Measuring dose Ionisation chamber

Ionization Chambers Thimble chambers 600cc chamber

Determination of Absorbed dose Absorbed dose to water Corrections for Influence quantities

Corrections Accurate dosimetry requires many small corrections E.G. Temperature/Pressure –Ionisation charge collected depends on amount of air in chamber –Correct by Other corrections for chamber characteristics –Recombination, polarity effects Complex business, keeps us in work!

Medical Physics as a career

Training Minimum honours degree in physics Training process follows –Employed as “registrar” in a radiotherapy department Masters or Doctorate will be completed during this time Five years hospital experience –After five years, accreditation exams Three hour written exam Half day practical exam Oral exam Most recover, with counselling!

Some of the staff

Physicist numbers There are 268 ROMPs in Australia employed at ~50 sites There is a mild shortage of ROMPs –14% positions unfilled in Australia –Many vacancies are filled from overseas Very international flavour to most departments Peter MacCallum Cancer Centre is one of Australia’s largest employers of ROMPs with 18 staff, including 3 registrars.

Other numbers!

Others states do better … NSW has been much more effective at setting conditions We want what they’ve got!

Roles within Peter Mac Radiation protection –Targeting lowest possible occupational doses Dosimetry –Checking output against national laboratory standards Brachytherapy –Clinical work treating patients using radioactive sources Teaching/lecturing –Medical registrars Quality assurance –After hours work checking machine outputs and alignments Research –Many clinical projects trialling new approaches to treatment Development towards improved treatment –Application of new technology

Physicists at work

Working conditions:

So, what else do we do? About 50% (+/-30%!) of our time is unscheduled Most work is project based and open ended Most physicists have a specialty and pursue a project in that area My interest is in setup correction –Study of position accuracy for patients on treatment –New imaging tools have become available –New treatment techniques