http://www.bccancer.bc.ca/ABCCA/NewsCentre/2007/vmat.htm
New technology developed at BC Cancer Agency may revolutionize radiation
therapy delivery

Gordon Wright, a 72 year old retired commercial fisherman diagnosed with
prostate cancer this July, is the first patient in the world treated with
this technology.

“I obviously wanted the best treatment possible,” says Wright, whose first
treatment lasted just over a minute and a half, “and it’s comforting to
know that I’m benefiting from the latest technology while contributing to
research that can help many people in the future.”

The technology, Volumetric Modulated Arc Therapy (VMAT), allows a patient
to receive radiation treatment with a single 360º rotation of the
radiation beam around the body. VMAT involves an innovative method for
manipulating the radiation beams that can be delivered from a standard
linear accelerator (a machine used to give radiation therapy to destroy
cancerous tumours) – a technique that has never been accomplished before.

With conventional radiation therapy, treatment cannot be delivered with a
single rotation of the radiation beam – instead the linear accelerator’s
gantry (the part from which radiation is emitted) is re-positioned
throughout a treatment session to target the tumour from a number of
specific directions.

“VMAT creates a precisely sculpted 3D dose distribution by tailoring the
shape and intensity of the beam from a full 360º around the patient,”
explains Dr. Karl Otto, BC Cancer Agency medical physicist who spearheaded
this technology. “This provides more flexibility in maximizing the dose of
radiation targeting the tumour, while minimizing damage to surrounding
healthy tissue.”