- Email: [email protected]
eLQ : A biologically-equivalent dose calculator available on iPhone, Android, and the web
Practical Radiation Oncology (2011) 1, 212–213
www.practicalradonc.org
Correspondence
eLQ : A biologically-equivalent dose calculator available on iPhone, Android, and the web
tool fitting in a lab coat pocket; and (2) to sensitize young radiation oncologists to radiobiology and the influence of fractionation. The calculator was created using Apple's Xcode Developer Tool Technology with the PhoneGap open source framework and jQtouch. It is the first free calculator that is academically supported. Inside the application, the user is invited to choose an organ at risk or a predefined α/β value, and enter total prescribed dose, initial dose per fraction, and new dose per fraction. The equivalent dose is then calculated. Alerts based on linear-quadratic model limitations and dose constraints for each organ are activated, should any parameters be out of the defined boundaries. The linear-quadratic model is used to predict biological response to radiation when fractionation is altered.2-5 Each organ is characterized by 2 parameters: α represents the cell kill per Gy of the initial linear component and β the cell kill per Gy of the quadratic component of the survival curve. α/β is inversely proportional to biological sensitivity to
To the Editor: The French Society of Young Radiation Oncologists (SFjRO) has created an iPhone application (Fig 1) that allows for calculation of biologically equivalent doses in clinical radiotherapy using the linear-quadratic model. An English version was made available in November 2010, downloaded by more than 900 people over the world (United States, United Kingdom, Germany, The Netherlands, etc).1 It is available on iOS for iPhone, iPod Touch, and iPad. A web version (in French, English, German, and Spanish) can be used inside any browser (http://www.sfjro.fr). The application is also available for Google's mobile OS Android. The application was developed with 2 goals in mind: (1) To provide radiation oncologists with a ready-to-use
Figure 1
eLQ screenshots.
⁎ Corresponding author. 3 rue Frédéric Combemale, 59000 Lille, France. E-mail address: [email protected] (J.E. Bibault). 1879-8500/$ – see front matter © 2011 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.prro.2011.04.001
Practical Radiation Oncology: July-September 2011
different fractionation regimens. If α/β N10 Gy, the biological response would be unlikely changed by modified fractionation. Conversely, an α/β value b10 Gy would be associated with a significant impact of dose per fraction alteration, especially when late reactions of organs at risk are considered.5 Since the validity of the linear-quadratic model has only been established for doses per fraction between 1 and 6-8 Gy,2-5our application should not be used for largely hypofractionated regimens. Additionally, we did not include correction for incomplete repair between fractions or for cell proliferation; our application should not be used when the interval between 2 treatment sessions is shorter than 6 to 8 hours or in the case of accelerated treatments. We thank the boards of SFRO and SFjRO for their help and remarks. We would like to invite the journal readership to test eLQ and let us know their comments and suggestions. Jean-Emmanuel Bibault MD Academic Radiation Oncology Department Oscar Lambret Cancer Center, Lille, France (SFjRO, French Society of Young Radiation Oncologists) Pierre Blanchard MD Radiation Oncology Department Institut Gustave Roussy, Paris, France (SFjRO, French Society of Young Radiation Oncologists)
Correspondence
213
Bernard Dubray MD, PhD Département de radiothérapie et de Physique Médicale Centre Henri Becquerel, Rouen, France Eric Lartigau MD, PhD Academic Radiation Oncology Department Oscar Lambret Cancer Center, Lille, France (SFRO, French Society of Radiation Oncologists) On behalf of SFjRO (French Society of Young Radiation Oncologists)
References 1. SFjRO. eLQ available on the App Store; http://itunes.apple.com/us/ app/elq/id398906906?mt=8. Accessed May 11, 2011. 2. Thames HD Jr, Withers HR, Peters LJ, Fletcher GH. Changes in early and late radiation responses with altered dose fractionation: implications for dose-survival relationships. Int J Radiat Oncol Biol Phys. 1982;8:219-226. 3. Joiner MC, Bentzen SM. Fractionation: the linear-quadratic approach. In: Joiner MC, van der Kogel A, eds. Basic clinical radiobiology. 4th ed. Hodder Arnold: London; 2009:102-118. 4. Hall EJ. Time, dose, and fractionation in radiotherapy. In: Radiobiology for the radiologist. 5th ed. Philadelphia: Lippincott Williams & Wilkins; 2000:397-418. 5. Scalliet P, Cosset JM, Wambersie A. Application of the LQ model to the interpretation of absorbed dose distribution in the daily practice of radiotherapy. Radiother Oncol. 1991;22:180-189.
www.practicalradonc.org
Correspondence
eLQ : A biologically-equivalent dose calculator available on iPhone, Android, and the web
tool fitting in a lab coat pocket; and (2) to sensitize young radiation oncologists to radiobiology and the influence of fractionation. The calculator was created using Apple's Xcode Developer Tool Technology with the PhoneGap open source framework and jQtouch. It is the first free calculator that is academically supported. Inside the application, the user is invited to choose an organ at risk or a predefined α/β value, and enter total prescribed dose, initial dose per fraction, and new dose per fraction. The equivalent dose is then calculated. Alerts based on linear-quadratic model limitations and dose constraints for each organ are activated, should any parameters be out of the defined boundaries. The linear-quadratic model is used to predict biological response to radiation when fractionation is altered.2-5 Each organ is characterized by 2 parameters: α represents the cell kill per Gy of the initial linear component and β the cell kill per Gy of the quadratic component of the survival curve. α/β is inversely proportional to biological sensitivity to
To the Editor: The French Society of Young Radiation Oncologists (SFjRO) has created an iPhone application (Fig 1) that allows for calculation of biologically equivalent doses in clinical radiotherapy using the linear-quadratic model. An English version was made available in November 2010, downloaded by more than 900 people over the world (United States, United Kingdom, Germany, The Netherlands, etc).1 It is available on iOS for iPhone, iPod Touch, and iPad. A web version (in French, English, German, and Spanish) can be used inside any browser (http://www.sfjro.fr). The application is also available for Google's mobile OS Android. The application was developed with 2 goals in mind: (1) To provide radiation oncologists with a ready-to-use
Figure 1
eLQ screenshots.
⁎ Corresponding author. 3 rue Frédéric Combemale, 59000 Lille, France. E-mail address: [email protected] (J.E. Bibault). 1879-8500/$ – see front matter © 2011 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved. doi:10.1016/j.prro.2011.04.001
Practical Radiation Oncology: July-September 2011
different fractionation regimens. If α/β N10 Gy, the biological response would be unlikely changed by modified fractionation. Conversely, an α/β value b10 Gy would be associated with a significant impact of dose per fraction alteration, especially when late reactions of organs at risk are considered.5 Since the validity of the linear-quadratic model has only been established for doses per fraction between 1 and 6-8 Gy,2-5our application should not be used for largely hypofractionated regimens. Additionally, we did not include correction for incomplete repair between fractions or for cell proliferation; our application should not be used when the interval between 2 treatment sessions is shorter than 6 to 8 hours or in the case of accelerated treatments. We thank the boards of SFRO and SFjRO for their help and remarks. We would like to invite the journal readership to test eLQ and let us know their comments and suggestions. Jean-Emmanuel Bibault MD Academic Radiation Oncology Department Oscar Lambret Cancer Center, Lille, France (SFjRO, French Society of Young Radiation Oncologists) Pierre Blanchard MD Radiation Oncology Department Institut Gustave Roussy, Paris, France (SFjRO, French Society of Young Radiation Oncologists)
Correspondence
213
Bernard Dubray MD, PhD Département de radiothérapie et de Physique Médicale Centre Henri Becquerel, Rouen, France Eric Lartigau MD, PhD Academic Radiation Oncology Department Oscar Lambret Cancer Center, Lille, France (SFRO, French Society of Radiation Oncologists) On behalf of SFjRO (French Society of Young Radiation Oncologists)
References 1. SFjRO. eLQ available on the App Store; http://itunes.apple.com/us/ app/elq/id398906906?mt=8. Accessed May 11, 2011. 2. Thames HD Jr, Withers HR, Peters LJ, Fletcher GH. Changes in early and late radiation responses with altered dose fractionation: implications for dose-survival relationships. Int J Radiat Oncol Biol Phys. 1982;8:219-226. 3. Joiner MC, Bentzen SM. Fractionation: the linear-quadratic approach. In: Joiner MC, van der Kogel A, eds. Basic clinical radiobiology. 4th ed. Hodder Arnold: London; 2009:102-118. 4. Hall EJ. Time, dose, and fractionation in radiotherapy. In: Radiobiology for the radiologist. 5th ed. Philadelphia: Lippincott Williams & Wilkins; 2000:397-418. 5. Scalliet P, Cosset JM, Wambersie A. Application of the LQ model to the interpretation of absorbed dose distribution in the daily practice of radiotherapy. Radiother Oncol. 1991;22:180-189.