PET-CT Hybrid Scanners Growing Up
hiit040305.jpgPET-CT has matured quickly from the newest imaging solution to the gold standard for a variety of oncologic indications. “We could not practice oncology without PET-CT,” affirms Shyam Paryani, MD, director of Florida Radiation Oncology Group (F.R.O.G.) of Jacksonville, Fla.

PET-CT packs its punch by marrying functional and anatomic imaging to create a sum greater than its parts. “PET provides the ability to determine very accurately whether or not metastatic disease is present and determines the extent of disease. PET is more accurate than other modalities, and the addition of [anatomic CT images] makes it very accurate,” explains R. Edward Coleman, director of the nuclear medicine division at Duke University in Durham, N.C. Studies show that PET-CT has a major impact on management of 15 to 50 percent of patients scanned. Patients may be upstaged or downstaged and shifted to surgery, chemotherapy or radiation therapy depending on PET-CT results. Francois Benard, MD, associate professor of nuclear medicine at Sherbrooke University Medical Center in Quebec, adds to the list of benefits. Increased diagnostic precision with Philips Medical Systems Gemini PET-CT scanner translates into fewer equivocal results, decreased need for ancillary tests and fewer delays in diagnosis.

Although PET-CT has produced some powerful results in oncology, researchers (and payors) are still determining the full extent of its clinical utility. Currently, Medicare covers PET-CT for multiple indications: lung, esophageal, gynecological, thyroid, colorectal, advanced breast and head and neck cancers and lymphoma and melanoma. But the Feds, with the help of the Academy of Molecular Imaging and American College of Radiology, are studying expanded coverage for PET and PET-CT scans.

The Centers for Medicare and Medicaid Services (CMS) recently commenced a large-scale project to determine if it should cover PET for additional oncologic applications. The National Oncologic PET Registry (NOPR) started covering PET scans for non-approved indications among Medicare patients early this year.

As CMS gathers data, providers can plan for a successful PET-CT deployment or improve a current deployment by going beyond the clinical and addressing the triumvirate of the PET-CT business: finances and operational planning, IT and marketing.

Mobile PET-CT in practice

F.R.O.G. deployed Siemens Medical Solutions biograph duo PET-CT scanner three years ago and has seen the scanner emerge as a standard of care. Approximately 60 percent of PET-CT patients undergo a hybrid scan, and others receive a stand-alone CT on the CT unit of the PET-CT. The practice relies on PET-CT for all treatment planning. “We position the patient in the same anatomical position on the flat table and use the same immobilization devices and built-in lasers,” says Paryani. More accurate placement translates into a more precisely aimed radiation beam. And the combination of PET and CT more clearly defines abnormal areas, allowing physicians to restrict the beam and spare normal tissue.

As PET-CT volumes grew, F.R.O.G. added a biograph 6 PET-CT scanner in August 2005. Both units are mobile and travel among the practice’s six sites. “We’ve pioneered the mobile model. This model overcomes cost, which is a major barrier to entry in the PET-CT market,” explains Paryani.

Mobile scanning is not without its challenges. Staff travels with the van, essentially working in a new office every day. Ensuring that fluorodeoxyglucose (FDG) arrives at the right place at the right time adds a second logistical challenge. F.R.O.G. implemented a rigorous logistics program to address FDG dosing, scheduling and staffing.

The final challenge with mobile PET-CT is IT. Initially, radiologists traveled with the van or read scans at the end of the day, but as volumes grew, F.R.O.G. required a system to transfer datasets to a central facility for interpretation. The group upgraded from a broadband network to T1 lines, so that it could easily move studies that average 175 megabytes. Image viewing was the next hurdle. “Most PACS are not designed for multiple remote connections,” notes Paryani. F.R.O.G. deployed Numa, Inc.’s NumaStore mini-PACS for PET-CT and nuclear medicine, which enables transfer and remote access of PET-CT studies.

Succeeding in the PET-CT business

Southwoods X-Ray and Open MRI in Youngstown, Ohio, deployed a Hitachi Sceptre P3 PET-CT scanner late in 2004. The full-service imaging practice had considered PET-CT for several years and decided to enter the market to remain competitive. For more than a year, the practice has relied on the combined system for cancer detection and monitoring and CT scans; however, PET-CT volume has fallen a little short of projections, says Medical Director Steven Aubel, MD.

Aubel cites several reasons for the lower than expected volume. “Physicians aren’t as familiar with PET-CT as they are with other modalities. Our initial marketing plan focused on technical applications not the benefits of PET-CT for the referring physicians’ practices,” explains Aubel.
Southwoods’ second tier marketing program will better describe how PET-CT can benefit referring physicians and their patients. The educational effort also will outline inappropriate indications for PET-CT.

Aubel suggests practices considering PET-CT complete a thorough market analysis of local physicians’ needs including how PET or PET-CT is used. Success, however, transcends a solid business plan.

IT is a key consideration. Practices need to develop long-term image storage plans and a method for sharing images with referring physicians. Currently, Southwoods sends physicians a hard copy of key PET images and a CD with a report and all images. Web-based viewing could improve referring physician satisfaction and facilitate timely report distribution, says Aubel. Other IT requirements include:
  • A full DICOM-capable scanner with modality worklist. (If a buyer fails to specify modality worklist in the purchase agreement each scan could require multiple RIS entries, which disrupts workflow.)
  • A thorough assessment of workstation placement. A single workstation located at the scanner could slow radiologists by forcing them to move back and forth between workstations. Integrated PET-CT fusion software on the PACS workstation allows the PACS workstation to double as PET-CT viewing station, but not all software provides full functionality.
Benard of Sherbrooke University Medical Center says image display is a challenge with PET-CT. The center’s Fujifilm Synapse PACS serves storage and image retrieval needs quite well, but like other PACS displays, it is not optimized for PET-CT images. The temporary solution is to use the PACS to transmit screen captures of key images — coronal slices and 3D projections — in addition to transaxial images to provide referring physicians with a more complete diagnostic picture.

PET-CT in evolution

Duke University has relied on GE Healthcare’s Discovery LS PET-CT scanner for oncology applications for nearly three years. “PET-CT is an evolving standard of care,” says Coleman. Coleman predicts that additional cancers could be covered as the Medicare registry gathers data. “In the future, PET will be used to monitor therapy. Studies show that PET can predict the effectiveness of therapy early during the course of treatment,” states Coleman. For example, currently, lymphoma is typically treated with six cycles of therapy with an evaluation of its effectiveness after four or five cycles. But data demonstrate that PET can determine effectiveness after only one or two cycles, which reduces the toxicity and cost of non-effective therapy. The same model can be applied to breast cancer.

Other PET-CT advances will come on the tracer front as the era molecular imaging produces more specific agents, says Coleman. F18 fluoride could be used as a bone scanning agent, which would shift bone scans to PET and PET-CT scanners. Fluorothymidine (FLT) has the potential to analyze tumor proliferation, and F18 fluorocholine could assess prostate cancer progression.

PACS improvements will bolster the utility of PET-CT, too. One of the current limitations is that PACS does not easily display fused PET-CT images. CT images are gray, and PET is superimposed in color. “PACS vendors will overcome this,” asserts Coleman.

Finally, PET-CT could be applied beyond oncology. “Data suggest that PET could analyze infectious processes and inflammatory disease, but more studies are needed to determine its utility in the area,” says Coleman.

While PET-CT has grown up, the technology and applications are still maturing as researchers work to uncover new applications and improved tracers. PET-CT and PACS vendors are hard at work as well, developing better systems for displaying, transferring and storing PET-CT data. In practice, PET-CT sites can improve operations and the bottom line by staying on top of new clinical applications, IT and operational issues and marketing.

Best Practices in PET-CT

R. Edward Coleman, director of the nuclear medicine division at Duke University in Durham, N.C., and a leader in the PET-CT field provides insights into how to implement PET-CT for maximum gains.

  1. Implement systems and processes to make images readily available to physicians and patients.
  2. Share results with referring physicians in a timely manner.
  3. Make all images available to referring physicians. Robust image distribution serves two purposes: it helps clinicians understand the reports and markets the PET-CT program.