Peter Campbell, 65, was struggling to find the words to communicate. When his wife asked what his name was and where he lived, he couldn’t think of the answers. Following a CT scan of his brain, he learned that an aggressive type of brain tumor was hindering his speech and language functions. The tumor was removed surgically, and as is standard for treating this type of brain tumor, Campbell began a seven-week course of radiotherapy that is targeting the area where the lesion was removed, in order to kill any cancer cells that might have been left behind.

In his particular case, the daily treatments are taking two minutes to complete rather than the 20 minutes that would have been required using the previous generation of technology. Doctors at the Space Coast Cancer Center in Titusville, Florida are using RapidArc(TM) radiotherapy technology from Varian Medical System (NYSE: VAR). This fast and highly-accurate approach enables doctors to deliver image-guided radiotherapy that precisely conforms to a targeted area two to eight times faster than was previously possible.

“Before my brain tumor was discovered, I could tell that my communication skills were going down fast,” said Campbell, a former educator who has held several public and private administrative positions. “I’m usually very good at crossword puzzles, but suddenly I couldn’t think of a single word to answer the clues. At a party, I had to smile and nod my head because I couldn’t understand what my friends were telling me. This was scary. Thankfully, my speech abilities returned to normal after surgery, and since then, the RapidArc treatments have been as simple as could be.”

Campbell’s radiotherapy began in May and will continue through July. Each weekday, after he’s positioned on a treatment table, a machine equipped with RapidArc delivers his daily treatment in about two minutes. “I don’t feel any discomfort during a session, and after I’m through, I’m able to sit right up and walk out of the center,” he said.

“RapidArc was the best choice for Peter because it is much more precise than alternative treatment methods,” said Cindy Bryant, MD, a radiation oncologist at Space Coast. “The RapidArc plan conformed very closely to the part of his brain where his tumor had been, allowing us to avoid the optic nerves and other important sensitive tissues. But if there’s even a little movement during a treatment, our ability to be this accurate can be affected. That’s why RapidArc is so valuable to us–the treatments are over before a patient has had much time to move.”

Dr. Bryant added, “This is an especially aggressive kind of brain tumor, so we’ll of course be watching very closely how Peter’s doing. RapidArc radiotherapy is an important component of his overall treatment.”

About Space Coast Cancer Center (SCCC)

Serving the residents of Brevard County since 1983, SCCC, an affiliate of the H. Lee Moffitt Cancer Center and Research Institute, is a comprehensive oncology practice serving the residents of Brevard County, Florida. SCCC physicians offer a full range of diagnostic laboratory studies and comprehensive outpatient chemotherapy, radiation therapy, biologic therapy, and immune therapy infusion services. The practice also participates in onside clinical trials, collaborating with the H. Lee Moffitt Cancer Center, Shands Cancer Center, and the National Cancer Institute.

About Varian Medical Systems

Varian Medical Systems, Inc., of Palo Alto, California, is the world’s leading manufacturer of medical devices and software for treating cancer and other medical conditions with radiotherapy, radiosurgery, proton therapy, and brachytherapy. The company supplies informatics software for managing comprehensive cancer clinics, radiotherapy centers and medical oncology practices. Varian is a premier supplier of tubes and digital detectors for X-ray imaging in medical, scientific, and industrial applications and also supplies X-ray imaging products for cargo screening and industrial inspection. Varian Medical Systems employs approximately 5,100 people who are located at manufacturing sites in North America, China, and Europe and in its 79 offices and facilities around the world.

Source: Varian Medical Systems, Inc

Gliomas are among the most common and most malignant brain tumors. These tumors infiltrate normal brain tissue and grow very rapidly. As a result, surgery can never completely remove the tumor. Now, the neurosurgeons Dr. Darko S. Markovic (Helios Klinikum Berlin-Buch) and Dr. Michael Synowitz (Charite) as well as Dr. Rainer Glass and Professor Helmut Kettenmann (both Max Delbrück Center for Molecular Medicine, MDC, Berlin-Buch), have been able to show that glioma cells exploit microglia, the immune cells of the brain, for their expansion (PNAS Early Edition)*.

Microglial cells are the immune cells of the brain/central nervous system. They constantly screen the brain environment. On their surface they use sensors to detect changes in their environment due to brain damage or infections. An important family of these sensors are Toll-like receptors (TLR).

However, microglia do not attack glioma cells. On the contrary: they support the growth of the tumor and, thus, make the disease worse. Together with researchers in Warsaw, Poland, Amsterdam, The Netherlands, and Bethesda, USA, the researchers in Berlin have been able to show how the immune cells promote the tumor growth.

Microglial cells are attracted toward the glioma cells and gather in and around the tumor in large numbers. Interestingly, gliomas consist of up to 30 per cent of microglia, especially at the tumor edge.

Gliomas release certain enzymes, metalloproteases, which digest the extracellular matrix, and also dissolve the ties between cells. However, the metalloproteases are produced and released as inactive precursor protein which need to be cleaved to be activated. This cleavage is accomplished by another enzyme, which is produced by the microglial cells.

This enzyme is anchored in the membrane and was therefore named membrane type 1 metalloprotease (MT1-MMP). MT1-MMP activates the metalloproteases which clear the way for the glioma cells and allows them to infiltrate normal brain tissue and expand very rapidly.

Normally, microglial cells do not produce MT1-MMP. However, the glioma cells manipulate the microglial cells by stimulating microglial TLR which trigger the expression of MT1-MMP.

The researchers could confirm their data from petri dish in mice. “Those mice, in which we had knocked out the MT1-MMP gene or a crucial gene for TLR signalling, did attract fewer microglial cells and the tumor grew much more slowly”, explains Professor Kettenmann.

They could also demonstrate that MT1-MMP was present in tissue from glioma patients. Remarkably, the gliomas with high level of microglial MT1-MMP were also more aggressive. Moreover microglial cells were more abundant in tissue sample from the tumor edge as compared to the center of the tumor.

Glioma cells themselves do not produce MT1-MMP. However, when the researchers experimentally over expressed MT1-MMP in glioma cells, they died.

The researchers hope, that interfering with TLR receptors or their intracellular pathways might reduce the rapid expansion of glioma cells. Professor Kettenmann: “Microglia are a new target for glioma researchers.”

* Gliomas induce and exploit microglial MT1-MMP expression for tumor expansion

D. S. Markovica,b, K. Vinnakotaa, S. Chirasania, M. Synowitza,c, H. Ragueta, K. Stocka, M. Sliwad, S. Lehmanne, R. Ka¨ linf,N. van Rooijeng, K. Holmbeckh, F. L. Heppnerf, J. Kiwitb, V. Matyasha, S. Lehnardte, B. Kaminskad, R. Glassa,1,2, and H. Kettenmanna,1

aCellular Neuroscience, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany;
bDepartment of Neurosurgery, Helios Clinics, 13125 Berlin, Germany;
cDepartments of Neurosurgery and fNeuropathology and eCecilie Vogt Clinic for Neurology, Charite - Universitätsmedizin Berlin, 13353 Berlin, Germany;
dLaboratory of Transcription Regulation, Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland;
gDepartment of Molecular Cell Biology, Faculty of Medicine, Vrije Universiteit, VU University Medical Center, 1081 BT Amsterdam, The Netherlands; and
hCraniofacial Skeletal Diseases Branch, Matrix Metalloproteinase Unit, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892

Source:
Barbara Bachtler

Helmholtz Association of German Research Centres

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