SRP6 (02)

Embargoed until 00.01 GMT Wednesday 23 October 2002

Phantoms give a clearer picture of radiation effects

Maria Zankl of the Institute of Radiation Protection in Neuherberg, Germany, speaking at The Society for Radiological Protection's Internal Dosimetry conference at the British Library today (23/10/02), describes how she and her colleagues are using voxel phantoms to help them understand how different organs are affected by the damaging energies of a radioactive material that has been taken up.

"When a radioactive substance gets inside you, it distributes throughout the body, into bones and organs, and these body sites themselves then become "radioactive sources", Zankl explains. "These internal radiation sources can cause tissue damage and serious health problems, such as radiation sickness and cancer, depending on how much radioactive material was taken up."

Until now, scientists have only been able to estimate very roughly how much of the energy from the radioactive material that is released in the "source organs" is absorbed by these organs themselves, and how much reaches other organs nearby and is absorbed there. This provides values of "organ doses" given that the spread of the radioactive material around the body is already known. These values allow health effects to be predicted but they cannot be measured directly so schematic models of the human body have been used to estimate the energy absorptions.

Zankl and her colleagues have recently assessed the use of body images (recorded with computerised tomography (CT) and magnetic resonance imaging (MRI)) of real people used to create far more realistic body models - "voxel phantoms". These virtual apparitions provide a much clearer picture of the radioactive energy released and absorbed by the internal organs. "We have quantified how large the dose in different organs is, depending on the amount of radioactive material accumulated in the single source organs," explains Zankl. "The new voxel phantoms are a clear improvement over previous ones, since they have a very realistic internal anatomy," she adds, "and the organ distances are exactly the same as in a real person."

Zankl revealed to the meeting that on the basis of her team's results the International Commission on Radiological Protection (ICRP) will use voxel models for future dose calculations.

Notes for editors
1. This release is based on Dr Zankl's paper, 'The development of voxel phantoms for use in internal dosimetry' which will be presented at 2:40pm on 23rd October 2002 at The Society for Radiological Protection's  one-day  meeting, 'Internal Dosimetry'  to be held at the British Library London.

2. Accredited journalists are welcome to free registration to attend this meeting. The Institute of Physics' Press Office is handling media arrangements for this meeting, please contact Dianne Stilwell at the Institute Tel: +44 (0)20 7470 4875, Fax: +44 (0)20 7470 4848, E-mail: dianne.stilwell@iop.org if you would like to attend. The meeting programme and further information can be found on the Society for Radiological Protection's Web page http://www.srp-uk.org/eventoct02.html

3. Further information on this paper is available from Dr Zankl who will be contactable on tel +49 89 3187 2792, email zankl@gsf.de She will not be available on the day of the meeting nor the morning of the next day until noon. She would prefer to be contacted by email in any case.

4. During the meeting itself please contact the Society's media representative, Pauline Powell. She will be available from 09.30 to 16.00 hours on Wednesday 23 October 2002. To contact her during that time, call the reception desk on tel: +44 (0)207 412 7050.

5. The Society for Radiological Protection was founded in 1963, the Society now has nearly 2000 members, including International members, and is the leading Scientific Society in the UK for all who are professionally concerned with safety aspects of uses of ionising and non-ionising radiation in education, central and local government, industry, medicine and research.

The Society has the following objectives :-

• to promote and advance the science of radiological protection and allied fields;
• to promote, advance and disseminate to the public advantage, knowledge of radiological protection and allied fields;
• to encourage, support, promote and advance education and learning in radiological protection and allied fields;
• to promote and encourage high scientific, educational, regulatory and professional standards in radiological protection and allied fields.

top of page