The latest radiosurgical technology
Dr Bill Bice, Chief Medical Physicist explains the
groundbreaking technology that will provide patients the best
chance to beat their cancer.
Both the Trilogy System and CyberKnife are
incredibly innovative pieces of equipment.
Over the last 20 years all new technology has
concentrated on how to better deliver doses of radiation to a
tumour whilst sparing as much normal tissue as possible. These two
systems represent the very latest in the development of
radiotherapy and radiosurgical treatment.
Let me give you a short history of this
development to put things in context: 20 years ago only the most
basic beam shaping was done: rectangular beams of radiation were
focused on the patient’s tumour, no matter what shape the tumour
took or what normal tissues surrounded it. Simple, thick metal
blocks came to be used to shield the normal tissues to some degree,
but this was still very rudimentary.
Right: CyberKnife®
Robotic Radiosurgery System
Computers came along and developed to the
point that the dose from the radiation treatments could be viewed
and planned in 3 dimensions inside the patient’s body. This type of
treatment, termed 3DCRT, was the best available until the advent of
Intensity Modulated Radiotherapy (IMRT). IMRT, which has only
become commercially available in the last ten years, allowed
shaping the dose until it was very conformal to the tumour. With
this increased control and conformity came increased requirement to
deliver the radiation more precisely to the right place in the
body. Enter better imaging, allowing alignment of the radiation
beams right before treatment or even during the treatment. On the
heels of IMRT came IGRT, Image
Guided Radiotherapy.
Various forms of image guided technology –
ultrasound, CT and stereoscopy – have been introduced into the
treatment room over the last 
five years allowing for a more and more
accurate delivery of the radiation. Recently we have even been able
to incorporate and correct for the effects of patient motion (like
breathing) during the
delivery of the radiation.
All of these developments have enabled us to
use much smaller, better controlled radiation fields to be
delivered more accurately to the tumour-sparing healthy tissue.In
the end this allows us to give higher doses of radiation whilst
minimising complications and provides us a better opportunity
to cure the patient.
Above:
Trilogy® System with RapidArc™
The Trilogy System with on board imaging, portal vision and
conebeam CT scan which is taken with a rotating movement to give
IGRT, gives us the most detailed image of the patient and the
tumour to be treated.
The Trilogy system also employs RapidArc, a
technology that allows us to deliver IMRT at much greater speeds –
shortening patient treatments. This improves accuracy and the
general comfort of the patient.
CyberKnife uses many, many small beams to
build up an IMRT-like distribution. IGRT is achieved using
stereotactic localisation from two fixed X-ray tubes which monitor
the patient’s position during the robotically delivered radiation
fields.
One advantage that CyberKnife has is the
ability to deliver the radiation from almost any angle without
moving the patient. CyberKnife boasts sub-millimetre precision on
phantoms with only a slight decrease in accuracy for actual patient
treatments. The CyberKnife and the Trilogy both have the ability to
gate treatment, tracking the tumour as it moves in the body –
during breathing for example.
Essentially what we have with the Trilogy
System and CyberKnife are two complementary cutting-edge
modalities. With this equipment we can deliver every type of
external beam X-ray treatment that the clinician would ever want to
deliver.
It is a great position to be in.
I am very excited about being able to give our
patients the very best treatment available and, more importantly,
giving them the best chance to beat their cancer.
Dr Bill Bice, Chief Medical Physicist at The London
Clinic Cancer Centre
For any queries regarding
CyberKnife® or Trilogy treatment at The London Clinic,
please contact at info@thelondonclinic.co.uk or
call: 020 3219 3218
| More information about CyberKnife® and
radiosurgery |
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- Innovation! See the
Cyberknife® in action
- Trilogy® Systems with
RapidArc™
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