PHILADELPHIA, PA (July 18, 2010) -- A study presented today at the 52nd Annual Meeting of the American Association of Physicists in Medicine (AAPM) shows that children with brain tumors who undergo radiation therapy (the application of X-rays to kill cancerous cells and shrink tumors) may benefit from a technique known as "intensity modulated arc therapy" or IMAT.
This technique relies upon new features on the latest generation of X-ray therapy equipment that allow X-ray sources to be continuously rotated in any direction around a patient during treatment, potentially increasing the number of directions that the beams come from.
The study, which was conducted by medical physicists at St. Jude Children's Hospital in Memphis, TN, compared different treatment strategies including IMAT for nine children treated with radiation therapy for brain tumors. It showed that IMAT could irradiate these tumors effectively while overall reducing the exposure to the surrounding tissue.
"Anything we can do to reduce that dose is obviously better," says St. Jude's Chris Beltran, who is presenting the study today in Philadelphia.
Treating cancer through radiation therapy can be complicated for certain types of tumors that are surrounded by sensitive tissue. Many brain tumors, for instance, are deep inside the skull and may require the X-rays to pass through critical structures -- the eyes, the ears, and parts of the brain itself.
The X-rays have the potential to damage these structures, which can lead to lasting side-effects from the treatment. Sending X-rays through the ear may damage the cochlea and lead to permanent hearing loss. Likewise, exposing the brain's temporal lobes to ionizing X-ray radiation can cause loss of mental acuity.
Because modern equipment for radiation therapy allows the source of X-rays to continuously move around the patient, says Beltran, "It gives you the freedom to choose where the beams come from."
In his study he showed that a treatment plan incorporating IMAT would help spare the sensitive surrounding tissues. Using common measures that relate radiation dosage to tissue damage, he predicts that the IMAT plan would cause less hearing loss and damage to the temporal lobes as compared to other treatment plans.
The presentation "Intensity Modulated Arc Therapy for Pediatric Brain Tumors" by J Gray and C Beltran will be at 3:00 p.m. on Sunday, July 18 in the exhibit hall of the Philadelphia Convention Center.
MORE MEETING INFORMATION
AAPM is the premier organization in medical physics, a broadly-based scientific and professional discipline encompassing physics principles and applications in medicine and biology. Its membership includes medical physicists who specialize in research that develops cutting-edge technologies and board-certified clinical medical physicists who apply these technologies in community hospitals, clinics, and academic medical centers.
The presentations at the AAPM meeting will cover topics ranging from new ways of imaging the human body to the latest clinical developments on treating cancer with high energy X-rays and electrons from accelerators, brachytherapy with radioactive sources, and protons. Many of the talks and posters are focused on patient safety -- tailoring therapy to the specific needs of people undergoing treatment, such as shaping emissions to conform to tumors, or finding ways to image children safely at lower radiation exposures while maintaining good image quality.
Main Meeting Web site:
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Journalists are welcome to attend the conference free of charge. AAPM will grant complimentary registration to any full-time or freelance journalist working on assignment. The Press guidelines are posted at: http://www.
Advanced registration form online: http://www.
Press registration on-site will take place at the AAPM Registration Desk, 200 Level Bridge just outside Hall A-B in the Pennsylvania Convention Center.
Questions about the meeting or requests for interviews, images, or background information should be directed to Jason Bardi (firstname.lastname@example.org, 858-775-4080).
ABOUT MEDICAL PHYSICISTS
If you ever had a mammogram, an ultrasound, an X-ray, CT, MRI or a PET scan, a medical physicist was working behind the scenes to make sure the imaging procedure was as effective as possible. Medical physicists are involved in the development of new imaging techniques, improve existing ones, and assure the safety of radiation used in medical procedures in radiology, radiation oncology and nuclear medicine. They collaborate with radiation oncologists to design cancer treatment plans. They provide routine quality assurance and quality control on radiation equipment and procedures to ensure that cancer patients receive the prescribed dose of radiation to the correct location. They also contribute to the development of physics intensive therapeutic techniques, such as the stereotactic radiosurgery and prostate seed implants for cancer to name a few. The annual AAPM meeting is a great resource, providing guidance to physicists to implement the latest and greatest technology in a community hospital close to you.
The AAPM is a scientific, educational, and professional nonprofit organization whose mission is to advance the science, education and professional practice of medical physics. The Association encourages innovative research and development, helps disseminate scientific and technical information, fosters the education and professional development of medical physicists, and promotes the highest quality medical services for patients. Please visit the Association Web site at http://www.