Optimization of Medical Accelerators

OMA Fellows join forces to improve cancer treatment beam diagnostics

Last month OMA Fellows Jacinta Yap
(University of Liverpool) and our Early Stage Researcher Navrit Bal (ASI),
along with QUASAR members Roland
Schnuerer and Hao Zhang from the Cockcroft
Institute visited the Clatterbridge Cancer
Centre (CCC), UK to meet with the Head of
the Douglas Cyclotron, Dr Andrzej Kacperek.
The CCC is treating patients with ocular
tumours since 1989.

Building on already existing collaboration with
CCC, the addition of ASI (Amsterdam
Scientific Instruments) to this group
represents another link between partners
within our OMA network. This meeting marks
the first of multiple intended visits, to carry
out joint measurements with the 60 MeV
proton therapy beamline.
Discussion during the visit included the
current status of GEANT4 beamline
simulations and the VELO setup. Further, an
initial schedule to take measurements with
VELO & Medipix3 with the CCC clinical beam
was proposed. As both systems are designed
by the same team at CERN, this example
shows how both devices are applicable to be
transferred from a fundamental research
environment to a clinical facility.

Navrit’s project involves characterization and improvement of the Medipix3 chip, the
readout and control software and a variety of
applications using the chip. Typically x-rays
and electrons are used with less than 0.1% of
the energy than the protons in CCC and
significantly lower flux which presents some
The Medipix3 chip is meant for very different
applications. Thus, it enables direct beam
profile measurements complementary to
VELO measuring the beam halo. Additionally,
it may be possible to measure the Bragg peak
of the beam with the same equipment at
micro meter resolution instead of mm or cm.
These types of measurements have not been
attempted before with Medipix3 detectors. If
they work as expected, this would be a jump
in the level of quality assurance for the CCC.
The group is looking forward to first
measurements which are estimated to be
performed between thisspring and summer.