the adjacent facilities. A great deal of preplanning and research were done to ensure that neither public safety nor the myriad of operational utilities was impacted by the shoring system installation.
Building the Linear Accelerator Vaults
Even though radiation beams are shot at a specific angle from a linear accelerator to attack a tumor, a shielding system must be put in place to deflect all primary and secondary radiation beams from leaving the room. This required the contractor—working in tandem with Stanford University, BTA, and radiation-shielding consultant and physicist Nisy Elizabeth Ipe, PhD—to shield each treatment room accordingly (using, in part, the earth itself as a shielding source, because the linear accelerator vaults are located in the basement). Shielding is frequently done with concrete but, because of the limited space available, the contractor used a combination of concrete and lead for the lateral walls and the ceilings. The concrete walls are approximately five feet thick, with eight inches of lead added to them (figure 5). In addition to the lead that was placed on the walls, lead was also installed along the ceiling, to make sure that no radiation beams would penetrate through the concrete to the floors above.
Medical Equipment Installation and Coordination
Another challenge associated with this project was the coordination required for the installation of new medical equipment, as well as the relocation of existing equipment from the adjacent hospital. Equipment included linear accelerators, a PET/CT, various CT scanners, an HDR/brachytherapy unit, superficial therapies, mammography, and ultrasound, as well as chest x-ray digital-imaging technology. Tremendous amounts of time and effort were spent on proper location and installation of each piece of equipment. Important to the process were frequent meetings between Rudolph and Sletten and Stanford Medical Center staff, allowing staff members to provide critical input on improving the operational aspects of treatment and diagnosis.
The Center for Cancer Treatment and Prevention brings under one roof all of Stanford University's resources for diagnosing and treating cancer. The new center doubles the space previously dedicated to cancer programs in the main hospital complex, and in the process provides a state-of-the-art facility, with patient care and comfort being the primary focus. HD