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Radiation Therapy with standard x-rays and Proton therapy for
medulloblastoma
For
certain tumors of the brain, radiation is given to the back of the brain
(posterior fossa). With standard radiation there is incidental dose given
to healthy brain tissue surrounding the tumor. An example of this is the
cochlea, the organ in the middle ear that is responsible for bringing sound
into the ear through the nerves. Injury to the cochlea can have the potential
long term effect of hearing loss. One benefit of proton therapy is the ability
to shape the radiation so that less dose is delivered to the cochlea. Clinical
studies are
under way to determine the long term affects in children.
Radiation Therapy with standard x-rays to the spine
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Figure 2 |
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Figure 2 and Figure 3 show radiation treament plans for treatment to the spine.
Figure 1 shows the dose distributions of conventional x-rays. Figure 2 shows
the dose distributions using proton therapy. The color key on the right gives
the amount of dose delivered.
The goal of radiation therapy is to deliver radiation to the specific areas,
such as the spine as seen in Figure 2 , while preserving the surrounding
normal healthy tissue. The image shows the dose distribution affecting the
spine (the intended target) and encompassing the heart...an area that could
lead to scarring and dysfunction in children.
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Figure 3 |
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Proton Therapy to the Spine
In Figure 3, proton therapy provides much less radiation given
to the heart, while providing targeted therapy to the spine. Clinical
studies are underway to determine if this results in less cardiac and
pulmonary complications of radiation in children.
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