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Evaluation of PTV margins in IMRT for head and neck cancer and prostate cancer

Published online by Cambridge University Press:  17 February 2020

M. A. Youssoufi ,
M. Bougtib ,
S. Douama ,
M. Ait Erraisse ,
F. Z. Abboud ,
K. Hassouni  and
F. Bentayeb Open the ORCID record for F. Bentayeb [Opens in a new window]
M. A. Youssoufi
Affiliation:
Faculty of Sciences (LPHE, M-S), University Mohammed V, Rabat, Morocco Department of Radiotherapy, University Hospital Hassan II, Fes, Morocco
M. Bougtib
Affiliation:
Faculty of Sciences (LPHE, M-S), University Mohammed V, Rabat, Morocco Department of Radiotherapy, University Hospital Hassan II, Fes, Morocco
S. Douama
Affiliation:
Faculty of Sciences (LPHE, M-S), University Mohammed V, Rabat, Morocco
M. Ait Erraisse
Affiliation:
Department of Radiotherapy, University Hospital Hassan II, Fes, Morocco
F. Z. Abboud
Affiliation:
Department of Radiotherapy, University Hospital Hassan II, Fes, Morocco
K. Hassouni
Affiliation:
Department of Radiotherapy, University Hospital Hassan II, Fes, Morocco
F. Bentayeb*
Affiliation:
Faculty of Sciences (LPHE, M-S), University Mohammed V, Rabat, Morocco
*
Author for correspondence: F. Bentayeb, Department of Physics, Faculty of Sciences, B.P. 1014, 10000Rabat, Morocco. Tel: +00212 668460012. E-mail: bentayebfr@yahoo.fr
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Abstract

Purpose:

The aim of this study was to evaluate planning target volume (PTV) margins for two different locations using an electronic portal imaging device (EPID) to ensure that the correct radiation dose is delivered to the tumour when using intensity-modulated radiation therapy (IMRT).

Materials and methods:

Setup data were collected from 40 patients treated with IMRT for head and neck cancer (HN) (20 patients) and prostate cancer (20 patients). Setup errors from 720 registration images were analysed to evaluate systematic and random errors. Thereafter, optimal PTV margins were calculated based on International Commission on Radiation Units and Measurements 62 (ICRU), Stroom and Parker formulas compared with the Van Herk’s recipe.

Results:

To calculate the margins around the PTV, several different formulas have been used. Setup margins ranged between 2–4·3, 2·2–4·6 and 2·1–4·7 mm in X, Y and Z directions, respectively, for HN cases. Similarly, for the prostate site, setup margins ranged between 3·7–8·3, 3·2–6·8 and 3·3–8·2 mm in X, Y and Z directions.

Conclusion:

To ensure better coverage of target volume, we adopted a PTV margin of 5 mm for HN PTVs and 10 mm for prostate PTVs in our department.

Keywords

electronic portal imaging devicehead and neckplanning target volumeprostate
Type
Technical Note
Information
Journal of Radiotherapy in Practice , Volume 20 , Issue 1 , March 2021 , pp. 114 - 119
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Copyright
© The Author(s), 2020. Published by Cambridge University Press

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References

Tommasino, F, Nahum, A, Cella, L. Increasing the power of tumour control and normal tissue complication probability modelling in radiotherapy: recent trends and current issues. Transl Cancer Res 2017; 6 (S5): 807–821.CrossRefGoogle Scholar
Khan, F M. The Physics of Radiation Therapy: Lippincott Williams & Wilkins, 4th edition. Minneapolis, MN, USA: University of Minnesota Medical School, 2009.Google Scholar
ICRU: Prescribing, Recording, and Reporting Photon-Beam Intensity-Modulated Radiation Therapy (IMRT). ICRU Report 83, J. ICRU, Volume 10(1). Oxford University Press, Oxford, UK, 2010.CrossRefGoogle Scholar
Jaffray, D A, Katja, L, Mageras, G et al. Assuring safety and quality in image guided delivery of radiation therapy. Practical Radiat Oncol 2013; 3: 167–170.CrossRefGoogle Scholar
Tejpal, G, Supriya, C, Avinash, K et al. Assessment of three-dimensional set-up errors in conventional head and neck radiotherapy using electronic portal imaging device. Radiat Oncol 2007; 2: 44–51.Google Scholar
Langmack, K A. Portal imaging. Br J Radiol 2001; 74: 789–794.CrossRefGoogle ScholarPubMed
Evrim, B, OZlem, A, Münir, K, Fadime, A. How to determine margins for planning target volume (PTV): from 2D to 3D planning in radiotherapy for head and neck cancer. Portal imaging assessment for set-up errors. Turkish J Oncol 2010; 25: 104–110.Google Scholar
International Commision on Radiation Units and Measurements: Prescribing, recording and reporting photon beam therapy (Supplement to ICRU report 50). In ICRU Report, 62. Bethesda, MD: ICRU Publications, 2000.Google Scholar
Stroom, J C, de Boer, H C, Huizenga, H et al. Inclusion of geometrical uncertainties in radiotherapy treatment planning by means of coverage probability. Int J Radiat Oncol Biol Phys 1999; 43: 905–919.CrossRefGoogle ScholarPubMed
Parker, B C, Shiu, A S, Maor, M H et al. PTV margin determination in conformal SRT of intracranial lesions. J Appl Clin Med Phys 2002; 3: 176–189.CrossRefGoogle ScholarPubMed
Van Herk, M, Remeijer, P, Rasch, C, Lebesque, J V. The probability ofcorrect target dose: dose population histograms for deriving treatment margins in radiotherapy. Int J Radiat Oncol Biol Phys 2000; 47: 1121–1135.CrossRefGoogle Scholar
Van Herk, M. Errors and margins in radiotherapy. Semin Radiat Oncol 2004; 14: 52–64.CrossRefGoogle ScholarPubMed
Bel, A, Keus, R, Vijlbrief, R E, Lebesque, J V. Setup deviations in wedged pair irradiation of parotid gland and tonsillar tumors, measured with an electronic portal imaging device. Radiother Oncol 1995; 37: 153–159.CrossRefGoogle ScholarPubMed
de Boer, H C, de Koste, J R V S, Creutzberg, C L et al. Electronic portal image assisted reduction of systematic set-up errors in head and neck irradiation. Radiother Oncol 2001; 61:299–208.CrossRefGoogle ScholarPubMed
Van Herk, M, Remeijer, P, Lebesque, J V. Inclusion of geometric uncertainties in treatment plan evaluation. Int J Radiat Oncol Biol Phys 2002; 52:1407–1422.CrossRefGoogle ScholarPubMed
Wortel, R C, Incrocci, L, Pos, F J et al. Acute toxicity after image-guided intensity modulated radiation therapy compared to 3D conformal radiation therapy in prostate cancer patients. Int J Radiat Oncol Biol Phys 2015; 91: 737–744.CrossRefGoogle ScholarPubMed
Perera, T, Moseley, J, Munro, P. Subjectivity in interpretation of portal films. Int J Radiat Oncol Biol Phys 1999; 45: 529–534.CrossRefGoogle ScholarPubMed
Skarsgard, D, Cadman, P, El-Gayed, A et al. Planning target volume margins for prostate radiotherapy using daily electronic portal imaging and implanted fiducial markers. Radiat Oncol 2010 Jun 10; 5: 52–62.CrossRefGoogle ScholarPubMed
Graf, R, Wust, P, Budach, V, Boehmer, D. Potentials of on-line repositioning based on implanted fiducial markers and electronic portal imaging in prostate cancer radiotherapy. Radiat Oncol 2009; 4: 13–21.CrossRefGoogle ScholarPubMed
Beltran, C, Herman, M, Davis, B. Planning target margin calculations for prostate radiotherapy based on intrafraction and interfraction motion using four localization methods. Int J Radiat Oncol Biol Phys 2008 Jan 1; 70 (1): 289–295.CrossRefGoogle ScholarPubMed
Suzuki, M, Nishimura, Y, Nakamatsu, K et al. Analysis of interfractional set-up errors and intrafraction organ motions during IMRT for head and neck tumors to define anappropriate planning target volume (PTV)- and planning organs at risk volume (PRV)-margins. Radiother Oncol 2006; 78: 283–290.CrossRefGoogle Scholar
Gilbeau, L, Octave-Prignot, M, Loncol, T et al. Comparison of set up accuracy of three different thermoplastic masks for the treatment of brain and head and neck tumors. Radiother Oncol 2001; 58: 155–162.CrossRefGoogle Scholar