Important to review advances in diagnosis and treatment during Brain Tumor Awareness Week

Friday, May 02, 2003

JACKSONVILLE, Fla., May 2, 2003 — Florida Gov. Jeb Bush and Jacksonville Mayor John Delaney declared May 4-10 Brain Tumor Awareness Week in Florida and Jacksonville respectively. Two-thirds of Floridians diagnosed with malignant brain and central nervous system cancers die from the disease (according to the latest data from the Florida Cancer Data System). But Dr. Kurt Jaeckle, a neuro-oncologist who heads the Neuro-oncology Program at Mayo Clinic in Jacksonville, says recent advances in diagnosing and treating brain tumors should be cause for hope. "It isn't a death sentence for everybody," he says. "It may seem that progress is taking place slowly, but it is taking place."

Jaeckle says advances in imaging techniques have had a great impact on physicians' ability to diagnose and plan treatment for brain tumors. "Modern imaging techniques allow us to define where the tumor is located and precisely determine if it's growing or shrinking," he says. "And these images can also be merged with the radiation treatment planning — it's called co-registration — so that physicians can more accurately plan treatment from those images."

In addition, images that are generated by diagnostic machines, MRI in particular, can now be used during surgery to help neurosurgeons perform tissue biopsies and remove tumors. "Currently surgical removal of brain tumors is the most important first step in successful treatment," says Dr. Robert Wharen, chair of the Department of Neurosurgery at Mayo Clinic in Jacksonville. "The more tumor that is removed the better chance radiation, chemotherapy, and gene therapy have of being successful after tumor removal. This ultimately results in better outcomes for patients."

Wharen says fortunately most tumors can be substantially or totally removed by experienced neurosurgeons using new imaging and surgical guidance technologies. Neurosurgeons at Mayo Clinic in Jacksonville use guidance systems in the operating room that give them the ability to know the exact the location of the brain tumor at all times as well as the location of important brain functions such as speech and strength. This guidance improves the safety and accuracy of surgery more than ever before.

Advances in imaging techniques, including magnetic resonance spectroscopy (MRS) and positron emission tomography (PET) have also enabled physicians to distinguish between growing tumor and growing areas of dead tissue, which can look similar on a regular MRI scan. "In patients who have already received radiation treatment and chemotherapy, these techniques help us decide whether the abnormality is primarily tumor or dead tumor tissue," Jaeckle says. "Dead tissue also may appear to grow as it evolves, so it is often hard to distinguish between the two. This distinction is important in planning further treatment, as you do not want to give more radiation or chemotherapy if the problem is primarily dead tumor tissue. But you may want to change the treatment if the abnormality is growing tumor."

Jaeckle says there has been an explosion of techniques to look at the function of the tumor and not just its physical characteristics. "Magnetic resonance spectroscopy allows us to see a selective profile of the chemicals that are inside the tumor cells," he says, "which change in specific and recognizable patterns as the tumor grows or responds to treatment."

Aided by advanced imaging equipment, radiation oncologists are performing new techniques such as conformal field and stereotactic radiotherapy. This allows more precise delivery of the radiation to the tumor while limiting the amount of radiation as much as possible to normal brain tissues. IMRT, which modulates the amount of radiation directed at the tumor so that some areas receive more radiation and some less, is another technique developed to make radiation therapy safer and more effective.

Medical treatment of brain tumors in Mayo's Neuro-oncology Program has focused on gliomas, the most common type of brain tumor. Investigators are looking at the synergy that occurs between radiation and chemotherapy to try to define better ways to treat tumors. There is also an emphasis on novel, targeted therapies, which Jaeckle describes as a departure from prior radiation and chemotherapy regimens. "These are based on molecular biologic mechanisms that are known to be overactive in cancer cells," he says. "In other words, these targeted therapies often block important switches that the cancer cells use to keep dividing and growing." There are five targeted therapies in clinical trials underway at Mayo using molecules that interrupt or bind to proteins that are critical in the pathways to growth and uncontrolled division of tumor cells.

These research efforts and others at Mayo Clinic in Jacksonville are performed in collaboration with colleagues at Mayo Clinics in Rochester, Minn., and Scottsdale, Ariz., as well as with other researchers who are members of the North Central Cancer Treatment Group, a major cancer clinical cooperative group supported by the National Cancer Institute (NCI).

With the extension last year by the NCI of its Comprehensive Cancer Center designation to include all three Mayo Clinics, the Jacksonville facility has launched its own freestanding basic cancer research program. Discoveries from these laboratories will add to the collective understanding of cancer and lead to improved treatments for this feared disease.

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