Page 69 - 2014 Printable Abstract Book
P. 69
quality electrons. Using this technology, we determined the toxicity and dose response relationship
between LWFAs VHEEs (100-150MeV) and tumour cell kill. The clonogenicity was determined of two lung
cancer cell lines following 0, 1, 2 and 4 Gy irradiation, with either LWFAs VHEEs, or X-ray photons delivered
by an Xrad-225 cell irradiation cabinet. Furthermore we have compared the magnitude and dynamics of
DNA double stranded break formation and repair following irradiation with LWFA VHEE with that
produced by X-ray photons, using γH2AX as a molecular marker for DNA double stranded breaks. One of
the properties of LWFA electron beams is the emission of bremsstrahlung gamma radiation as the beam
propagates through water. The relative energy of these components varies with depth through a water
medium and therefore the nature and the energy of the radiation experienced by the biological target at
increasing depths changes with distance from the point of penetration. To understand the radiobiological
effect on tumour cells as the composition and energy of the radiation changes, we have measured the
clonogenic capacity of our lung cancer cell lines, irradiated at different positions and depths from the
radiation source, in a water bath along the beam line. The significance of these findings for clinical
radiotherapy will be discussed.
S17 SPECIAL JOINT RRS-HPS SYMPOSIUM: RADIATION HEALTH EFFECTS IN CHILDREN: ISSUES AND
CHALLENGES FROM RADIATION PROTECTION TO PEDIATRIC RADIATION ONCOLOGY
Childhood cancer patients greatly benefit from the diagnostic and therapeutic use of ionizing radiation
but may suffer later health effects from their treatments. This special joint HPS-RRS symposium will focus
on a broad contemporary perspective of the risks, benefits and problems found in the medical applications
of radiation in children.
(S1701) Justification, optimization and communication in pediatric CT imaging: review of recent
improvements and persistent challenges. Jerrold Bushberg, University of California, Davis, Davis, CA
It would be difficult to overestimate the value and impact computed tomography (CT) has made to the
diagnosis and treatment injuries and illnesses since its clinical début in 1971. The use and capability of
medical imaging has increased rapidly worldwide during the past decade, and the rise in the use of
pediatric CT was one of the main contributors. On a global scale the use of CT accounts for about 34% of
the collective dose and is a major source of medical radiation exposure in children. While the use of x-rays
for medical imaging helps millions of patients worldwide, inappropriate use may result in unnecessary
and preventable radiation risks. A balanced approach is needed that both maximizes health benefits and
minimizes risk. CT remains a powerful tool in the diagnosis of pediatric illness and there is little doubt that
the benefits of its use vastly outweigh potential risks when it is appropriately prescribed and properly
performed (i.e. justified and optimized). During the last few years, advocacy campaigns to promote
appropriate use of radiation in pediatric imaging have been conducted by several organizations. The
Image Gently Campaign, created by the Alliance for Radiation Safety in Pediatric Imaging
(http://www.pedrad.org/associations/5364/ig/), is likely the most widely recognized educational and
awareness campaign. Among the many attributes of this program is its comprehensive web site that
allows users to access information where the scope and readability of the content is tailored to the
intended audience (e.g., parents, technologists, medical physicists, radiologist and referring physicians).
Although doses from pediatric CT scans have decreased, multiple opportunities to further reduce patient
67 | P a g e
between LWFAs VHEEs (100-150MeV) and tumour cell kill. The clonogenicity was determined of two lung
cancer cell lines following 0, 1, 2 and 4 Gy irradiation, with either LWFAs VHEEs, or X-ray photons delivered
by an Xrad-225 cell irradiation cabinet. Furthermore we have compared the magnitude and dynamics of
DNA double stranded break formation and repair following irradiation with LWFA VHEE with that
produced by X-ray photons, using γH2AX as a molecular marker for DNA double stranded breaks. One of
the properties of LWFA electron beams is the emission of bremsstrahlung gamma radiation as the beam
propagates through water. The relative energy of these components varies with depth through a water
medium and therefore the nature and the energy of the radiation experienced by the biological target at
increasing depths changes with distance from the point of penetration. To understand the radiobiological
effect on tumour cells as the composition and energy of the radiation changes, we have measured the
clonogenic capacity of our lung cancer cell lines, irradiated at different positions and depths from the
radiation source, in a water bath along the beam line. The significance of these findings for clinical
radiotherapy will be discussed.
S17 SPECIAL JOINT RRS-HPS SYMPOSIUM: RADIATION HEALTH EFFECTS IN CHILDREN: ISSUES AND
CHALLENGES FROM RADIATION PROTECTION TO PEDIATRIC RADIATION ONCOLOGY
Childhood cancer patients greatly benefit from the diagnostic and therapeutic use of ionizing radiation
but may suffer later health effects from their treatments. This special joint HPS-RRS symposium will focus
on a broad contemporary perspective of the risks, benefits and problems found in the medical applications
of radiation in children.
(S1701) Justification, optimization and communication in pediatric CT imaging: review of recent
improvements and persistent challenges. Jerrold Bushberg, University of California, Davis, Davis, CA
It would be difficult to overestimate the value and impact computed tomography (CT) has made to the
diagnosis and treatment injuries and illnesses since its clinical début in 1971. The use and capability of
medical imaging has increased rapidly worldwide during the past decade, and the rise in the use of
pediatric CT was one of the main contributors. On a global scale the use of CT accounts for about 34% of
the collective dose and is a major source of medical radiation exposure in children. While the use of x-rays
for medical imaging helps millions of patients worldwide, inappropriate use may result in unnecessary
and preventable radiation risks. A balanced approach is needed that both maximizes health benefits and
minimizes risk. CT remains a powerful tool in the diagnosis of pediatric illness and there is little doubt that
the benefits of its use vastly outweigh potential risks when it is appropriately prescribed and properly
performed (i.e. justified and optimized). During the last few years, advocacy campaigns to promote
appropriate use of radiation in pediatric imaging have been conducted by several organizations. The
Image Gently Campaign, created by the Alliance for Radiation Safety in Pediatric Imaging
(http://www.pedrad.org/associations/5364/ig/), is likely the most widely recognized educational and
awareness campaign. Among the many attributes of this program is its comprehensive web site that
allows users to access information where the scope and readability of the content is tailored to the
intended audience (e.g., parents, technologists, medical physicists, radiologist and referring physicians).
Although doses from pediatric CT scans have decreased, multiple opportunities to further reduce patient
67 | P a g e
