Focused radiosurgery offers more precision and less toxicity

UAB is in its 15th year of stereotactic radiosurgery, and our experience demonstrates focused radiation may be helpful for cancers in the spine, lung, liver, and pancreas as well as for cranial tumors,” says UAB neurosurgeon and Gamma Knife Medical Director Barton L. Guthrie, MD. UAB radiation oncologist John B. Fiveash, MD, notes, “We are shortening treatments and dramatically advancing the accuracy of radiation delivery.”

The Gamma Knife, the most commonly used instrument to deliver cranial stereotactic radiosurgery, “is as effective as open surgery for local control of metastases from melanoma, lung cancer, and breast cancer,” Guthrie says. After a 10-year partnership with HealthSouth, UAB is now the sole owner of Alabama’s only Gamma Knife, which is located at UAB Highlands in Birmingham. Tumors (metastases, meningioma, acoustic, pituitary, and others) make up 75% of the Gamma Knife’s caseload, but the device also benefits individuals with arteriovenous malformations and trigeminal neuralgia. “It also is an effective tool used in conjunction with standard surgery. Gamma Knife follow-up enhances surgical management of lesions greater than 3 cm and preserves normal brain tissue,” Guthrie says.

Stereotactic Body Radiation
Body radiosurgery delivers high radiation doses to small target regions in the spine, lungs, liver, or other areas using continuous beams in a 360º arc. Large radiation doses are administered over shorter periods — 3 to 5 days instead of several weeks for standard radiation therapy. Precision mapping of lesions allows closer margins and minimizes radiation to normal, healthy tissue.

Stereotactic body radiation therapy (SBRT) requires two precision strategies, says Fiveash. “We immobilize the patient’s body with a vacuum base cushion that conforms to the patient and provides reliable positioning and then pinpoint the target position with a modified linear accelerator (tomotherapy) that scans lesions with computerized tomography. Scanning frequently allows us to detect patient movement and reposition appropriately,” he says. Respiration gating technology on UAB’s other linear accelerators further compensates for movement to pinpoint mobile targets.

“SBRT is best suited for primary or some secondary tumors in the liver, lungs, and spine, but other sites, including the pancreas and prostate, are being evaluated in clinical trials,” he says. Fiveash and Guthrie currently are conducting a clinical trial using tomotherapy for single-fraction spine treatments.

“This technology gives patients a significant advantage. The lungs and liver are far more tolerant of standard radiation therapy than the brain, and focused radiosurgery in these organs is less toxic,” says Guthrie. “Radiotherapy allows patients to return to normal activities or initiate additional treatments, such as chemotherapy, much sooner,” says Fiveash.

Guthrie and Fiveash will participate in national clinical trials investigating 3-day tomotherapy treatment for lung and liver cancer and assessing efficacy of chemotherapy plus stereotactic treatments in decreasing lung tumors’ spread.

Fiveash foresees UAB’s comprehensive body radiosurgery program establishing a paradigm in which surgeons and oncologists synergistically assess patients for surgery and radiosurgery in an actively integrated protocol.

For more information:
Dr. Barton Guthrie
Dr. John Fiveash
1.800.UAB.MIST
mist@uabmc.edu