Image Management for Radiation Therapy

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Managing radiation therapy images for IMRT, IGRT and gated imaging is getting more complex as images increase in number, volume and frequency. Digital image management is the clear answer for the healthcare facility demanding anytime, anywhere, real-time access to images critical to accurate, effective radiation therapy.

Like general radiology, radiation oncology is seeing an explosion in the number and size of images it is acquiring and managing. Consequently, it is increasingly important for radiation therapy departments to evaluate their image viewing and management needs and implement a proactive solution.

Randy Holt, PhD, chief medical physicist at Enloe Medical Center (Chico, Calif.), explains the situation. "Radiation oncology is becoming more and more dependent on imaging for diagnosis and treatment. We're dealing with massive amounts of imaging information." Indeed, some radiation oncology centers are transitioning from two to three port films per week to multiple films a day over the course of an eight-week treatment. The exponential increase in images allows radiation oncology centers to tap into the latest techniques in technology, including IMRT (intensity modulated radiation therapy), IGRT (image guided radiation therapy) and gated imaging. But the increased image volume and more precise treatment protocols present a dilemma. How can films be rapidly accessed, viewed, managed and stored to facilitate efficient and effective clinical decision-making?

In many cases, digital image management provides the answer. Anytime, anywhere, real-time electronic access to patient images carries a number of benefits in the radiation oncology department that include:

  • Improved productivity and workflow
  • Enhanced patient care
  • Reduced costs
  • Enhanced service to referring physicians

REINVENTING WORKFLOW & PATIENT CARE

South Suburban Oncology Center (Quincy, Mass.) implemented Impac's (Mountain View, Calif.) ViewStation image management system 18 months ago and has seen dramatic improvements in workflow and patient care since installing the system.

Administrator Karen Donnellan explains the 'before' situation. "We have two linear accelerators and see 105 to 110 patients a day. It was hard to get port films approved by physicians in a timely manner." Films needed to be physically retrieved and hung; radiation oncologists typically spent anywhere from 30 minutes to two hours at the end of the day reviewing and approving the piles of films that accumulated throughout the day. Donnellan acknowledges, "The situation has improved tenfold with ViewStation." Now, radiation oncologists can review images electronically on their computers throughout the day, easily integrating on-the-spot review into their workflow.

This near-real-time review is one of several ways that electronic image management systems can improve patient care in radiation oncology. Most radiation oncology centers have or are moving toward IMRT and IGRT. Indeed, on-board imaging, gated imaging and 4D treatment is right around the corner. These advances promise to improve patient outcomes but hinge on an ever-increasing amount of imaging data to drive more precise treatment plans.

CUTTING COSTS & ENHANCING EFFICIENCY

Enloe Medical Center has transitioned from the classic approach to radiation oncology, defined by looser, larger treatment fields, to the modern approach, characterized by tighter, more precise fields and increased radiation doses. The department relies on Varian Medical Systems' (Palo Alto, Calif.) VARiS Vision radiation oncology information management system, which includes physician and dosimetrist workstations, radiation oncology management software and electronic charting - to facilitate the modern approach.

Holt explains, "It's important for us to push images to the right people for decision-making. We need to move beyond passive management of images." The center and its satellite handle 50 patients per day and take daily films of all IMRT patients. "We don't have legions of staff to push images in front of physicians, and we can't afford to throw people at the problem. We have to do this with a budget."

Enloe Medical Center relies on the oncology management system to move images to radiation oncologists and enable a more active image management process. The software provides physicians with immediate access to images; any time a physician logs onto any workstation in the building, he is reminded to check films, which streamlines the image review process.

"The software provides access to all previous images for baseline and trending and current images for verification of patient positioning on a day-to-day basis," Holt continues. Both types of images are critical. The verification process is an immediate need as the center moves toward more treatments requiring ever more precise patient positioning. With tighter margins and increased doses, the treatment team needs to tighten its image review process. The system not only integrates and displays the new images, but also provides a range of tools to fine-tune the measurement process. The integrated measurement tools improve on the classic radiation oncology methods of using a ruler and lightbox to determine margins.

Holt says the tracking and trending capabilities can boost productivity and efficiency. The center relies on informatics to track measurements such as patient positioning and procedure lengths and plan accordingly. For example, the department projects how much physicist time it will need for treatment planning. Holt notes, "This type of database mining has allowed us to reduce our staffing requirements by 15 percent."

IMPROVING SERVICE

At South Suburban Radiology, Staff Radiation Oncologist Joseph Barthold, MD, adds to the list of advantages of electronic image management in radiation oncology. Because radiation oncology images are taken at a higher energy than conventional films, the differences between soft tissue and bone can be obscure. Digital images can be modified and enhanced electronically to correct for this issue, allowing radiation oncologists to more accurately identify the field of interest.

"The system has allowed us to serve both our patients and referring physicians much better," Barthold continues. For example, Barthold often receives calls from physicians about previously treated patients with new tumors. Take the not-uncommon scenario of a lung cancer patient whose treatment entailed radiating a number of thoracic vertebrae at full dose and returns one year later with a tumor on the lower spine. Barthold can review the patient's films while on the phone with the referring physician, giving him a quick green light to refer the patient for treatment, if appropriate. This new reality stands in sharp contrast to the old way of doing business; hanging up, dispatching a film clerk to locate films offsite and returning the call several days later.

On the weekend, Barthold and his partners no longer need to spend an entire morning driving to the hospital to review films if a patient's care requires their input. Instead, they can make decisions from home after reviewing films online.

ViewStation also enhances conferencing. Weekly rounds at South Suburban Radiation Oncology are held in a conference room, and images are projected onto a 10-foot screen - a definite improvement over a crowded lightbox. And during the normal course of the day, several members of the team can review images concurrently, enabling the physicist, dosimetrist and radiation oncologist to readily make and implement any necessary changes in the treatment plan.

Finally, day-to-day charting and documentation also is greatly streamlined. Electronic annotation and signatures have replaced the ubiquitous (and non-secure) Post-it notes attached to films, providing an electronic record of patient care.

THE NEW FACE OF RADIATION THERAPY

Over the last year, Jonsson Cancer Center at the University of California Los Angeles, which treats 75 to 80 patients a day, has completely revamped its radiation therapy department, implementing new treatment machines, a record and verify system, a new CT scanner for virtual simulation, electronic portal imaging and digital image management nearly concurrently. Siemens Medical Solutions (Concord, Calif.) Coherence applications serve as the hub of the reinvented department. The Coherence Therapist Workstation allows therapists to capture and manage images electronically and push images throughout the enterprise, and Coherence Oncology Workstations provide the means for physician review of initial and weekly port films.

Medical Physicist Tim Paul explains, "The main advantage with this kind of system is the merging of image management applications and radiotherapy applications. This integration is as essential as the field moves toward image-guided radiation therapy." For example, with Coherence, radiation oncologists can review standard radiation therapy images and integrate multi-modality images in the treatment plan.

Like other sites that have implemented digital image management, Jonsson Cancer Center has realized efficiency and accuracy gains. Now, when DRRs (digitally reconstructed radiographs) and associated port films are sent to the physician for review and alignment, the physician uses integrated image registration tools to calculate offsets in 3D, which speeds the plan approval process and allows therapists to make shifts in patient positioning if necessary. Paul concludes, "Ultimately, we think that these tools will allow us to deliver more accurate treatment. The system will also allow us to spend more time treating patients and less time looking for images." That's because images are always available and can be replaced or transferred nearly instantly if necessary.

IMPLEMENTING ELECTRONIC IMAGE MANAGEMENT

Barthold of South Suburban Oncology Center admits, "Implementing digital image management can be a slightly expensive process that requires some infrastructure [typically computed radiography and image review workstations and software], but we're saving quite bit of money because we've eliminated the dark room, film storage costs and file clerks. It's really very cost-effective if you calculate all of these factors into the equation."

Another potential barrier to electronic image management systems is physician resistance. "I often hear about the one physician in a department who doesn't want to use the system," Donnellan says. "My advice is to make the decision appropriate for the department. It's important to have a plan in place. We started the process slowly, but with a three-month deadline. By the fifth week, all of the patients coming out of the simulator were filmless, and in three months, we pulled the film processor."

Paul recommends that sites transitioning to digital image management develop a plan for workflow changes before implementing a new system. Workflow plans, however, should be fluid because digital solutions incorporate tracking tools that allow centers to identify, troubleshoot and remedy logjams in the process, such as the physician who neglects to review images.

CONCLUSION

Radiation therapy digital image management solutions can allow sites to replace the traditional fragmented radiation therapy process with a seamless process. With a digital solution, the radiation therapy team has instant access to current and prior images, and multi-modality images are easily integrated. In the end, the wide range of integrated tools allows the team to reduce costs, enhance efficiency and workflow and deliver state-of-the-art treatments.

The Storage Issue

The storage capacity of any radiation therapy image management solution hinges on a semi-complex equation. For starters, the healthcare facility or department needs to determine the size of individual images to be stored, and there is significant variability among products. The primary images to be stored include EPIDs (electronic portal imaging device) and CR (computed radiography) images. An individual EPID image from a portal imager can range from 300 to 800 kilobytes in size to two to four megabytes. CR image size also can vary from 300 to 800 kilobytes to two to four megabytes depending on the imaging source. The radiation therapy center also needs to consider CT image size (approximately 0.5 megabytes) and DRR (digitally reconstructed radiograph) size (approximately 0.75 megabytes). Finally, DICOM curve information from a treatment planning system also can require another 4 to 5 megabytes of storage space per image.

After the site obtains the image size for its specific imaging products, the math gets a bit easier. The final variables - number of images and number of patients - should be easily found in-house.

Conventional wisdom for radiation therapy image storage is to implement a scalable server and add drives as needed. While it's now possible and even economical to purchase a 144-gigabyte drive and put six drives in a server, that option may be overkill for most centers. A mid-sized radiation therapy center with two linear accelerators and 20 users can get by with three or four 36 gigabyte drives in a RAID (redundant array of inexpensive disks) five environment. This configuration can satisfy storage needs for up to five years. High volume sites often opt for heavy-duty solutions like a SAN (storage area network) or NAS (network attached storage), which can provide terabytes of space for nearly unlimited storage.