IJMPCERO  Vol.4 No.2 , May 2015
Assessment of Organ Dose by Direct and Indirect Measurements for a Wide Bore X-Ray Computed Tomography Unit That Used in Radiotherapy
The aim of this study was to investigate the organ doses of patients undergoing computed tomography (CT) examination using the wide bore General Electric (GE) “Light Speed RT” unit. The head, chest and pelvic regions of the Rando-phantom were scanned with 120 kV, 200 mA, and 2.5 mm slice thickness for helical and axial modes. Thermoluminescent Dosimeter (TLD) pairs were used for the dosimetry of 10 organs. TL-counts were converted to dose by using CTDIcenter dose on CT-phantom. For the calculation of the organ doses, the ImPACT software was utilized by entering CTDIair (100 mAs) in small and large field of view (26.43 and 21.17 mGy respectively). The in-field dose ranges in helical and axial modes were 64.3 - 38 mGy and 47.6 - 19.7 mGy in head, 48.3 - 14.1 mGy and 34.1 - 10 mGy in chest, 28.4 - 10.2 mGy and 21 - 8.5 mGy in pelvic, respectively. The organ doses from software and TLD were compared and tailored as the in-field and the out-field radiation. First results showed that the organ dose was relatively higher in the helical mode on both direct and indirect measurement. The in-field organ dose differences between TLD and software were seen. In helical and axial modes, the dose differences ranged from +1 to +13.3 and -8.3 to +9.6 mGy for head exam, +1.1 to +15.3 and +0.3 to +9.1 mGy for chest, and -21.7 to +1.9 and -15.5 to +1.8 mGy for pelvic. The availability of this program for organ dose calculations by measuring CTDIair value for CT device used in the radiotherapy would be considered valuable.

Cite this paper
Cakmak, E. , Tuncel, N. and Sindir, B. (2015) Assessment of Organ Dose by Direct and Indirect Measurements for a Wide Bore X-Ray Computed Tomography Unit That Used in Radiotherapy. International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, 4, 132-142. doi: 10.4236/ijmpcero.2015.42017.
[1]   American Association of Physicists in Medicine (2007) The Management of Imaging Dose during Image-Guided Radiotherapy, Report of the AAPM Task Group 75. Report No. 95. Medical Physicals, 34, 4041-4063.

[2]   American Association of Physicists in Medicine (2010) Comprehensive Methodology for the Evaluation of Radiation Dose in X-Ray Computed Tomography, Report of the AAPM Task Group 111. Report No. 111, New York.

[3]   United Nations Scientific Committee on Effects of Radiation Atomic Radiation (2000) UNSCEAR 2000 Report Vol. I Sources and Effects of Ionising Radiation Annex D: Medical Radiation Exposures. New York.

[4]   International Atomic Energy Agency (2001) Protection of Patients in Diagnostic and Intervention Radiology, Nuclear Medicine and Radiotherapy. Proceeding of International Conference, Malaga, 26-30 March 2001, Austria.

[5]   Brenner, D.J., Hall, D., Eric, J. and Phil, D. (2007) Computed Tomography—An Increasing Source of Radiation Exposure. New England Journal of Medicine, 357, 2277-2284.

[6]   Ngaile, J.E. and Peter, K.M. (2006) Estimation of Patient Organ Doses from CT Examinations in Tanzania. Journal of Applied Clinical Medical Physics, 7, 80-94.

[7]   National Council on Radiation Protection and Measurements (2009) Ionizing Radiation Exposure of the Population of the United States: Report No.160. Bethesda.

[8]   Zhang, Y., Li. X., Segars, W.P. and Samei, E. (2012) Organ Doses, Effective Doses, and Risk Indices in Adult CT: Comparison of Four Types of Reference Phantoms across Different Examination Protocols. Medical Physics, 39, 3404-3423.

[9]   United Nations Scientific Committee on the Effects of Atomic Radiation (2010) UNSCEAR 2008 Report to the General Assembly Scientific. Volume 1, Annexes A and B, New York.

[10]   Aird, E.G.A. and Conway, J. (2002) CT Simulation for Radiotherapy Treatment Planning. British Journal of Radiology, 75, 937-949.

[11]   Lam, D., Wootton-Gorges, S.L., McGahan, J.P., Stern, R. and Boone, J.M. (2011) Abdominal Paediatric Cancer Surveillance Using Serial Computed Tomography: Evaluation of Organ Absorbed Dose and Effective Dose. Seminars in Oncology, 38, 128-135.

[12]   ICRP International Commission on Radiological Protection (2007) The 2007 Recommendations of the International Commission on Radiological Protection. Publication No. 103, Ann ICRP, 37.

[13]   Madan, M.R. and Donald, P.F. (2010) Tracking Radiation Exposure of Patients. The Lancet, 376, 754-755.

[14]   Rehani, M.M. and Donald, P.F. (2011) Patient Exposure Tracking: The IAEA Smart Card Project. Radiation Protection Dosimetry, 147, 314-316.

[15]   Murphy, M.J., Balter, J., Balter, S., BenComo, J.A., Das, I.J., Jiang, S.B., et al. (2007) The Management of Imaging Dose during Image-Guided Radiotherapy: Report of the AAPM Task Group 75. Medical Physics, 34, 4041-4063.

[16]   AAPM (1993) Specification and Acceptance Testing of Computed Tomography Scanners. Report of the AAPM Task Group 2, Report No. 39, American Association of Physicists in Medicine, New York.

[17]   Kubo, T., Lin, P.J., Stiller, W., Takahashi, M., Kauczor, H.-U., Ohno, Y. and Hatabu, H. (2008) Radiation Dose Reduction in Chest CT: A Review. American Journal of Roentgenology, 190, 335-343.

[18]   Dougeni, E., Faulkner, K. and Panayiotakis, G. (2012) A Review of Patient Dose and Optimisation Methods in Adult and Paediatric CT Scanning. European Journal of Radiology, 81, 665-683.

[19]   McNitt-Gray, M.F., Cagnon, C., Solberg, T.D. and Chetty, I. (1999) Radiation Dose from Spiral CT: The Relative Effects of Collimation and Pitch. Medical Physics, 26, 409-414.

[20]   Harki, E.M.T. and AL-Kinani, A.T. (2007) Measurement of Organ Dose in Chest CT Examination Using Monte Carlo Simulation. Iranian Journal of Radiation Research, 4, 205-209.

[21]   Groves, A.M., Owen, K.E., Courtney, H.M., Yates, S.J., Goldstone, K.E., Blake, G.M. and Dixon, A.K. (2004) 16-Detector Multislice CT: Dosimetry Estimation by TLD Measurement Compared with Monte Carlo Simulation. The British Journal of Radiology, 77, 62-65.

[22]   Fearon, F., Xie, H., Cheng. J.Y., Ning, H., Zhuge, Y. and Miller, R.W. (2011) Patient-Specific CT Dosimetry Calculation: A Feasibility Study. Journal of Applied Clinical Medical Physics, 12, 196-209.

[23]   Struelens, L., Vanhavere, F. and Smans, K. (2008) Experimental Validation of Monte Carlo Calculations with a Voxelized Rando-Alderson Phantom: A Study on Influence Parameters. Physics in Medicine and Biology, 53, 5831-5844.

[24]   Mukundan, S., Wang, I.P., Frush, D.P., Yoshizumi, T., Marcus, J., Kloeblen, E. and Moore, M. (2007) MOSFET Dosimetry for Radiation Dose Assessment of Bismuth Shielding of the Eye in Children. American Journal of Roentgenology, 188, 1648-1650.

[25]   Verhaegen, F., Lemire, M., Hallil, A. and Hegyi, G. (2008) Surface Dosimetry in a CT Scanner Using MOSFET Detectors and Monte Carlo Simulations. Journal of Physics: Conference Series, 102, 1-7.

[26]   Hurwitz, L.M., Yoshizumi, T., Reiman, R.E., Goodman, P.C., Paulson, E.K., Frush, D.P., Toncheva, G., Nguyen, G. and Barnes, L. (2006) Radiation Dose to the Fetus from Body MDCT during Early Gestation. American Journal of Roentgenology, 186, 871-876.

[27]   Jaffe, T.A., Gaca, A.M., Delaney, S., Yoshizumi, T.T., Toncheva, G., Nguyen, G. and Frush, D.P. (2007) Radiation Doses from Small-Bowel Follow-Through and Abdomino Pelvic MDCT in Crohn’s Disease. American Journal of Roentgenology, 189, 1015-1022.

[28]   Hidajat, N., Maurer, J., Schroder, R.J., Nunneman, A., Wolf, M., Pauli, K., et al. (1999) Relationships between Physical Dose Quantities and Patient Dose in CT. The British Journal of Radiology, 72, 556-561.

[29]   Geleijns, J., Van Unnik, J.G., Zoetelief, J., Zweers, D. and Broerse, J.J. (1994) Comparison of Two Methods for Assessing Patient Dose from Computed Tomography. The British Journal of Radiology, 67, 360-365.

[30]   Shrimpton, P.C., Jones, D.G., Hillier, M.C., Wall, B.F., Le Heron, J.C. and Faulkner, K. (1991) Survey of CT Practice in the UK. Part 2: Dosimetric Aspects. NRPB-R249, HMSO, London.

[31]   Li, X., Samei, E., Segars, W.P., Sturgeon, G.M., Colsher, J.G., Toncheva, G., Yoshizumi, T.T. and Frush, D.P. (2011) Patient-Specific Radiation Dose and Cancer Risk Estimation in CT: Part I. Development and Validation of a Monte Carlo Program. Medical Physics, 38, 397-407.

[32]   McCollough, C.H., Leng, S., Yu, L., Cody, D.D., Boone, J.M. and McNitt-Gray, M.F. (2011) CT Dose Index and Patient Dose: They Are Not the Same Thing. Radiology, 259, 311-316.

[33]   Demarco, J.J., Cagnon, C.H., Cody, D.D., Stevens, D.M., Mccollough, C.H., O’Daniel, J. and Mcnitt-Gray, M.F. (2005) A Monte Carlo Based Method to Estimate Radiation Dose from Multidetector CT (MDCT): Cylindrical and Anthropomorphic Phantoms. Physics in Medicine and Biology, 50, 3989-4004.

[34]   Osei, E.K. and Darco, J. (2013) A Survey of Organ Equivalent and Effective Doses from Diagnostic Radiology Procedures. ISRN Radiology, 2013, Article ID: 204346.

[35]   European Commission (1999) European Guidelines on Quality Criteria for Computed Tomography EUR 16262 EN. Luxemburg Office for Official Publications of the European Communities.

[36]   AAPM (2007) The Measurement, Reporting and Management of Radiation Dose in CT: Report of the AAPM Task Group 23. Report No.96, American Association of Physicists in Medicine, New York.

[37]   Shope, T.B., Gagne, R.M. and Johnson, G.C. (1981) A Method for Describing the Doses Delivered by Transmission X-Ray Computed Tomography. Medical Physics, 8, 488-495.

[38]   McCollough, C. (2008) CT Dose: How to Measure, How to Reduce. Health Physics, 95, 508-517.

[39]   Christner, J.A., Kofler, J.M. and McCollough, J.H. (2010) Estimating Effective Dose for CT Using Dose-Length Product Compared With Using Organ Doses: Consequences of Adopting International Commission on Radiological Protection Publication 103 or Dual-Energy Scanning. American Journal of Roentgenology, 194, 881-889.

[40]   ICRP International Commission on Radiological Protection (1977) Recommendations of the ICRP. ICRP Publication 26, Ann ICRP, Volume 1.

[41]   ICRP International Commission on Radiological Protection (1990) Recommendations of the International Commission on Radiological Protection. ICRP Publication 60, Ann ICRP, Volume 21.

[42]   ImPACT Imaging Performance Assessments of CT. CT Patient Dosimetry Spreadsheet (v1.03, 24/08/2010).

[43]   CT-Expo, Medizinische Hochschule, Hannover, Germany.

[44]   Jones, D.G. and Shrimpton, P.C. (1991) Survey of CT Practice in the UK. Part 3: Normalised Organ Doses Calculated using Monte Carlo Techniques. NRPB-R250, HMSO, London.

[45]   The Alderson Radiation Therapy Phantoms. Radiology Support Devices, Inc.

[46]   MIKROLAB s.c. POLAND.

[47]   Tsapaki, V., Kottou, S. and Papadimitriou, D. (2001) Application of European Commission Reference Dose Levels in CT Examinations in Crete, Greece. The British Journal of Radiology, 74, 836-840.

[48]   Breiki, G., Abbas, Y., El-Ashry, M. and Diyab, H. (2008) Evaluation of Radiation Dose and Image Quality for Patients Undergoing Computed Tomography (CT) Examinations. Proceedings of the IX Radiation Physics & Protection Conference, Nasr City-Cairo, 15-19 November 2008.

[49]   Nishizawa, K., Maruyama, T., Takayama, M., Okada, M., Hachiya, J. and Furuya, Y. (1991) Determinations of Organ Doses and Effective Dose Equivalents from Computed Tomographic Examination. The British Journal of Radiology, 64, 20-28.

[50]   Shrimpton, P.C., Wall, B.F. and Fischer, E.S. (1984) The Tissue Equivalence of the Alderson Rando Anthropomorphic Phantom for X-Rays of Diagnostic Qualities. Physics in Medicine and Biology, 47, 463-467.