<abstract xmlns="http://www.w3.org/1999/xhtml">Aim: The aim of the study was to compare several methods of dose prescription, the mean dose, the median dose, the effective dose and the generalized Equivalent Uniform Dose (gEUD).Background: The dose distribution in the planning target volume is never fully homogenous. Depending on the dose prescription method for the same prescribed dose different biologically equivalent doses are delivered. The latest ICRU Report 83 proposes to prescribe the dose to the median dose in the PTV. Several other methods are also in common use. It is important to know what are differences of doses actually delivered depending on the dose prescription method.Materials and methods: The study was performed for three groups of patients treated radically with external beams in Brzozow, over the 2012-2013 period. The groups were of patients with breast, lung and prostate cancer. There were 10 patients in each group. For each patient all metrics, i.e. the mean dose, the median dose, the effective dose and the generalized Equivalent Uniform Dose, were calculated. The influence of the dose homogeneity in the PTV on the results is also evaluated. The gEUD was used as a reference dose prescription method.Results: For all patients, an almost perfect correlation between the median dose and the gEUD was obtained. Worse correlation was obtained between other metrics and the gEUD. The median dose is almost always a little higher than the gEUD, but the ratio of these two values never exceeded 1.013.Conclusion: The median dose seems to be a good and simple method of dose prescription.</abstract>

Aim: The aim of the study was to compare several methods of dose prescription, the mean dose, the median dose, the effective dose and the generalized Equivalent Uniform Dose (gEUD).Background: The dose distribution in the planning target volume is never fully homogenous. Depending on the dose prescription method for the same prescribed dose different biologically equivalent doses are delivered. The latest ICRU Report 83 proposes to prescribe the dose to the median dose in the PTV. Several other methods are also in common use. It is important to know what are differences of doses actually delivered depending on the dose prescription method.Materials and methods: The study was performed for three groups of patients treated radically with external beams in Brzozow, over the 2012-2013 period. The groups were of patients with breast, lung and prostate cancer. There were 10 patients in each group. For each patient all metrics, i.e. the mean dose, the median dose, the effective dose and the generalized Equivalent Uniform Dose, were calculated. The influence of the dose homogeneity in the PTV on the results is also evaluated. The gEUD was used as a reference dose prescription method.Results: For all patients, an almost perfect correlation between the median dose and the gEUD was obtained. Worse correlation was obtained between other metrics and the gEUD. The median dose is almost always a little higher than the gEUD, but the ratio of these two values never exceeded 1.013.Conclusion: The median dose seems to be a good and simple method of dose prescription.

Toward a better prescription method for external radiotherapy

Szpital Wojewodzki im. Sw. Lukasza, Tarnow,

Medical Physics Department, Cancer Center-Institute of Oncology, Warsaw,

Polish Journal of Medical Physics and Engineering

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Toward a better prescription method for external radiotherapy"}

Aim: The aim of the study was to compare several methods of dose prescription, the mean dose, the median dose, the effective dose and the generalized...

Toward a better prescription method for external radiotherapy

Publié en ligne: 30 mars 2017

Pages: 3 - 7

Reçu: 13 févr. 2017

Accepté: 03 mars 2017

DOI: https://doi.org/10.1515/pjmpe-2017-0002

Mots clés
radiotherapy, dose, equivalent uniform dose

© 2017 Polish Society of Medical Physics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Toward a better prescription method for external radiotherapy

Publié en ligne: 30 mars 2017

Pages: 3 - 7

Reçu: 13 févr. 2017

Accepté: 03 mars 2017

DOI: https://doi.org/10.1515/pjmpe-2017-0002

Mots clésradiotherapy, dose, equivalent uniform dose

© 2017 Polish Society of Medical Physics

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Mots clés
radiotherapy, dose, equivalent uniform dose