November 9th: Dose optimisation


World Radiography Day marks the date that Wilhelm Roentgen made the discovery of x-rays in 1895. On November 8th radiographers use this occasion to promote the benefits and dispel common myths about the use of ionising radiation in medicine, both to diagnose and treat disease, and to raise the profile of the profession. As part of these international celebrations, MedRadJclub is hosting a special edition chat, incorporating four articles related to dose optimisation. The chat was moderated by Nick Woznitza.

The frequency of medical imaging that uses ionising radiation has increased in the last decade, which has raised concerns about increasing radiation exposure, both cumulative for individual patients and aggregate across the population. Technological advances in equipment have presented radiographers with fantastic opportunities to optimise dose, however this requires the way that radiographers practice to change with the evolving technology. Traditionally, using analogue (film) systems, overexposure resulted in a non-diagnostic image, but with digital imaging this can be corrected with post processing. The very tools that can help prevent repeated examinations can also result in excessive dose being given and diligent practice is required.

While using the “right dose for the right patient” is also an important issue in radiation therapy, the dose and fractionation are usually pre-prescribed by the radiation oncologist (in some cases advanced practice/consultant radiographers may contribute to dose prescription more directly). However, therapeutic radiographers are involved in the CT simulation and subsequent verification while on treatment. Opportunities exist in both of these areas to optimise imaging dose. The articles selected this month for World Radiography Day include CT dose optimization for paediatric patients in diagnostic imaging,  developing size-based radiotherapy kilovoltage cone beam CT (CBCT) protocols for radiotherapy to the pelvis and an examination of dose-optimizing exposure indexes in digital radiography.

Mothiram et al. Digital radiography exposure indices: A review J Med Radiat Sciences 2014;61:112-18

Rodgerson ALARA and paediatric imaging in radiation therapy: A survey of Canadian paediatric imaging practice Radiography 2014;20:183-88

Al Mahrooqi et al. Pediatric Computed Tomography Dose Optimization Strategies: A Literature Review J Med Radiat Imaging Sciences 2015;46;241-49

Wood et al. Accounting for patient size in the optimization of dose and image quality of pelvis cone beam CT protocols on the Varian OBI system Br J Radiol 2015;88:0150364


T1 = How do you optimise your practice to minimise dose?

T2 = What are barriers to dose optimisation?

T3 = Is it within the radiographers role/scope to optimise dose?

Analytics and transcripts of the chat can be found here (H/T Adam Westerink) and here (H/T @WeGizmos).

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