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Implementation and commissioning of an integrated micro-CT/RT system with computerized independent jaw collimation
2.J. Wong, E. Armour, P. Kazanzides, I. Iordachita, E. Tryggestad, H. Deng, M. Matinfar, C. Kennedy, Z. Liu, T. Chan, O. Gray, F. Verhaegen, T. McNutt, E. Ford, and T. L. DeWeese, “High-resolution, small animal radiation research platform with x-ray tomographic guidance capabilities,” Int. J. Radiat. Oncol., Biol., Phys. 71, 1591–1599 (2008).
3.M. Matinfar, E. Ford, I. Iordachita, J. Wong, and P. Kazanzides, “Image-guided small animal radiation research platform: Calibration of treatment beam alignment,” Phys. Med. Biol. 54, 891–905 (2009).
4.R. Clarkson, P. E. Lindsay, S. Ansell, G. Wilson, S. Jelveh, R. P. Hill, and D. A. Jaffray, “Characterization of image quality and image-guidance performance of a preclinical microirradiator,” Med. Phys. 38, 845–856 (2011).
5.P. V. Granton, M. Podesta, G. Landry, S. Nijsten, G. Bootsma, and F. Verhaegen, “A combined dose calculation and verification method for a small animal precision irradiator based on onboard imaging,” Med. Phys. 39, 4155–4166 (2012).
6.R. Pidikiti, S. Stojadinovic, M. Speiser, K. H. Song, F. Hager, D. Saha, and T. D. Solberg, “Dosimetric characterization of an image-guided stereotactic small animal irradiator,” Phys. Med. Biol. 56, 2585–2599 (2011).
7.S. Stojadinovic, D. S. Low, M. Vicic, S. Mutic, J. O. Deasy, A. J. Hope, P. J. Parikh, and P. W. Grigsby, “Progress toward a microradiation therapy small animal conformal irradiator,” Med. Phys. 33, 3834–3845 (2006).
8.S. Stojadinovic, D. A. Low, A. J. Hope, M. Vicic, J. O. Deasy, J. Cui, D. Khullar, P. J. Parikh, K. T. Malinowski, E. W. Izaguirre, S. Mutic, and P. W. Grigsby, “MicroRT—Small animal conformal irradiator,” Med. Phys. 34, 4706–4716 (2007).
9.H. Zhou, M. Rodriguez, F. van den Haak, G. Nelson, R. Jogani, J. Xu, X. Zhu, Y. Xian, P. T. Tran, D. W. Felsher, P. J. Keall, and E. E. Graves, “Development of a micro-computed tomography-based image-guided conformal radiotherapy system for small animals,” Int. J. Radiat. Oncol., Biol., Phys. 78, 297–305 (2010).
10.E. E. Graves, H. Zhou, R. Chatterjee, P. J. Keall, S. S. Gambhir, C. H. Contag, and A. L. Boyer, “Design and evaluation of a variable aperture collimator for conformal radiotherapy of small animals using a microCT scanner,” Med. Phys. 34, 4359–4367 (2007).
11.M. Bazalova, H. Zhou, P. J. Keall, and E. E. Graves, “Kilovoltage beam Monte Carlo dose calculations in submillimeter voxels for small animal radiotherapy,” Med. Phys. 36, 4991–4999 (2009).
12.M. Rodriguez, H. Zhou, P. Keall, and E. Graves, “Commissioning of a novel microCT/RT system for small animal conformal radiotherapy,” Phys. Med. Biol. 54, 3727–3740 (2009).
13.J. R. Dai and Y. M. Hu, “Intensity-modulation radiotherapy using independent collimator: Algorithm study,” Med. Phys. 26, 2562–2570 (1999).
14.J. W. Anderson, R. Symonds-Tayler, and S. Webb, “Investigating the fundamentals of IMRT decomposition using ten simple collimator models,” Phys. Med. Biol. 51, 2225–2236 (2006).
15.M. A. Bahri, G. Warnock, A. Plenevaux, P. Choquet, A. Constantinesco, E. Salmon, A. Luxen, and A. Seret, “Performance evaluation of the general electric eXplore CT 120 micro-CT using the vmCT phantom,” Nucl. Instrum. Methods Phys. Res. A 648, S181–S185 (2011).
16.L. Y. Du, J. Umoh, H. N. Nikolov, S. I. Pollmann, T.-Y. Lee, and D. W. Holdsworth, “A quality assurance phantom for the performance evaluation of volumetric micro-CT systems,” Phys. Med. Biol. 52, 7087–7108 (2007).
17.S. Devic, J. Seuntjens, G. Hegyi, E. B. Podgorsak, C. G. Soares, A. S. Kirov, I. Ali, J. F. Williamson, and A. Elizondo, “Dosimetric properties of improved GafChromic films for seven different digitizers,” Med. Phys. 31, 2392–2401 (2004).
18.S. Devic, J. Seuntjens, E. Sham, E. B. Podgorsak, C. R. Schmidtlein, A. S. Kirov, and C. G. Soares, “Precise radiochromic film dosimetry using a flat-bed document scanner,” Med. Phys. 32, 2245–2253 (2005).
19.T. J. McCaw, J. A. Micka, and L. A. Dewerd, “Characterizing the marker-dye correction for Gafchromic(®) EBT2 film: A comparison of three analysis methods,” Med. Phys. 38, 5771–5777 (2011).
20.I. Kawrakow and D. W. O. Rogers, “The EGSnrc code system: Monte Carlo simulation of electron and photon transport,” NRCC Report No. PIRS-701 (National Research Council of Canada, Ottawa, 2006).
21.I. Kawrakow, “Accurate condensed history Monte Carlo simulation of electron transport. I. EGSnrc, the new EGS4 version,” Med. Phys. 27, 485–498 (2000).
22.D. W. Rogers, B. A. Faddegon, G. X. Ding, C. M. Ma, J. We, and T. R. Mackie, “BEAM: A Monte Carlo code to simulate radiotherapy treatment units,” Med. Phys. 22, 503–524 (1995).
23.B. R. B. Walters, I. Kawrakow, and D. W. O. Rogers, “DOSXYZnrc users manual,” NRCC Report No. PIRS-794 rev B (National Research Council of Canada, Ottawa, 2007).
24.M. Bazalova and E. E. Graves, “The importance of tissue segmentation for dose calculations for kilovoltage radiation therapy,” Med. Phys. 38, 3039–3049 (2011).
25.A. R. Motomura, M. Bazalova, H. Zhou, P. J. Keall, and E. E. Graves, “Investigation of the effects of treatment planning variables in small animal radiotherapy dose distributions,” Med. Phys. 37, 590–599 (2010).
26.J. C. L. Chow, M. K. K. Leung, P. E. Lindsay, and D. A. Jaffray, “Dosimetric variation due to the photon beam energy in the small-animal irradiation: A Monte Carlo study,” Med. Phys. 37, 5322–5329 (2010).
28.I. J. Lee, J. Seong, C. G. Lee, Y. B. Kim, K. C. Keum, C. O. Suh, G. E. Kim, and J. Cho, “Early clinical experience and outcome of helical tomotherapy for multiple metastatic lesions,” Int. J. Radiat. Oncol., Biol., Phys. 73, 1517–1524 (2009).
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To design, construct, and commission a set of computer-controlled motorized jaws for a micro-CT/RT system to perform conformal image-guided small animal radiotherapy.
The authors designed and evaluated a system of custom-built motorized orthogonal jaws, which allows the delivery of off-axis rectangular fields on a GE eXplore CT 120 preclinical imaging system. The jaws in the x direction are independently driven, while the y-direction jaws are symmetric. All motors have backup encoders, verifying jaw positions. Mechanical performance of the jaws was characterized. Square beam profiles ranging from 2 × 2 to 60 × 60 mm2 were measured using EBT2 film in the center of a 70 × 70 × 22 mm3 solid water block. Similarly, absolute depth dose was measured in a solid water and EBT2 film stack 50 × 50 × 50 mm3. A calibrated Farmer ion chamber in a 70 × 70 × 20 mm3 solid water block was used to measure the output of three field sizes: 50 × 50, 40 × 40, and 30 × 30 mm2. Elliptical target plans were delivered to films to assess overall system performance. Respiratory-gated treatment was implemented on the system and initially proved using a simple sinusoidal motion phantom. All films were scanned on a flatbed scanner (Epson 1000XL) and converted to dose using a fitted calibration curve. A Monte Carlo beam model of the micro-CT with the jaws has been created using BEAMnrc for comparison with the measurements. An example image-guided partial lung irradiation in a rat is demonstrated.
The averaged random error of positioning each jaw is less than 0.1 mm. Relative output factors measured with the ion chamber agree with Monte Carlo simulations within 2%. Beam profiles and absolute depth dose curves measured from the films agree with simulations within measurement uncertainty. Respiratory-gated treatments applied to a phantom moving with a peak-to-peak amplitude of 5 mm showed improved beam penumbra (80%–20%) from 3.9 to 0.8 mm.
A set of computer-controlled motorized jaws for a micro-CT/RT system were constructed with position reliably better than a tenth of a millimeter. The hardware system is ready for image-guided conformal radiotherapy for small animals with capability of respiratory-gated delivery.
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