Abstract
Transmission dosimetry has the potential for identifying dosimetry errors during radiotherapy treatments by detecting changes in effective beam path between the planned and delivered treatment geometry. In the current study, the Pinnacle treatment planning system was used to model transmitted dose in a “virtual” EPID to investigate the possibility of using transmission dosimetry for detecting patient breathing and setup errors in breast conformal radiotherapy treatments. An opposing tangential beams treatment plan was used as a proof-of-principle study for deliberately introducing shifts in the position of the beams and virtual EPID relative to the CT data, to simulate shallow and deep breathing excursions of 2 mm and 11 mm, respectively. In addition, breathing was combined with setup errors of 0 mm and 2.5 mm in a given direction for each beam. Due to spatial limitations in the original CT data, the CT data was modified to include an additional volume of air surrounding the patient to allow for the virtual EPID to be modelled at sufficient distances from the beam focus. Breathing excursions of both 2 mm and 11 mm could be detected in the transmitted dose planes below the patient. Breathing combined with a 2.5 mm set up errors in the superior-inferior direction further accentuated the distribution of the dose errors in the superior-inferior directions. The predicted changes in transmitted dose due to the simulated delivery errors shows promise for using transmitted dosimetry in the clinic.
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Dahlgren, C. V., Ahnesjo, A., Montelius, A. and Rikner, G.Portal dose image verification: formalism and application of the collapsed cone superposition method, Phys. Med. Biol., 47(24): 4371–4387., 2002.
McCurdy, B. M., Luchka, K. and Pistorius, S.Dosimetric investigation and portal dose image prediction using an amorphous silicon electronic portal imaging device, Med. Phys., 28(6): 911–924., 2001.
McNutt, T. R., Mackie, T. R., Reckwerdt, P., Papanikolaou, N, and Paliwal, B. R.Calculation of portal dose using the convolution/superposition method, Med. Phys., 23(4): 527–535., 1996.
Pasma, K. L., Heijmen, B. J., Kroonwijk, M. and Visser, A. G.Portal dose image (PDI) prediction for dosimetric treatment verification in radiotherapy. I. An algorithm for open beams, Med. Phys., 25(6): 830–840., 1998.
Reich, P., Bezak, E., Mohammadi, M. and Fog, L.The prediction of transmitted dose distributions using a 3D treatment planning system, Australas. Phys. Eng. Sci. Med., 29(1): 18–29, 2006.
Siebers, J. V., Kim, J. O., Ko, L., Keall, P. J. and Mohan, R.Monte Carlo computation of dosimetric amorphous silicon electronic portal images, Med. Phys., 31(7): 2135–2146., 2004.
van Elmpt, W. J., Nijsten, S. M., Mijnheer, B. J. and Minken, A. W.Experimental verification of a portal dose prediction model, Med. Phys., 32(9): 2805–2818., 2005.
Van Esch, A., Vanstraelen, B., Verstraete, J., Kutcher, G. and Huyskens, D.Pre-treatment dosimetric verification by means of a liquid-filled electronic portal imaging device during dynamic delivery of intensity modulated treatment fields, Radiother. Oncol., 60(2): 181–190., 2001.
Wong, J. W., Slessinger, E. D., Hermes, R. E., Offutt, C. J., Roy, T. and Vannier, M. W.Portal dose images. I: Quantitative treatment plan verification, Int. J. Radiat. Oncol. Biol. Phys., 18(6): 1455–1463., 1990.
Essers, M. and Mijnheer, B. J.In vivo dosimetry during external photon beam radiotherapy, Int. J. Radiat. Oncol. Biol. Phys., 43(2): 245–259, 1999.
Herbert, C. E., Ebert, M. A. and Joseph, D. J.Feasible measurement errors when undertaking in vivo dosimetry during external beam radiotherapy of the breast, Med. Dosim., 28(1): 45–48, 2003.
Heukelom, S., Lanson, J. H. and Mijnheer, B. J.In vivo dosimetry during pelvic treatment, Radiother. Oncol., 25(2): 111–120, 1992.
Morton, J. P., Bhat, M., Kovendy, A. and Williams, T.Evaluation of MOSFETs for entrance dose dosimetry for 6 and 10 MV photons with a custom made build up cap, Australas. Phys. Eng. Sci. Med., 30(2): 120–126, 2007.
Piermattei, A., Fidanzio, A., Azario, L., Grimaldi, L., D’Onofrio, G., Cilla, S., Stimato, G., Gaudino, D., Ramella, S., D’Angelillo, R., Cellini, F., Trodella, L., Russo, A., Iadanza, L., Zucca, S., Fusco, V., Di Napoli, N., Gambacorta, M. A., Balducci, M., Cellini, N., Deodato, F., Macchia, G. and Morganti, A. G.Application of a practical method for the isocenter point in vivo dosimetry by a transit signal, Phys. Med. Biol., 52(16): 5101–5117, 2007.
Tung, C. J., Wang, H. C., Lo, S. H., Wu, J. M. and Wang, C. J.In vivo dosimetry for external photon treatments of head and neck cancers by diodes and TLDS, Radiat. Prot. Dosimetry, 111(1): 45–50, 2004.
Ansbacher, W.Three-dimensional portal image-based dose reconstruction in a virtual phantom for rapid evaluation of IMRT plans, Med. Phys., 33(9): 3369–3382., 2006.
Boellaard, R., van Herk, M. and Mijnheer, B. J.A convolution model to convert transmission dose images to exit dose distributions, Med. Phys., 24(2): 189–199., 1997.
Hansen, V. N., Evans, P. M. and Swindell, W.The application of transit dosimetry to precision radiotherapy, Med. Phys., 23(5): 713–721., 1996.
McNutt, T. R., Mackie, T. R., Reckwerdt, P. and Paliwal, B. R.Modeling dose distributions from portal dose images using the convolution/superposition method, Med. Phys., 23(8): 1381–1392., 1996.
Partridge, M., Ebert, M. and Hesse, B. M.IMRT verification by three-dimensional dose reconstruction from portal beam measurements, Med. Phys., 29(8): 1847–1858., 2002.
Wendling, M., Louwe, R. J., McDermott, L. N., Sonke, J. J., van Herk, M. and Mijnheer, B. J.Accurate two-dimensional IMRT verification using a back-projection EPID dosimetry method, Med. Phys., 33(2): 259–273., 2006.
van Elmpt, W. J., Nijsten, S. M., Schiffeleers, R. F., Dekker, A. L., Mijnheer, B. J., Lambin, P. and Minken, A. W. A Monte Carlo based three-dimensional dose reconstruction method derived from portal dose images, Med. Phys., 33(7): 2426–2434, 2006.
Dahlgren, C. V., Eilertsen, K., Jorgensen, T. D. and Ahnesjo, A.Portal dose image verification: the collapsed cone superposition method applied with different electronic portal imaging devices, Phys. Med. Biol., 51(2): 335–349. Epub 2006 Jan 2004., 2006.
Pasma, K. L., Vieira, S. C. and Heijmen, B. J.Portal dose image prediction for dosimetric treatment verification in radiotherapy. II. An algorithm for wedged beams, Med. Phys., 29(6): 925–931., 2002.
Fielding, A. L., Evans, P. M. and Clark, C. H.Verification of patient position and delivery of IMRT by electronic portal imaging, Radiother. Oncol., 73(3): 339–347, 2004.
Lamberts, K., Nijsten, S., Lambin, P. and Minken, A. 2005 Qualitative determination of errors causing portal transit dose differences using gamma evaluation parameters. In:8th Biennial ESTRO Meeting on Physics and Radiation Technology for Clinical Radiotherapy, (Lisbon, Portugal pp S131–S132
Depuydt, T., Van Esch, A. and Huyskens, D. P.A quantitative evaluation of IMRT dose distributions: refinement and clinical assessment of the gamma evaluation, Radiother. Oncol., 62(3): 309–319, 2002.
George, R, Keall, P. J., Kini, V. R., Vedam, S. S., Siebers, J. V., Wu, Q., Lauterbach, M. H., Arthur, D. W. and Mohan, R.Quantifying the effect of intrafraction motion during breast IMRT planning and dose delivery, Med. Phys., 30(4): 552–562, 2003.
Frazier, R. C., Vicini, F. A., Sharpe, M. B., Yan, D., Fayad, J., Baglan, K. L., Kestin, L. L., Remouchamps, V. M., Martinez, A. A. and Wong, J. W.Impact of breathing motion on whole breast radiotherapy: a dosimetric analysis using active breathing control, Int. J. Radiat. Oncol. Biol. Phys., 58(4): 1041–1047, 2004.
Hector, C. L., Webb, S. and Evans, P. M.The dosimetric consequences of inter-fractional patient movement on conventional and intensity-modulated breast radiotherapy treatments, Radiother. Oncol., 54(1): 57–64, 2000.
Saliou, M. G., Giraud, P., Simon, L., Fournier-Bidoz, N., Fourquet, A., Dendale, R., Rosenwald, J. C. and Cosset, J. M.[Radiotherapy for breast cancer: respiratory and set-up uncertainties], Cancer Radiother., 9(6–7): 414–421, 2005.
McDermott, L. N., Wendling, M., Sonke, J. J., van Herk, M. and Mijnheer, B. J.,Anatomy changes in radiotherapy detected using portal imaging, Radiother. Oncol., 79(2): 211–217. Epub 2006 May 2015., 2006.
Kroonwijk, M., Pasma, K. L., Quint, S., Koper, P. C., Visser, A. G. and Heijmen, B. J.In vivo dosimetry for prostate cancer patients using an electronic portal imaging device (EPID); demonstration of internal organ motion, Radiother. Oncol., 49(2): 125–132., 1998.
Mohammadi, M. and Bezak, E.,Two dimensional transmitted dose measurements using a liquid ionisation chamber EPID, Phys. Med. Biol., 51(1–15, 2006.
Chin, P. W., Spezi, E. and Lewis, D. G.Monte Carlo simulation of portal dosimetry on a rectilinear voxel geometry: a variable gantry angle solution, Phys. Med. Biol., 48(16): N231–238., 2003.
Kubo, H. D. and Hill, B. C.Respiration gated radiotherapy treatment: a technical study, Phys. Med. Biol., 41(1): 83–91, 1996.
Mavroidis, P., Axelsson, S., Hyodynmaa, S., Rajala, J., Pitkanen, M. A., Lind, B. K. and Brahme, A.,Effects of positioning uncertainty and breathing on dose delivery and radiation pneumonitis prediction in breast cancer, Acta Oncol, 41(5): 471–485, 2002.
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Reich, P.D., Bezak, E. The use of a treatment planning system to investigate the potential for transmission dosimetry in detecting patient breathing during breast 3D CRT. Australas. Phys. Eng. Sci. Med. 31, 110–121 (2008). https://doi.org/10.1007/BF03178585
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DOI: https://doi.org/10.1007/BF03178585