Minimally invasive surgery can seem like a dream – or a nightmare. On one hand, such procedures require only a small incision, reducing trauma to the body, shortening recovery time, and costing less for hospitals. On the other hand, without the ability to see directly the target inside the body, a clinician is only as good as the imaging technologies used to guide the procedure.
Now Philips Research is developing an image-guidance workstation that would generate more information than current systems and help surgeons navigate better during minimally invasive procedures. The technology brings together images from computed tomography (CT) scans and ultrasound, and uses an electromagnetic tracking system to pinpoint the position of surgical instruments within the body.
“When we look at how [non-invasive surgical] procedures are done today, we see somewhat of a primitive landscape,” says Guy Shechter, senior research scientist at Philips Research. He says most clinicians use only one type of imaging technology, even though each type has its flaws.
Shechter’s team has been working for two years to develop an image-guidance workstation, and partnered with Brad Wood, an interventional radiologist at the National Institutes of Health, to test the technology in patients.
They have focused on a minimally invasive procedure called radio-frequency ablation (RFA) as a treatment for tumors. During this procedure, cancerous tissue is heated with electricity until it dies. The procedure has become a popular alternative for treating certain cancers without full-blown surgery. But delivering the current to the right location is crucial.
A patient undergoing a radio-frequency ablation procedure would typically undergo several CT scans, first to locate the tumor, then multiple scans to ensure that the ablation probe is inserted in the right place. CT scans provide the clearest picture of the body’s anatomy, but because of the radiation dose, they cannot be performed while a clinician is present.
The Philips workstation eliminates the need for multiple scans by bringing together CT and ultrasound imaging, along with tools that track the position of the surgical instruments.
The patient is first scanned using CT to create a three-dimensional image. Then an electromagnetic tracking system locates the position of the ablation needles in the body (much like a GPS navigation system locating an object in space). This information is then calibrated to information from the CT. “You can now see where your needle is relative to your CT image,” Shechter says.