Current status and future perspective of flattening filter free photon beams

Medical Physics

Volumn 38, Issue 3, 2011, Pages 1280-1293

  Georg, Dietmar ^a,b,c   Knöös, Tommy ^a,b,c   McClean, Brendan ^a,b,c  

^a MEDICAL UNIVERSITY OF VIENNA   (Austria)

^b ST LUKE S HOSPITAL   (Ireland)

^c LUND UNIVERSITY   (Sweden)

Author keywords

dosimetry; intensity modulated radiotherapy; stereotactic radiotherapy; unflattened beams

Indexed keywords

DOSIMETRY; LINEAR ACCELERATORS; PARTICLE BEAMS; PHOTOELECTRONS; PHOTONS; QUALITY ASSURANCE; RADIOTHERAPY;

FLATTENING FILTER FREE; FUTURE PERSPECTIVES; INTENSITY-MODULATED RADIOTHERAPY; MEDICAL ACCELERATOR; PHOTON BEAM THERAPY; STEREOTACTIC RADIOTHERAPY; TREATMENT PLANNING; UNFLATTENED BEAMS;

RADIATION PROTECTION;

EID: 79952148081     PISSN: 00942405     EISSN: None     Source Type: Journal    
DOI: 10.1118/1.3554643     Document Type: Article

References (118)

1. J. Milan and R. E. Bentley, " The storage and manipulation of radiation dose data in a small digital computer.," Br. J. Radiol. 0007-1285 47, 115-121 (1974). 10.1259/0007-1285-47-554-115
2. J. Izewska, " Shaping of photon beams from electron linear accelerators in radiation therapy.," Med. Phys. 0094-2405 20, 171-177 (1993). 10.1118/1.597133 (Pubitemid 23069872)
3. A. Ahnesjö and M. M. Aspradakis, " Dose calculations for external photon beams in radiotherapy.," Phys. Med. Biol. 0031-9155 44, R99-R155 (1999).
4. A. Ahnesjö, T. Knöös, and A. Montelius, " Application of the convolution method for calculation of output factors for therapy photon beams.," Med. Phys. 0094-2405 19, 295-301 (1992). 10.1118/1.596859
5. M. Fippel, F. Haryanto, O. Dohm, F. Nusslin, and S. Kriesen, " A virtual photon energy fluence model for Monte Carlo dose calculation.," Med. Phys. 0094-2405 30, 301-311 (2003). 10.1118/1.1543152 (Pubitemid 36337095)
6. D. A. Jaffray, J. J. Battista, A. Fenster, and P. Munro, " X-ray sources of medical linear accelerators: Focal and extra-focal radiation.," Med. Phys. 0094-2405 20, 1417-1427 (1993). 10.1118/1.597106 (Pubitemid 24064554)
7. J. Olofsson, D. Georg, and M. Karlsson, " A widely tested model for head scatter influence on photon beam output.," Radiother. Oncol. 0167-8140 67, 225-238 (2003). 10.1016/S0167-8140(02)00409-7 (Pubitemid 36695102)
8. P. F. O'Brien, B. A. Gillies, M. Schwartz, C. Young, and P. Davey, " Radiosurgery with unflattened 6-MV photon beams.," Med. Phys. 0094-2405 18, 519-521 (1991). 10.1118/1.596656
9. K. E. Sixel and B. A. Faddegon, " Calculation of x-ray spectra for radiosurgical beams.," Med. Phys. 0094-2405 22, 1657-1661 (1995). 10.1118/1.597426
10. S. Zefkili, C. Kappas, and J. C. Rosenwald, " On-axis and off-axis primary dose component in high energy photon beams.," Med. Phys. 0094-2405 21, 799-808 (1994). 10.1118/1.597325 (Pubitemid 24188130)
11. T. C. Zhu and B. E. Bjarngard, " The fraction of photons undergoing head scatter in x-ray beams.," Phys. Med. Biol. 0031-9155 40, 1127-1134 (1995). 10.1088/0031-9155/40/6/011
12. A. Brahme, T. Kraepelien, and H. Svensson, " Electron and photon beams from a 50 MeV racetrack microtron.," Acta Radiol. Oncol. 0349-652X 19, 305-319 (1980). 10.3109/02841868009130169 (Pubitemid 11197654)
13. M. Karlsson, H. Nystrom, and H. Svensson, " Photon beam characteristics on the MM50 racetrack microtron and a new approach for beam quality determination.," Med. Phys. 0094-2405 20, 143-149 (1993). 10.1118/1.597162 (Pubitemid 23069869)
14. M. Karlsson and B. Zackrisson, " Exploration of new treatment modalities offered by high energy (up to 50 MeV) electrons and photons.," Radiother. Oncol. 0167-8140 43, 303-309 (1997). 10.1016/S0167-8140(97)00077-7 (Pubitemid 27248477)
15. A. Sätherberg and M. Karlsson, " Calculation of photon energy and dose distributions in a 50 MV scanned photon beam for different target configurations and scan patterns.," Med. Phys. 0094-2405 25, 236-240 (1998). 10.1118/1.598186 (Pubitemid 28099857)
16. F. Araki, " Monte Carlo study of a Cyberknife stereotactic radiosurgery system.," Med. Phys. 0094-2405 33, 2955-2963 (2006). 10.1118/1.2219774 (Pubitemid 44154569)
17. S. Dieterich and T. Pawlicki, " Cyberknife image-guided delivery and quality assurance.," Int. J. Radiat. Oncol., Biol., Phys. 0360-3016 71, S126-S130 (2008). 10.1016/j.ijrobp.2007.08.081
18. R. Jeraj, T. R. Mackie, J. Balog, G. Olivera, D. Pearson, J. Kapatoes, K. Ruchala, and P. Reckwerdt, " Radiation characteristics of helical tomotherapy.," Med. Phys. 0094-2405 31, 396-404 (2004). 10.1118/1.1639148 (Pubitemid 38235410)
19. T. R. Mackie, T. Holmes, S. Swerdloff, P. Reckwerdt, J. O. Deasy, J. Yang, B. Paliwal, and T. Kinsella, " Tomotherapy: A new concept for the delivery of dynamic conformal radiotherapy.," Med. Phys. 0094-2405 20, 1709-1719 (1993). 10.1118/1.596958 (Pubitemid 24001191)
20. J. Cashmore, " The characterization of unflattened photon beams from a 6 MV linear accelerator.," Phys. Med. Biol. 0031-9155 53, 1933-1946 (2008). 10.1088/0031-9155/53/7/009 (Pubitemid 351570900)
21. G. Kragl, S. af Wetterstedt, B. Knausl, M. Lind, P. McCavana, T. Knoos, B. McClean, and D. Georg, " Dosimetric characteristics of 6 and 10MV unflattened photon beams.," Radiother. Oncol. 0167-8140 93, 141-146 (2009). 10.1016/j.radonc.2009.06.008
22. F. Pönisch, U. Titt, O. N. Vassiliev, S. F. Kry, and R. Mohan, " Properties of unflattened photon beams shaped by a multileaf collimator.," Med. Phys. 0094-2405 33, 1738-1746 (2006). 10.1118/1.2201149 (Pubitemid 43830262)
23. U. Titt, O. N. Vassiliev, F. Ponisch, L. Dong, H. Liu, and R. Mohan, " A flattening filter free photon treatment concept evaluation with Monte Carlo.," Med. Phys. 0094-2405 33, 1595-1602 (2006). 10.1118/1.2198327 (Pubitemid 43830248)
24. S. Stathakis, C. Esquivel, A. Gutierrez, C. R. Buckey, and N. Papanikolaou, " Treatment planning and delivery of IMRT using 6 and 18 MV photon beams without flattening filter.," Appl. Radiat. Isot. 0969-8043 67, 1629-1637 (2009). 10.1016/j.apradiso.2009.03.014
25. E. Tyner, B. McClean, P. McCavana, and S. af Wetterstedt, " Experimental investigation of the response of an a-Si EPID to an unflattened photon beam from an Elekta Precise linear accelerator.," Med. Phys. 0094-2405 36, 1318-1329 (2009). 10.1118/1.3089424
26. M. Lind, T. Knöös, C. Ceberg, E. Wieslander, B. McClean, and D. Georg, " Photon beam characteristics at the Monitor chamber level in a flattening filter free linac: A Monte Carlo study.," Radiother. Oncol. 0167-8140 92, S57 (2009). 10.1016/j.radonc.2009.03.010
27. J. Deng, T. Guerrero, C. M. Ma, and R. Nath, " Modeling 6 MV photon beams of a stereotactic radiosurgery system for Monte Carlo treatment planning.," Phys. Med. Biol. 0031-9155 49, 1689-1704 (2004). 10.1088/0031-9155/49/9/007 (Pubitemid 38678708)
28. B. A. Faddegon, C. K. Ross, and D. W. Rogers, " Angular distribution of bremsstrahlung from 15-MeV electrons incident on thick targets of Be, Al, and Pb.," Med. Phys. 0094-2405 18, 727-739 (1991). 10.1118/1.596667
29. A. Piermattei, G. Arcovito, L. Azario, C. Bacci, L. Bianciardi, E. De Sapio, and C. Giacco, " A study of quality of bremsstrahlung spectra reconstructed from transmission measurements.," Med. Phys. 0094-2405 17, 227-233 (1990). 10.1118/1.596567 (Pubitemid 20140140)
30. A. Mesbahi and F. S. Nejad, " Monte Carlo study on a flattening filter-free 18-MV photon beam of a medical linear accelerator.," Radiat. Med. 0288-2043 26, 331-336 (2008). 10.1007/s11604-008-0234-y
31. A. Tsechanski, Y. Krutman, and S. Faermann, " On the existence of low-energy photons (<150 keV) in the unflattened x-ray beam from an ordinary radiotherapeutic target in a medical linear accelerator.," Phys. Med. Biol. 0031-9155 50, 5629-5639 (2005). 10.1088/0031-9155/50/23/015 (Pubitemid 41750445)
32. M. Dalaryd, G. Kragl, C. Ceberg, D. Georg, T. Knöös, B. McClean, E. Wieslander, and S. af Wetterstedt, " A Monte Carlo study of a flattening-filter free linear accelerator verified with measurements.," Phys. Med. Biol. 0031-9155 55, 7333-7344 (2010). 10.1088/0031-9155/55/23/010
33. A. Mesbahi, " Dosimetric characteristics of unflattened 6 MV photon beams of a clinical linear accelerator: A Monte Carlo study.," Appl. Radiat. Isot. 0969-8043 65, 1029-1036 (2007). 10.1016/j.apradiso.2007.04.023 (Pubitemid 47238263)
34. P. L. Petti, M. S. Goodman, J. M. Sisterson, P. J. Biggs, T. A. Gabriel, and R. Mohan, " Sources of electron contamination for the Clinac-35 25-MV photon beam.," Med. Phys. 0094-2405 10, 856-861 (1983). 10.1118/1.595348 (Pubitemid 14216135)
35. P. J. Biggs and M. D. Russell, " An investigation into the presence of secondary electrons in megavoltage photon beams.," Phys. Med. Biol. 0031-9155 28, 1033-1043 (1983). 10.1088/0031-9155/28/9/003
36. D. Sheikh-Bagheri and D. W. O. Rogers, " Monte Carlo calculation of nine megavoltage photon beam spectra using the BEAM code.," Med. Phys. 0094-2405 29, 391-402 (2002). 10.1118/1.1445413 (Pubitemid 34241162)
37. H. Beauvais, A. Bridier, and A. Dutreix, " Characteristics of contamination electrons in high energy photon beams.," Radiother. Oncol. 0167-8140 29, 308-316 (1993). 10.1016/0167-8140(93)90149-3 (Pubitemid 24025352)
38. R. Sjögren and M. Karlsson, " Electron contamination in clinical high energy photon beams.," Med. Phys. 0094-2405 23, 1873-1881 (1996). 10.1118/1.597750 (Pubitemid 26394088)
39. D. Georg, F. Julia, E. Briot, D. Huyskens, U. Wolff, and A. Dutreix, " Dosimetric comparison of an integrated multileaf-collimator versus a conventional collimator.," Phys. Med. Biol. 0031-9155 42, 2285-2303 (1997). 10.1088/0031-9155/42/11/020 (Pubitemid 27512544)
40. E. L. Chaney, T. J. Cullip, and T. A. Gabriel, " A Monte Carlo study of accelerator head scatter.," Med. Phys. 0094-2405 21, 1383-1390 (1994). 10.1118/1.597194 (Pubitemid 24307954)
41. X. R. Zhu, Y. Kang, and M. T. Gillin, " Measurements of in-air output ratios for a linear accelerator with and without the flattening filter.," Med. Phys. 0094-2405 33, 3723-3733 (2006). 10.1118/1.2349695 (Pubitemid 44505098)
42. A. Ahnesjö, " Analytic modeling of photon scatter from flattening filters in photon therapy beams.," Med. Phys. 0094-2405 21, 1227-1235 (1994). 10.1118/1.597205 (Pubitemid 24268793)
43. J. Byrne and G. Lambert, " A generalized extension to the Hounsell-Wilkinson head scatter model.," Phys. Med. Biol. 0031-9155 49, N277-N285 (2004). 10.1088/0031-9155/49/17/N02 (Pubitemid 39243004)
44. A. R. Hounsell and J. M. Wilkinson, " Head scatter modeling for irregular field shaping and beam intensity modulation.," Phys. Med. Biol. 0031-9155 42, 1737-1749 (1997). 10.1088/0031-9155/42/9/006 (Pubitemid 27400359)
45. J. Olofsson, T. Nyholm, D. Georg, A. Ahnesjo, and M. Karlsson, " Evaluation of uncertainty predictions and dose output for model-based dose calculations for megavoltage photon beams.," Med. Phys. 0094-2405 33, 2548-2556 (2006). 10.1118/1.2207316 (Pubitemid 43967244)
46. I. Fotina, P. Winkler, T. Kunzler, J. Reiterer, I. Simmat, and D. Georg, " Advanced kernel methods vs. Monte Carlo-based dose calculation for high energy photon beams.," Radiother. Oncol. 0167-8140 93, 645-653 (2009). 10.1016/j.radonc.2009.10.013
47. E. J. Hall, " Intensity-modulated radiation therapy, protons, and the risk of second cancers.," Int. J. Radiat. Oncol., Biol., Phys. 0360-3016 65, 1-7 (2006). 10.1016/j.ijrobp.2006.01.027
48. F. d'Errico, M. Luszik-Bhadra, R. Nath, B. R. Siebert, and U. Wolf, " Depth dose-equivalent and effective energies of photoneutrons generated by 6-18 MV X-ray beams for radiotherapy.," Health Phys. 0017-9078 80, 4-11 (2001). 10.1097/00004032-200101000-00003 (Pubitemid 32009607)
49. A. Zanini, E. Durisi, F. Fasolo, C. Ongaro, L. Visca, U. Nastasi, K. W. Burn, G. Scielzo, J. O. Adler, J. R. M. Annand, and G. Rosner, " Monte Carlo simulation of the photoneutron field in linac radiotherapy treatments with different collimation systems.," Phys. Med. Biol. 0031-9155 49, 571-582 (2004). 10.1088/0031-9155/49/4/008 (Pubitemid 38255939)
50. J. Becker, E. Brunckhorst, and R. Schmidt, " Photoneutron production of a Siemens Primus linear accelerator studied by Monte Carlo methods and a paired magnesium and boron coated magnesium ionization chamber system.," Phys. Med. Biol. 0031-9155 52, 6375-6387 (2007). 10.1088/0031-9155/52/21/002 (Pubitemid 350093168)
51. D. S. Followill, M. S. Stovall, S. F. Kry, and G. S. Ibbott, " Neutron source strength measurements for Varian, Siemens, Elekta, and General Electric linear accelerators.," J. Appl. Clin. Med. Phys. 1526-9914 4, 189-194 (2003). 10.1120/1.1571671
52. R. M. Howell, S. F. Kry, E. Burgett, N. E. Hertel, and D. S. Followill, " Secondary neutron spectra from modern Varian, Siemens, and Elekta linacs with multileaf collimators.," Med. Phys. 0094-2405 36, 4027-4038 (2009). 10.1118/1.3159300
53. S. F. Kry, R. M. Howell, U. Titt, M. Salehpour, R. Mohan, and O. N. Vassiliev, " Energy spectra, sources, and shielding considerations for neutrons generated by a flattening filter-free Clinac.," Med. Phys. 0094-2405 35, 1906-1911 (2008). 10.1118/1.2905029 (Pubitemid 351614805)
54. S. F. Kry, U. Titt, F. Ponisch, O. N. Vassiliev, M. Salehpour, M. Gillin, and R. Mohan, " Reduced neutron production through use of a flattening-filter-free accelerator.," Int. J. Radiat. Oncol., Biol., Phys. 0360-3016 68, 1260-1264 (2007). 10.1016/j.ijrobp.2007.04.002 (Pubitemid 47048591)
55. A. Mesbahi, " A Monte Carlo study on neutron and electron contamination of an unflattened 18-MV photon beam.," Appl. Radiat. Isot. 0969-8043 67, 55-60 (2009). 10.1016/j.apradiso.2008.07.013
56. T. Wiezorek, D. Georg, M. Schwedas, H. Salz, and T. G. Wendt, " Experimental determination of peripheral photon dose components for different IMRT techniques and linear accelerators.," Z. Med. Phys. 0939-3889 19, 120-128 (2009). 10.1016/j.zemedi.2009.01.008
57. D. S. Followill, F. Nusslin, and C. G. Orton, " Point/counterpoint. IMRT should not be administered at photon energies greater than 10 MV.," Med. Phys. 0094-2405 34, 1877-1879 (2007). 10.1118/1.2734751 (Pubitemid 47055719)
58. E. Sterpin, F. Salvat, R. Cravens, K. Ruchala, G. H. Olivera, and S. Vynckier, " Monte Carlo simulation of helical tomotherapy with PENELOPE.," Phys. Med. Biol. 0031-9155 53, 2161-2180 (2008). 10.1088/0031-9155/53/8/011 (Pubitemid 351605991)
59. O. N. Vassiliev, U. Titt, F. Pönisch, S. F. Kry, R. Mohan, and M. T. Gillin, " Dosimetric properties of photon beams from a flattening filter free clinical accelerator.," Phys. Med. Biol. 0031-9155 51, 1907-1917 (2006). 10.1088/0031-9155/51/7/019
60. T. C. Zhu, A. Ahnesjo, K. L. Lam, X. A. Li, C. -M. C. Ma, J. R. Palta, M. B. Sharpe, B. Thomadsen, and R. C. Tailor, " Report of AAPM Therapy Physics Committee Task Group 74: In-air output ratio, Sc, for megavoltage photon beams.," Med. Phys. 0094-2405 36, 5261-5291 (2009). 10.1118/1.3227367
61. D. Georg, J. Olofsson, T. Kunzler, and M. Karlsson, " On empirical methods to determine scatter factors for irregular MLC shaped beams.," Med. Phys. 0094-2405 31, 2222-2229 (2004). 10.1118/1.1767695 (Pubitemid 39079714)
62. I. J. Das, G. X. Ding, and A. Ahnesjo, " Small fields: Nonequilibrium radiation dosimetry.," Med. Phys. 0094-2405 35, 206-215 (2008). 10.1118/1.2815356
63. R. Alfonso, P. Andreo, R. Capote, M. S. Huq, W. Kilby, P. Kjall, T. R. Mackie, H. Palmans, K. Rosser, J. Seuntjens, W. Ullrich, and S. Vatnitsky, " A new formalism for reference dosimetry of small and nonstandard fields.," Med. Phys. 0094-2405 35, 5179-5186 (2008). 10.1118/1.3005481
64. M. M. Aspradakis, G. D. Lambert, and A. Steele, " Elements of commissioning step-and-shoot IMRT: Delivery equipment and planning system issues posed by small segment dimensions and small monitor units.," Med. Dosim. 0739-0211 30, 233-242 (2005). 10.1016/j.meddos.2005.08.005 (Pubitemid 41579023)
65. J. Li and T. C. Zhu, " Measurement of in-air output ratios using different miniphantom materials.," Phys. Med. Biol. 0031-9155 51, 3819-3834 (2006). 10.1088/0031-9155/51/15/015 (Pubitemid 44131367)
66. C. McKerracher and D. I. Thwaites, " Head scatter factors for small MV photon fields. Part I: A comparison of phantom types and methodologies., " Radiother. Oncol. 0167-8140 85, 277-285 (2007). (Pubitemid 350161010)
67. C. McKerracher and D. I. Thwaites, " Head scatter factors for small MV photon fields. Part II: The effects of source size and detector.," Radiother. Oncol. 0167-8140 85, 286-291 (2007). (Pubitemid 350161011)
68. F. Sánchez-Doblado, P. Andreo, R. Capote, A. Leal, M. Perucha, R. Arrans, L. Nunez, E. Mainegra, J. I. Lagares, and E. Carrasco, " Ionization chamber dosimetry of small photon fields: A Monte Carlo study on stopping-power ratios for radiosurgery and IMRT beams.," Phys. Med. Biol. 0031-9155 48, 2081-2099 (2003). 10.1088/0031-9155/48/14/304 (Pubitemid 36926702)
69. F. Sánchez-Doblado, G. H. Hartmann, J. Pena, R. Capote, M. Paiusco, B. Rhein, A. Leal, and J. I. Lagares, " Uncertainty estimation in intensity-modulated radiotherapy absolute dosimetry verification.," Int. J. Radiat. Oncol., Biol., Phys. 0360-3016 68, 301-310 (2007). 10.1016/j.ijrobp. 2006.11.056 (Pubitemid 46613847)
70. P. Storchi and J. J. van Gasteren, " A table of phantom scatter factors of photon beams as a function of the quality index and field size.," Phys. Med. Biol. 0031-9155 41, 563-571 (1996). 10.1088/0031-9155/ 41/3/016 (Pubitemid 26098991)
71. D. Georg, G. Kragl, S. af Wetterstedt, P. McCavana, B. McClean, and T. Knoos, " Photon beam quality variations of a flattening filter free linear accelerator.," Med. Phys. 0094-2405 37, 49-53 (2010). 10.1118/1.3264617
72. O. N. Vassiliev, U. Titt, S. F. Kry, F. Pönisch, M. T. Gillin, and R. Mohan, " Monte Carlo study of photon fields from a flattening filter-free clinical accelerator.," Med. Phys. 0094-2405 33, 820-827 (2006). 10.1118/1.2174720
73. A. Sätherberg, M. Karlsson, and M. Karlsson, " Theoretical and experimental determination of phantom scatter factors for photon fields with different radial energy variation.," Phys. Med. Biol. 0031-9155 41, 2687-2694 (1996). 10.1088/0031-9155/41/12/008 (Pubitemid 26412564)
74. J. L. Venselaar, S. Heukelom, H. N. Jager, B. J. Mijnheer, J. J. van Gasteren, H. J. van Kleffens, R. van der Laarse, and C. F. Westermann, " Is there a need for a revised table of equivalent square fields for the determination of phantom scatter correction factors?," Phys. Med. Biol. 0031-9155 42, 2369-2381 (1997). 10.1088/0031-9155/42/12/005 (Pubitemid 28015562)
75. H. Nystrom and M. Karlsson, " Photon beam quality specification by narrow-beam transmission measurements.," Phys. Med. Biol. 0031-9155 39, 1231-1245 (1994). 10.1088/0031-9155/39/8/004 (Pubitemid 24246747)
76. J. J. M. van Gasteren, S. Heukelom, H. N. Jager, B. J. Mijnheer, R. van der Laarse, H. J. van Kleffens, J. L. M. Venselaar, and C. F. Westermann, " Determination and use of scatter correction factors of arbitrarily shaped fields with a symmetrical collimator setting.," Netherlands Commission on Radiation Therapy, NCS Report No. 12, 1998.
77. J. Olofsson, T. Nyholm, A. Ahnesjo, and M. Karlsson, " Optimization of photon beam flatness for radiation therapy.," Phys. Med. Biol. 0031-9155 52, 1735-1746 (2007). 10.1088/0031-9155/52/6/013 (Pubitemid 46646378)
78. U. Titt, O. N. Vassiliev, F. Ponisch, S. F. Kry, and R. Mohan, " Monte Carlo study of backscatter in a flattening filter free clinical accelerator.," Med. Phys. 0094-2405 33, 3270-3273 (2006). 10.1118/1.2229430 (Pubitemid 44327429)
79. C. F. Chuang, D. A. Larson, A. Zytkovicz, V. Smith, and P. L. Petti, " Peripheral dose measurement for CyberKnife radiosurgery with upgraded linac shielding.," Med. Phys. 0094-2405 35, 1494-1496 (2008). 10.1118/1.2889620 (Pubitemid 351457517)
80. S. F. Kry, O. N. Vassiliev, and R. Mohan, " Out-of-field photon dose following removal of the flattening filter from a medical accelerator.," Phys. Med. Biol. 0031-9155 55, 2155-2166 (2010). 10.1088/0031-9155/55/8/003
81. D. B. Mansur, E. E. Klein, and B. P. Maserang, " Measured peripheral dose in pediatric radiation therapy: A comparison of intensity-modulated and conformal techniques.," Radiother. Oncol. 0167-8140 82, 179-184 (2007). 10.1016/j.radonc.2007.01.002 (Pubitemid 46275138)
82. G. Kragl, F. Baier, S. Lutz, D. Albrich, M. Dalaryd, B. Kroupa, T. Wiezorek, T. Knöös, and D. Georg, " Flattening filter free beams in SBRT and IMRT: Dosimetric assessment of peripheral doses.," Z. Med. Phys. 0939-3889 (in press).
83. J. Cashmore, M. Ramtohul, and D. Ford, " Lowering whole-body radiation doses in pediatric intensity-modulated radiotherapy through the use of unflattened photon beams.," Int. J. Radiat. Oncol., Biol., Phys. 0360-3016 (in press).
84. P. R. Almond, P. J. Biggs, B. M. Coursey, W. F. Hanson, M. S. Huq, R. Nath, and D. W. Rogers, " AAPM's TG-51 protocol for clinical reference dosimetry of high-energy photon and electron beams.," Med. Phys. 0094-2405 26, 1847-1870 (1999). 10.1118/1.598691 (Pubitemid 29442268)
85. IAEA, " Absorbed dose determination in external beam radiotherapy: An international code of practice for dosimetry based on standards of absorbed dose to water.," IAEA Technical Reports Series No. TRS-398 (Vienna, Austria, 2000).
86. J. P. Seuntjens, C. K. Ross, K. R. Shortt, and D. W. Rogers, " Absorbed-dose beam quality conversion factors for cylindrical chambers in high energy photon beams.," Med. Phys. 0094-2405 27, 2763-2779 (2000). 10.1118/1.1328081 (Pubitemid 32063456)
87. O. A. Sauer, " Determination of the quality index (Q) for photon beams at arbitrary field sizes.," Med. Phys. 0094-2405 36, 4168-4172 (2009). 10.1118/1.3197062
88. G. Xiong and D. W. Rogers, " Relationship between %dd(10)x and stopping-power ratios for flattening filter free accelerators: A Monte Carlo study.," Med. Phys. 0094-2405 35, 2104-2109 (2008). 10.1118/1.2905028 (Pubitemid 351614825)
89. C. Ceberg, S. Johnsson, M. Lind, and T. Knoos, " Prediction of stopping-power ratios in flattening-filter free beams.," Med. Phys. 0094-2405 37, 1164-1168 (2010). 10.1118/1.3314074
90. R. Jeraj, T. R. Mackie, J. Balog, and G. Olivera, " Dose calibration of nonconventional treatment systems applied to helical tomotherapy.," Med. Phys. 0094-2405 32, 570-577 (2005). 10.1118/1.1855015 (Pubitemid 40322339)
91. S. D. Thomas, M. Mackenzie, D. W. O. Rogers, and B. G. Fallone, " A Monte Carlo derived TG-51 equivalent calibration for helical tomotherapy.," Med. Phys. 0094-2405 32, 1346-1353 (2005). 10.1118/1.1897084 (Pubitemid 40695778)
92. S. Flampouri, H. A. McNair, E. M. Donovan, P. M. Evans, M. Partridge, F. Verhaegen, and C. M. Nutting, " Initial patient imaging with an optimised radiotherapy beam for portal imaging.," Radiother. Oncol. 0167-8140 76, 63-71 (2005). 10.1016/j.radonc.2005.04.006 (Pubitemid 41096517)
93. A. Mans, P. Remeijer, I. Olaciregui-Ruiz, M. Wendling, J. -J. Sonke, B. Mijnheer, M. van Herk, and J. C. Stroom, " 3D Dosimetric verification of volumetric-modulated arc therapy by portal dosimetry.," Radiother. Oncol. 0167-8140 94, 181-187 (2010). 10.1016/j.radonc.2009.12.020
94. B. A. Faddegon, M. Aubin, A. Bani-Hashemi, B. Gangadharan, A. R. Gottschalk, O. Morin, D. Sawkey, V. Wu, and S. S. Yom, " Comparison of patient megavoltage cone beam CT images acquired with an unflattened beam from a carbon target and a flattened treatment beam.," Med. Phys. 0094-2405 37, 1737-1741 (2010). 10.1118/1.3359822
95. B. A. Faddegon, V. Wu, J. Pouliot, B. Gangadharan, and A. Bani-Hashemi, " Low dose megavoltage cone beam computed tomography with an unflattened 4 MV beam from a carbon target.," Med. Phys. 0094-2405 35, 5777-5786 (2008). 10.1118/1.3013571
96. D. Georg, K. Dieckmann, J. Bogner, M. Zehetmayer, and R. Potter, " Impact of a micromultileaf collimator on stereotactic radiotherapy of uveal melanoma.," Int. J. Radiat. Oncol., Biol., Phys. 0360-3016 55, 881-891 (2003). 10.1016/S0360-3016(02)04119-6 (Pubitemid 36286990)
97. M. Brada and R. Laing, " Radiosurgery/stereotactic external beam radiotherapy for malignant brain tumours: The Royal Marsden Hospital experience.," Recent Results Cancer Res. 0080-0015 135, 91-104 (1994).
98. K. Dieckmann, J. Bogner, D. Georg, M. Zehetmayer, G. Kren, and R. Potter, " A linac-based stereotactic irradiation technique of uveal melanoma.," Radiother. Oncol. 0167-8140 61, 49-56 (2001). 10.1016/S0167-8140(01)00413-3 (Pubitemid 32913461)
99. K. Dieckmann, D. Georg, M. Zehetmayer, J. Bogner, M. Georgopoulos, and R. Potter, " LINAC based stereotactic radiotherapy of uveal melanoma: 4 years clinical experience.," Radiother. Oncol. 0167-8140 67, 199-206 (2003). 10.1016/S0167-8140(02)00345-6 (Pubitemid 36695098)
100. M. Partridge, A. Tree, J. Brock, H. McNair, E. Fernandez, N. Panakis, and M. Brada, " Improvement in tumour control probability with active breathing control and dose escalation: A modeling study.," Radiother. Oncol. 0167-8140 91, 325-329 (2009). 10.1016/j.radonc.2009.03.017
101. M. Stock, K. Kontrisova, K. Dieckmann, J. Bogner, R. Poetter, and D. Georg, " Development and application of a real-time monitoring and feedback system for deep inspiration breath hold based on external marker tracking.," Med. Phys. 0094-2405 33, 2868-2877 (2006). 10.1118/1.2219775 (Pubitemid 44154558)
102. J. Hanley, M. M. Debois, D. Mah, G. S. Mageras, A. Raben, K. Rosenzweig, B. Mychalczak, L. H. Schwartz, P. J. Gloeggler, W. Lutz, C. C. Ling, S. A. Leibel, Z. Fuks, and G. J. Kutcher, " Deep inspiration breath-hold technique for lung tumors: The potential value of target immobilization and reduced lung density in dose escalation.," Int. J. Radiat. Oncol., Biol., Phys. 0360-3016 45, 603-611 (1999). 10.1016/S0360-3016(99)00154-6 (Pubitemid 29462639)
103. O. N. Vassiliev, S. F. Kry, J. Y. Chang, P. A. Balter, U. Titt, and R. Mohan, " Stereotactic radiotherapy for lung cancer using a flattening filter free Clinac.," J. Appl. Clin. Med. Phys. 1526-9914 10, 14-21 (2009). 10.1120/jacmp.v10i1.2880
104. W. Fu, J. Dai, Y. Hu, D. Han, and Y. Song, " Delivery time comparison for intensity-modulated radiation therapy with/without flattening filter: A planning study.," Phys. Med. Biol. 0031-9155 49, 1535-1547 (2004). 10.1088/0031-9155/49/8/011 (Pubitemid 38578502)
105. O. N. Vassiliev, S. F. Kry, D. A. Kuban, M. Salehpour, R. Mohan, and U. Titt, " Treatment-planning study of prostate cancer intensity-modulated radiotherapy with a Varian Clinac operated without a flattening filter.," Int. J. Radiat. Oncol., Biol., Phys. 0360-3016 68, 1567-1571 (2007). 10.1016/j.ijrobp.2007.04.025 (Pubitemid 47176832)
106. A. Bertelsen, C. R. Hansen, J. Johansen, and C. Brink, " Single arc volumetric modulated arc therapy of head and neck cancer.," Radiother. Oncol. 0167-8140 95, 142-148 (2010). 10.1016/j.radonc.2010.01.011
107. J. Hrbacek, S. Lang, and S. Klock, " Commissioning of photon beams of a flattening filter-free linear accelerator and the accuracy of beam modeling using an anisotropic analytical algorithm.," Int. J. Radiat. Oncol., Biol., Phys. 0360-3016 (in press).
108. P. Ost, B. Speleers, G. De Meerleer, W. De Neve, V. Fonteyne, G. Villeirs, and W. De Gersem, " Volumetric arc therapy and intensity-modulated radiotherapy for primary prostate radiotherapy with simultaneous integrated boost to intraprostatic lesion with 6 and 18 MV: A planning comparison study.," Int. J. Radiat. Oncol., Biol., Phys. 0360-3016 79, 920-926 (2011). 10.1016/j.ijrobp.2010.04.025
109. K. Otto, " Volumetric modulated arc therapy: IMRT in a single gantry arc.," Med. Phys. 0094-2405 35, 310-317 (2008). 10.1118/1.2818738
110. M. Rao, W. Yang, F. Chen, K. Sheng, J. Ye, V. Mehta, D. Shepard, and D. Cao, " Comparison of Elekta VMAT with helical tomotherapy and fixed field IMRT: Plan quality, delivery efficiency and accuracy.," Med. Phys. 0094-2405 37, 1350-1359 (2010). 10.1118/1.3326965
111. E. Gershkevitsh, R. Schmidt, G. Velez, D. Miller, E. Korf, F. Yip, S. Wanwilairat, and S. Vatnitsky, " Dosimetric verification of radiotherapy treatment planning systems: Results of IAEA pilot study.," Radiother. Oncol. 0167-8140 89, 338-346 (2008). 10.1016/j.radonc.2008.07.007
112. S. F. Kry, R. M. Howell, J. Polf, R. Mohan, and O. N. Vassiliev, " Treatment vault shielding for a flattening filter-free medical linear accelerator.," Phys. Med. Biol. 0031-9155 54, 1265-1273 (2009). 10.1088/0031-9155/54/5/011
113. O. N. Vassiliev, U. Titt, S. F. Kry, R. Mohan, and M. T. Gillin, " Radiation safety survey on a flattening filter-free medical accelerator.," Radiat. Prot. Dosim. 0144-8420 124, 187-190 (2007). 10.1093/rpd/ncm179
114. J. J. W. Lagendijk, B. W. Raaymakers, A. J. E. Raaijmakers, J. Overweg, K. J. Brown, E. M. Kerkhof, R. W. van der Put, B. Hardemark, M. van Vulpen, and U. A. van der Heide, " MRI/linac integration.," Radiother. Oncol. 0167-8140 86, 25-29 (2008). 10.1016/j.radonc.2007.10.034
115. E. Pantelis, A. Moutsatsos, K. Zourari, W. Kilby, C. Antypas, P. Papagiannis, P. Karaiskos, E. Georgiou, and L. Sakelliou, " On the implementation of a recently proposed dosimetric formalism to a robotic radiosurgery system.," Med. Phys. 0094-2405 37, 2369-2379 (2010). 10.1118/1.3404289
116. K. E. Rosser and J. L. Bedford, " Application of a new dosimetry formalism to volumetric modulated arc therapy (VMAT).," Phys. Med. Biol. 0031-9155 54, 7045-7061 (2009). 10.1088/0031-9155/54/23/001
117. A. van der Kogel, in Basic Clinical Radiobiology, edited by, M. Joiner, and, A. van der Kogel, (Hodder Arnold, London, 2009), Chap.
118. T. Kim, L. Zhu, T. -S. Suh, S. Geneser, B. Meng, and L. Xing, " Inverse planning for IMRT with nonuniform beam profiles using total-variation regularization (TVR).," Med. Phys. 0094-2405 38, 57-66 (2011). 10.1118/1.3521465