Compromises to radiation oncology networks, like attacks by computer worms or other network disruptions, simply can't happen with patient-critical information such as that contained in radiation therapy plans. That's why networks carrying this vital information must rely on multiple fiber paths, switches with primary and secondary backup and uninterruptible power supplies that won't let them down. Redundancy and resiliency are musts.
'Just in case' is key when maintaining a radiation therapy network, as our examples will show. If you aren't convinced that your radiation therapy network requires special configuration, consider this.
Late in 2003, a major cancer treatment center in the United States encountered a severe disruption in service when their enterprise network was infected by a variant of a Microsoft Windows-based computer "worm." The resulting outbreak caused a denial-of-service attack across the campus data network that severely interfered with information systems for several hours, including the network used to provide radiation treatment for their cancer patients, necessitating the rescheduling of those treatments. How did they make sure they wouldn't be "hit" again? This specialized cancer treatment center configured a special network to support their key radiology devices that is strictly protected from being affected by worms or similar network disruption.
Several factors lend urgency to the importance of having the radiation oncology (rad/onc) network fully functional 24/7, even though treatment is not administered all of those hours. A typical patient receives this highly complex and exacting treatment every day, five days a week for six weeks, although that varies depending on the treatment plan for a particular type of cancer. The treatment planning systems and simulators require nightly back up by the IT department, usually accomplished during the hours when patients are not being treated.
The network pathway begins at the imaging modality used to define the tumor volume and shape, usually a computed tomography scanner. From there, digital images move often through a server to the radiation therapy planning station where physicians, medical physicists and other staff design appropriate treatment parameters, to the linear accelerator (linac) where the radiation beam is delivered to the tumor site and surrounding tissues. Record and verify activity as well as portal imaging to document the treatment delivered round out the rad/onc pathways. Exquisite pinpoint accuracy is critical to target cancerous cells while sparing normal tissues as much as possible.
Shawn McNeeley, medical physicist at Fox Chase Cancer Center in Philadelphia, explains that IMRT (intensity modulated radiation therapy) requires between 40 and 140 separate, individual radiation fields to be downloaded onto the linear accelerator to provide the appropriate treatment devised by the physician, dosimetrist and medical physicist."We're totally dependent on the server and record and verify system to provide the linac with the configuration for doing the treatment," McNeeley says. "Without that, we're dead in the water."Case studies presented here describe how the IT and healthcare professionals of three major cancer centers ensure that their network is always up and running.
Fox Chase Cancer Center in Philadelphia
Robert Gaul, director of voice and data communications, across this three-building enterprise explains their basic networking guidelines direct that any portion of the network infrastructure considered "mission critical" involves up-front design of some amount of redundancy and resiliency.
"Whenever possible, we have configured multiple network paths between critical data hubs or closets," says Gaul. "Our core network closets have multiple fiber paths between them and most of our switches have a primary and a backup or secondary up-link," says Gaul. All mission-critical data closets have UPSs (uninterruptible power supplies) which are connected to emergency power." In the event of a loss of electrical power, back-up generators maintain continuous service.
Fox Chase's Medical Physicist McNeeley explains that they have designed dedicated pathways between treatment delivery components. Data generated by imaging modalities (usually CT) are sent to a record and verify system controlled by a single server. Communication between that server and the linacs is accomplished over a dedicated fiber-optic line that is isolated onto its