Monday, January 17, 2011

Proton Radiation Treatment

Proton Radiation Treatment


Forming ions (atoms with an electric charge) in diseased tissue allows physicians to either kill cancerous cells completely, or to alter the genetic code to limit tumor growth. Photon radiation using gamma or x-rays remains common---but particle radiation, specifically proton radiotherapy, assumes a larger role in cancer treatment centers and hospitals of the future.


The Facts


According to the American Cancer Society (ACS), the protons in the particle beam achieve end results: they damage cells at the destination, leaving healthier cells in their path relatively unharmed. Thus, radiation oncologists may deliver stronger beams to the diseased mass and cause fewer side effects in the surrounding tissue. This relatively new technology remains under scrutiny, particularly as proton radiation therapy exposes patients to higher doses of neutrons, which may cause subsequent cancers.


Preparation


Radiation therapy takes several weeks beginning with a simulation session, in which the therapist determines where to aim the radiation beam by looking at x-rays or CT scans. To ensure proper targeting, patients need to lie still. Therapists may employ specialized molds and casts to immobilize specific body parts, and may pinpoint the target area on the patient's skin with ink. The ACS says oncologists then determine the strength of the radiation, number of treatments, and administer them.


Time Frame


For radiological procedures, including proton therapy, treatment duration depends on many factors, including the patient's overall health, the type of the cancer, location, size of the tumor, and more. Oncologists generally administer treatment five days per week for one to two months, but may allow a break to give the body time to heal. Other therapies require hyperfractionated treatment, in which the patient receives more than one dose per day. The ACS states that positioning the patient properly takes the most time (15-30 minutes per session) and that the actual radiation dosing only takes a few minutes.


Warning


The Midwest Proton Radiotherapy Institute (MPRI) cites fatigue, skin irritation and hair loss as minor side effects for proton radiation patients. However, Doctors David J. Brenner and Eric J. Hall of Columbia University Medical Center cite equal risks of secondary cancer due to neutron exposure from proton therapy and other radiological treatments. The ASC cites other concerns based on where the tumor lives---digestive problems may result in the case of stomach cancer for example.


Future


Because the proton beam goes directly to the tumor and from multiple directions, proton therapy requires an expensive, computerized, proton accelerator called a cyclotron or synchrotron to focus on the diseased tissue. Only a few treatment centers and hospitals use proton radiation today, though Columbia University speculates worldwide institutions will incorporate the technology at a rapid rate in the future.

Tags: proton radiation, proton therapy, centers hospitals, Columbia University, diseased tissue, Proton Radiation, Proton Radiation Treatment