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Calypso’s array attenuation

Published online by Cambridge University Press:  05 March 2015

Célia Silva ,
Dalila Mateus ,
Sandra Vieira ,
Milton Rodrigues ,
Margarida Eiras  and
Carlo Greco
Célia Silva*
Affiliation:
Centro Clínico Fundação Champalimaud, Lisboa, Portugal Escola Superior de Tecnologias da Saúde de Lisboa, Portugal
Dalila Mateus
Affiliation:
Centro Clínico Fundação Champalimaud, Lisboa, Portugal
Sandra Vieira
Affiliation:
Centro Clínico Fundação Champalimaud, Lisboa, Portugal
Milton Rodrigues
Affiliation:
Centro Clínico Fundação Champalimaud, Lisboa, Portugal
Margarida Eiras
Affiliation:
Escola Superior de Tecnologias da Saúde de Lisboa, Portugal
Carlo Greco
Affiliation:
Centro Clínico Fundação Champalimaud, Lisboa, Portugal
*
Correspondence to: Célia Silva, R. Outeiro Cacho, 6, Loureira, 2495-161 Sta Cat Serra, Portugal. Tel: 00351919628745. E-mail: [email protected]
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Abstract

Introduction

The Calypso 4D Localization System gives the possibility to track the tumour during treatment, with no additional ionising radiation delivered. To monitor the patient continuously an array is positioned above the patient during the treatment. We intend to study, for various gantry angles, the attenuation effect of the array for 6- and 10 MV and flattening filter free (FFF) 6- and FFF 10 MV photon beams.

Materials and methods

Measurements were performed using an ion chamber placed in a slab phantom positioned at the linac isocenter for 6 MV, 10 MV, FFF 6 MV and FFF 10 MV photon beams. Measurements were performed with and without array above the phantom for 0°, 10°, 20°, 40° and 50° beam angle for a True Beam STx linac, for 5×5 and 10×10 and 15×15 cm2 field size beams to evaluate the attenuation of the array. A VMAT treatment plan was measured using an ArcCheck with and without the array in the beam path.

Results and discussion

Attenuation measured values were up to 3%. Attenuation values were between 1 and 2% with the exception of the 30°–50° gantry angles which were up to 3.3%. The ratio values calculated in the ArcCheck for relative dose and absolute dose 10 were both 1·00.

Conclusion

Attenuation of the treatment beam by the Calypso array is within acceptable limits.

Keywords

ArcCheckarrayattenuationCalypso
Type
Original Articles
Information
Journal of Radiotherapy in Practice , Volume 14 , Issue 2 , June 2015 , pp. 202 - 207
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Copyright
© Cambridge University Press 2015 

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References

1.Schweikard, A, Shiomi, H, Adler, J. Respiration tracking in radiosurgery. Med Phys 2004; 31: 2738–2741.Google Scholar
2.Meeks, S L, Bova, F J, Wagner, T Het al. Image localization for frameless stereotactic radiotherapy. Int J Radiat Oncol Biol Phys 2000; 46: 1291–1299.Google Scholar
3.Bova, F J, Meeks, S L, Friedman, W Aet al. Optic-guided stereotactic radiotherapy. Med Dosim 1998; 23: 221–228.Google Scholar
4.Roberts, D W, Strohbein, J W, Hatch, J F. A frameless stereotactic computerized tomographic imaging and the operating microscope. J Neurosurg 1986; 65: 545–549.CrossRefGoogle Scholar
5.Watanabe, E, Mayanagi, Y, Kosugi, Yet al. Open surgery assisted by the articulated, sensitive arm. Neurosurgery 1991; 28: 792–800.CrossRefGoogle ScholarPubMed
6.Suess, O, Suess, S, Mularksi, Set al. Study on the clinical application of pulsed DC magnetic technology for tracking of intraoperative head motion during frameless stereotaxy. Head Face Med 2006; 2: 10.CrossRefGoogle Scholar
7.Keall, P J, Todor, A D, Vedam, S Set al. On the use of EPID-based implanted marker tracking for 4D radiotherapy. Med Phys 2004; 31: 3492–3499.Google Scholar
8.Meeks, S L, Buatti, J M, Bouchet, L Get al. Ultrasound-guided extracranial radiosurgery: technique and application. Int J Radiat Oncol Biol Phys 2003; 55: 1092–1101.Google Scholar
9.Tome, W A, Meeks, S L, Orton, N Pet al. Commissioning and quality assurance of an optically guided three-dimensional ultrasound target localization system for radiotherapy. Med Phys 2002; 29: 1781–1788.Google Scholar
10.Sharp, G C, Jiang, S B, Shimizu, Set al. Tracking errors in a prototype real-time tumor tracking system. Phys Med Biol 2004; 49: 5347–5356.CrossRefGoogle Scholar
11.Stieler, F, Wenz, F, Shi, M, Lohr, F. A novel surface imaging system for patient positioning and surveillance during radiotherapy: a phantom study and clinical evaluation. Strahlenther Onkol 2013; 189: 938–944.Google Scholar
12.Litzenberg, D W, Willoughby, T R, Balter, J Met al. Positional stability of electromagnetic transponders used for prostate localization and continuous, real-time tracking system and on-board kilovoltage imaging system. Int J Radiat Oncol Biol Phys 2007; 68 (4): 1199–1206.Google Scholar
13.Quigley, M M, Mate, T P, Sylvester, J E. Prostate tumor alignment and continuous, real-time adaptive radiation therapy using electromagnetic fiducials: clinical and cost-utility analyses. Urol Oncol 2009; 27: 473–482.Google Scholar
14.Santanam, L, Malinowski, K, Hubenshmidt, Jet al. Fiducial-based translational localization accuracy of electromagnetic tracking system and on-board kilovoltage imaging system. Int J Radiat Oncol Biol Phys 2008; 70 (3): 892–899.CrossRefGoogle ScholarPubMed
15.Li, H S, Chetty, I J, Enke, C Het al. Dosimetric consequences of intrafraction prostate motion. Int J Radiat Oncol Biol Phys 2008; 71 (3): 801–812.CrossRefGoogle ScholarPubMed
16.Zou, W, Betancourt, R, Yin, L, Metz, J, Avery, S, Kassaee, A. Effects on the photon beam from an electromagnetic array used for patient localization and tumor tracking. J Appl Clin Med Phys 2013; 14 (3): 72–80.Google Scholar
17.Myint, K, Niedbala, M, Wilkins, D, Gerig, L H. Investigating treatment dose error due to beam attenuation by a carbon fiber tabletop. J Appl Clin Med Phys 2006; 7 (3): 21–27.Google Scholar
18.Njeh, C F, Raines, T W, Saunders, M W. Determination of the photon beam attenuation by the BrainLAB imaging couch: angular and field size dependence. J Appl Clin Med Phys 2009; 10 (3): 16–27.Google Scholar
19.Seppälä, J K H, Kulmala, J A J. Increased beam attenuation and surface dose by different couch inserts of treatment tables used in megavoltage radiotherapy. J Appl Clin Med Phys 2011; 12 (4): 15–23.CrossRefGoogle ScholarPubMed