Potential for non-invasive brain tumor treatment

	Tweet

Duke University engineers have taken a first step toward a minimally invasive treatment of brain tumors by combining chemotherapy with heat administered from the end of a catheter.

The proof-of-concept study demonstrated that it should be technically possible to treat brain tumors without the side effects associated with the traditional approaches of surgery, systemic chemotherapy or radiation.

The bioengineers designed and built an ultrasound catheter that can fit into large blood vessels of the brain and perform two essential functions: provide real-time moving 3-D images and generate localized temperature increases. The researchers envision using this system in conjunction with chemotherapy drugs encased in heat-sensitive microbubbles called liposomes. 

"Physicians would inject drug-carrying liposomes into a patient’s bloodstream, and then insert a catheter via a blood vessel to the site of the brain tumor,” said Carl Herickhoff, fourth-year graduate student at Duke’s Pratt School of Engineering and first author of a paper appearing in the journal Ultrasonic Imaging. “The catheter would use ultrasound to first image the tumor, and then direct a higher-power beam to generate heat at the site, melting the liposome shells and releasing the chemotherapy directly to the tumor.

“The temperature increase would be about four degrees Celsius – enough to melt the liposome, but not enough to damage surrounding tissue,” Herickhoff said. “No one has tried this approach before in the brain.”

The American Cancer Society estimates that more than 21,000 new brain tumor cases were diagnosed in 2008, with more than 13,000 patients dying. This represents about two percent of all cancer deaths.

The researchers said that a minimally invasive approach to treating this cancer would be preferable to the conventional methods, which have drawbacks and side effects of their own.

“Surgery is invasive, and chemotherapy that is injected or taken orally affects the whole body and has difficulty crossing the blood-brain barrier in sufficient concentrations,” Herickhoff said. The blood-brain barrier restricts the passage into the brain of any foreign matter not needed by the neural tissue.

In a series of experiments in animal models and simulated tissues, the researchers demonstrated that they could build a catheter thin enough to be placed in one of the brain’s main blood vessels that was capable of serving the dual purpose of visualization and heating.

“Taken as a whole, the results of these experiments, in particular the clarity of the images and ability to increase temperature with the same catheter, lead us to believe that the ultimate creation of a practical intracranial ultrasound catheter is possible,” said Stephen Smith, director of the Duke University Ultrasound Transducer Group and senior member of the research team. “There are some design issues of the catheter itself that we feel can be overcome with little difficulty.”

Advances in ultrasound technology have made these latest experiments possible, the researchers said, by generating detailed, 3-D moving images in real-time. The Duke laboratory has a long track record of modifying traditional 2-D ultrasound – like that used to image babies in utero – into the more advanced 3-D scans. After inventing the technique in 1991, the team also has shown its utility in developing specialized catheters and endoscopes for real-time imaging of tissues throughout the body.

Much of the liposome research was carried out at Duke by David Needham, professor of mechanical engineering and materials science, and Mark Dewhirst, professor of radiation oncology.

###

The research in Smith’s lab is supported by the National Institutes of Health. Other members of the team, also from Duke, are Edward Light, Kristin Bing, Srinivasan Mukundan, Gerald Grant and Patrick Wolf.

Contact: Richard Merritt

919-660-8414
Duke University

RELATED STORIES:
HIV-positive head and neck cancer patients benefit from radiation therapy   Early morning smokers have increased risk of lung and head and neck cancers   New treatment combination proves safe, effective for head and neck cancer patients   HPV-Positive Tumor Status Indicates Better Survival in Patients with Oropharyngeal Cancer   Combining radiation therapy, chemotherapy safely treats head and neck cancer patients   BNCT, a new-generation radiation treatment, is effective in advanced head and neck cancer   Evidence “increasingly against” phone cancer risk   Gene expression to distinguish metastasizing from non-metastasizing head and neck cancers   Enhanced treatment of brain tumors   Certain head and neck cancer patients benefit from second round of treatment   Brain tumors: New therapy surprisingly successful   Brain metastases hijack neuron-supporting cells to resist chemotherapy   Some brain tumors mimic the genetic program of germline cells   Novel Suicide Gene Therapy Used to Treat Malignant Brain Tumors   Blood Pressure Compound May Benefit Brain Tumor Patients   Researchers Pinpoint Origin of Deadly Brain Tumor   IMRT improves outcomes in patients with extranodal lymphoma of the head and neck   Signaling System Found that Halts the Growth of a Childhood Brain Cancer   Tobacco and alcohol use independently increase risk of head and neck cancer   Venom protein may lead to brain cancer cure   Genetics of children’s brain tumour unlocked   First animal model that mimics human head and neck cancer

Comments

[ + Post Your Own ]

Now you're in the public comment zone. What follows is not Armenian Medical Network's stuff; it comes from other people and we don't vouch for it. A reminder: By using this Web site you agree to accept our Terms of Service. Click here to read the Rules of Engagement.

There are no comments for this entry yet. [ + Comment here + ]