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1.S. Webb, “Motion effects in (intensity modulated) radiation therapy: A review,” Phys. Med. Biol. 51, R403R425 (2006).
2.S. S. Korreman, “Motion in radiotherapy: Photon therapy,” Phys. Med. Biol. 57, R161R191 (2012).
3.K. Otto, “Volumetric modulated arc therapy: IMRT in a single gantry arc,” Med. Phys. 35, 310317 (2008).
4.G. Nicolini, E. Vanetti, A. Clivio, A. Fogliata, and L. Cozzi, “Pre-clinical evaluation of respiratory-gated delivery of volumetric modulated arc therapy with RapidArc,” Phys. Med. Biol. 55, N347N357 (2010).
5.H. A. McNair, J. Brock, J. R. N. Symonds-Tayler, S. Ashley, S. Eagle, P. M. Evans, A. Kavanagh, N. Panakis, and M. Brada, “Feasibility of the use of the active breathing coordinator (ABC) in patients receiving radical radiotherapy for non-small cell lung cancer (NSCLC),” Radiother. Oncol. 93, 424429 (2009).
6.J. Boda-Heggemann, S. Mai, J. Fleckenstein, K. Siebenlist, A. Simeonova, M. Ehmann, V. Steil, F. Wenz, F. Lohr, and F. Stieler, “Flattening-filter-free intensity modulated breath-hold image-guided SABR (Stereotactic ABlative Radiotherapy) can be applied in a 15-min treatment slot,” Radiother. Oncol. 109, 505509 (2013).
7.G. A. Davies, G. Poludniowski, and S. Webb, “MLC tracking for Elekta VMAT: A modelling study,” Phys. Med. Biol. 56, 75417554 (2011).
8.T. Ravkilde, P. J. Keall, C. Grau, M. Høyer, and P. R. Poulsen, “Time-resolved dose distributions to moving targets during volumetric modulated arc therapy with and without dynamic MLC tracking,” Med. Phys. 40, 111723 (8pp.) (2013).
9.E. Chin, S. K. Loewen, A. Nichol, and K. Otto, “4D VMAT, gated VMAT, and 3D VMAT for stereotactic body radiation therapy in lung,” Phys. Med. Biol. 58, 749770 (2013).
10.A. E. Lujan, E. W. Larsen, J. M. Balter, and R. K. Ten Haken, “A method for incorporating organ motion due to breathing into 3D dose calculations,” Med. Phys. 26, 715720 (1999).
11.T. Bortfeld, K. Jokivarsi, M. Goitein, J. Kung, and S. B. Jiang, “Effects of intra-fraction motion on IMRT dose delivery: Statistical analysis and simulation,” Phys. Med. Biol. 47, 22032220 (2002).
12.T. Bortfeld, S. B. Jiang, and E. Rietzel, “Effects of motion on the total dose distribution,” Semin. Radiat. Oncol. 14, 4151 (2004).
13.M. Engelsman, E. M. F. Damen, K. De Jaeger, K. M. van Ingen, and B. J. Mijnheer, “The effect of breathing and set-up errors on the cumulative dose to a lung tumor,” Radiother. Oncol. 60, 95105 (2001).
14.S. B. Jiang, C. Pope, K. M. Al Jarrah, J. H. Kung, T. Bortfeld, and G. T. Y. Chen, “An experimental investigation on intra-fractional organ motion effects in lung IMRT treatments,” Phys. Med. Biol. 48, 17731784 (2003).
15.M. Schaefer, C. Münter, M. W. Thilmann, F. Sterzing, P. Haering, S. E. Combs, and J. Debus, “Influence of intra-fractional breathing movement in step-and-shoot IMRT,” Phys. Med. Biol. 49, N175N179 (2004).
16.C. Vranĉić, A. Trofimov, T. C. Y. Chan, G. C. Sharp, and T. Bortfeld, “Experimental evaluation of a robust optimization method for IMRT of moving targets,” Phys. Med. Biol. 54, 29012914 (2009).
17.E. D. Ehler, B. E. Nelms, and W. A. Tomé, “On the dose to a moving target while employing different IMRT delivery mechanisms,” Radiother. Oncol. 83, 4956 (2007).
18.C. Stambaugh, B. E. Nelms, T. Dilling, C. Stevens, K. Latifi, G. Zhang, E. Moros, and V. Feygelman, “Experimentally studied dynamic dose interplay does not meaningfully affect target dose in VMAT SBRT lung treatments,” Med. Phys. 40, 091710(8pp.) (2013).
19.J. Seco, G. C. Sharp, Z. Wu, D. Gierga, F. Büttner, and H. Paganetti, “Dosimetric impact of motion in free-breathing and gated lung radiotherapy: A 4D Monte Carlo study of intrafraction and interfraction effects,” Med. Phys. 35, 356366 (2008).
20.J. Seco, D. Robertson, A. Trofimov, and H. Paganetti, “Breathing interplay effects during proton beam scanning: Simulation and statistical analysis,” Phys. Med. Biol. 54, N283N294 (2009).
21.M. Oliver, A. Gladwish, R. Staruch, J. Craig, S. Gaede, J. Chen, and E. Wong, “Experimental measurements and Monte Carlo simulations for dosimetric evaluations of intrafraction motion for gated and ungated intensity modulated arc therapy deliveries,” Phys. Med. Biol. 53, 64196436 (2008).
22.Y. D. Mutaf, C. J. Scicutella, D. Michalski, K. Fallon, E. D. Brandner, G. Bednarz, and M. S. Huq, “A simulation study of irregular respiratory motion and its dosimetric impact on lung tumors,” Phys. Med. Biol. 56, 845859 (2011).
23.L. Court, M. Wagar, R. Berbeco, A. Reisner, B. Winey, D Schofield, D. Ionascu, A. M. Allen, R. Popple, and T. Lingos, “Evaluation of the interplay effect when using RapidArc to treat targets moving in the craniocaudal or right-left direction,” Med. Phys. 37, 411 (2010).
24.J. G. Li and L. Xing, “Inverse planning incorporating organ motion,” Med. Phys. 27, 15731578 (2000).
25.P. J. Keall, G. S. Mageras, J. M. Balter, R. S. Emery, K. M. Forster, S. B. Jiang, J. M. Kapatoes, D. A. Low, M. J. Murphy, B. R. Murray, C. R. Ramsey, M. B. van Herk, S. S. Vedam, J. W. Wong, and E. Yorke, “The management of respiratory motion in radiation oncology report of AAPM task group 76,” Med. Phys. 33, 38743900 (2006).
26.M. van Herk, “Different styles of image-guided radiotherapy,” Semin. Radiat. Oncol. 17, 258267 (2007).
27.C. Cameron, “Sweeping-window arc therapy: An implementation of rotational IMRT with automatic beam-weight calculation,” Phys. Med. Biol. 50, 43174336 (2005).
28.C. X. Yu, D. A. Jaffray, and J. W. Wong, “The effects of intra-fraction organ motion on the delivery of dynamic intensity modulation,” Phys. Med. Biol. 43, 91104 (1998).
29.S. Ulrich, S. Nill, and U. Oelfke, “Development of an optimization concept for arc-modulated cone beam therapy,” Phys. Med. Biol. 21, 40994119 (2007).
30.D. Georg, T. Knöös, and B. McClean, “Current status and future perspective of flattening filter free photon beams,” Med. Phys. 38, 12801293 (2011).
31.A. Nimierko, “Reporting and analyzing dose distributions: A concept of equivalent uniform dose,” Med. Phys. 24, 103110 (1997).
32.Q. Wu, R. Mohan, A. Nimierko, and R. Schmidt-Ulrich, “Optimization of intensity-modulated radiotherapy plans based on equivalent uniform dose,” Int. J. Radiat. Oncol., Biol., Phys. 52, 224235 (2002).
33.V. Gregoire, T. R. Mackie, W. De Neuve, M. Gospodarowicz, J. A. Purdy, M. van Herk, and A. Nimierko, “ICRU report 83: Presribing, recording and reporting photon-beam intensity-modulated radiation therapy (IMRT),” J. ICRU 10, 1106 (2010).
34.R. George, S. S. Vedam, T. D. Chung, V. Ramakrishnan, and P. J. Keall, “The application of the sinusoidal model to lung cancer patient respiratory motion,” Med. Phys. 32, 28502861 (2005).
35.Y. Seppenwoolde, H. Shirato, K. Kitamura, S. Shimizu, M. van Herk, J. V. Lebesque, and K. Miyasaka, “Precise and real-time measurement of 3D tumor motion in lung due to breathing and heartbeat, measured during radiotherapy,” Int. J. Radiat. Oncol., Biol., Phys. 53, 822834 (2002).
36.H. Shirato, A. Seppenwoolde, K. Kitamura, R. Onimura, and S. Shimizu, “Intrafractional tumor motion: Lung and liver,” Semin. Radiat. Oncol. 14, 1018 (2004).
37.M. Söhn, B. Sobotta, and M. Alber, “Dosimetric treatment course simulation based on a statistical model of deformable organ motion,” Phys. Med. Biol. 57, 36933709 (2012).
38.Z. Hui, X. Zhang, G. Starkschall, Y. Li, R. Mohan, R. Komaki, J. D. Cox, and J. Y. Chang, “Effects of intrafractional motion and anatomic changes on proton therapy dose distributions in lung cancer,” Int. J. Radiat. Oncol., Biol., Phys. 72, 13851395 (2008).

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Due to the potentially periodic collimator dynamic in volumetric modulated arc therapy (VMAT) dose deliveries with the sweeping-window arc therapy (SWAT) technique, additional manifestations of dosimetric deviations in the presence of intrafractional motion may occur. With a fast multileaf collimator (MLC), and a flattening filter free dose delivery, treatment times close to 60 s per fraction are clinical reality. For these treatment sequences, the human breathing period can be close to the collimator sweeping period. Compared to a random arrangement of the segments, this will cause a further degradation of the dose homogeneity.

Fifty VMAT sequences of potentially moving target volumes were delivered on a two dimensional ionization chamber array. In order to detect interplay effects along all three coordinate axes, time resolved measurements were performed twice—with the detector aligned in vertical () or horizontal () orientation. All dose matrices were then moved within a simulation software by a time-dependent motion vector. The minimum relative equivalent uniform dose EUD for all breathing starting phases was determined for each amplitude and period. Furthermore, an estimation of periods with minimum EUD was performed. Additionally, LINAC logfiles were recorded during plan delivery. The MLC, jaw, gantry angle, and monitor unit settings were continuously saved and used to calculate the correlation coefficient between the target motion and the dose weighed collimator motion component for each direction (CC, LR, AP) separately.

The resulting EUD were EUD(CC) = (98.3 ± 0.6)%, EUD(CC) = (98.6 ± 0.5)%, EUD(AP) = (97.7 ± 0.9)%, and EUD(LR) = (97.8 ± 0.9)%. The overall minimum relative EUD observed for 360 arc midventilation treatments was 94.6%. The treatment plan with the shortest period and a minimum relative EUD of less than 97% was found at = 6.1 s. For a partial 120 arc, an EUD = 92.0% was found. In all cases, a correlation coefficient above 0.5 corresponded to a minimum in EUD.

With the advent of fast VMAT delivery techniques, nonrobust treatment sequences for human breathing patterns can be generated. These sequences are characterized by a large correlation coefficient between a target motion component and the corresponding collimator dynamic. By iteratively decreasing the maximum allowed dose rate, a low correlation coefficient and consequentially a robust treatment sequence are ensured.


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