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Geoffrey S. Ibbott, Ph.D.

Present Title & Affiliation

Primary Appointment

Professor and Chief, Section of Outreach Physics, Department of Radiation Physics, Division of Radiation Oncology, UT M. D. Anderson Cancer Center, Houston, TX
Director, RPC; Director ADCL, Department of Radiation Physics, Division of Radiation Oncology, UT M. D. Anderson Cancer Center, Houston, TX

Education & Training

Degree-Granting Education

1993 Colorado State University, Ft. Collins, CO, PHD, Radiation Biology
1981 University of Colorado Health Sciences Center, Denver, CO, MS, Medical Physics
1979 University of Colorado, Denver, CO, BA, Physics

Board Certifications

6/1994 American Board of Radiology, Diagnostic and Medical Nuclear Physics
6/1983 American Board of Radiology, Therapeutic Radiological Physics

Experience/Service

Academic Appointments

Professor, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, 2005-present

Other Appointments/Responsibilities

Trustee, American Board of Radiology, Tucson, AZ, 2007-present
Vice-Chair, Commission on Medical Physics, American College of Radiology, Fairfax, VA, 2006-present
Member, Council Steering Committee, American College of Radiology, Reston, VA, 2004-present

Consultantships

Member and Consultant, Food and Drug Administration, Rockville, MD, 2000-2013

Institutional Committee Activities

Member, GSBS Medical Physics Steering Committee, 2004-present

Professional Memberships

American Association of Physicists in Medicine
Ad Hoc Committee on Mission Statement Revision, 1/2009-12/2009
Consultant, Task Group 185 (Clinical Commissioning of Proton Therapy Systems), 12/2008-12/2010
Member, Government and Regulatory Affairs Policy Sub-Committee, 2/2008-12/2010
Member, Task Group 167 (AAPM Recommendations on Dosimetry Requirements for Investigational Sources for Interstitial Brachytherapy), 11/2007-12/2009
Member, Working Group on Dosimetry Calibration Protocol for Beams that are Not Compliant, 8/2007-12/2010
Consultant, Task Group 156 (Reference Dosimetry and Patient-Specific Field Calibration for Passively Scattered Proton Therapy Beams), 8/2007-12/2009
Member, Task Group 155 (Small Fields and Non-equilibrium Condition Photon Beam Dosimetry), 8/2007-12/2009
Member, Task Group No. 152 AAPM Recommendations on Regulations for Electronic Brachytherapy, 2/2007-12/2009
Member - Lab Director, Calibration Laboratory Accreditation Subcommittee, 1/2007-12/2009
Member - RPC Representative, Review and Extension of Beam Quality Conversion Factors for TG-51 Protocol, 12/2006-12/2009
Member, Task Group 138 (AAPM Recommendations on Assessing Uncertainty of the Brachytherapy Clinical Dose Evaluation Process), 8/2006-12/2009
Member, Low Energy Brachytherapy Source Dosimetry Work Group, 1/2005-present
Liaison - RPC, Brachytherapy Subcommittee, 1/2005-12/2010
Member - Chair of Brachytherapy Source Registry Work Group, Brachytherapy Subcommittee, 1/2005-12/2010
Member, Awards and Honors, 1/2005-12/2010
Member, Government and Regulatory Affairs, 1/2005-12/2010
Member, High Energy Brachytherapy Source Dosimetry Work Group, 1/2005-12/2010
Workgroup Chair, Brachytherapy Source Registry Work Group, 1/2005-12/2010
Chairman of the Board, 2000
President, 1999
President-Elect, 1998
President, Ohio River Valley Chapter, 1997
Fellow, 1996
Board of Directors, 1995-1997
President, Connecticut Chapter, 1993-1994
President, Rocky Mountain Chapter, 1983
Board of Directors, 1982-1984
Member, 1972-present
American Board of Radiology
Oral Examiner in Radiological Physics, 2009
Oral Examiner in Radiological Physics, 2008
Member, Board of Trustees, 2007-present
Oral Examiner in Radiological Physics, 2007
Oral Examiner in Radiological Physics, 2005
Oral Examiner in Radiological Physics, 2003
Oral Examiner in Radiological Physics, 2002
Oral Examiner in Radiological Physics, 2000
Oral Examiner in Radiological Physics, 1998
Oral Examiner in Radiological Physics, 1996
Member, Radiation Oncology written examination committee, 1994-present
American College of Radiology
Member, Quality Task Force, QRRO, 2007-2009
Councilor at Large, 2004-present
Fellow, 1998
Councilor at Large, 1996-2001
Member, 1984-present
American Society for Therapeutic Radiology and Oncology
Member, Whole Breast Irradiation Task Force, American Society of Therapeutic Radiology and Oncology, Fairfax, VA, 2009-present
Fellow, 2007
Member, Government Relations Committee, 2001-2009
Member, 1980-present
Council of Scientific Society Presidents
Member, 1998-2000
Health Physics Society
Member, 1971-present
International Electrotechnical Commission
Chair, Subcommittee 62C, 2008-present
Chair, U.S. Technical Advisory Group, 1993-present
Member, Working Group 1, 62C, 1993-present
Member, U.S. Technical Advisory Group, 1990-present
Joint Commission on Accreditation of Healthcare Organizations from Trilateral Committee
Liaison, 1994-1997
Kentucky Medical Society
Member, 1994-2000
North American Hyperthermia Group
Member, 1983-1990
Physicist-Surveyor for Patterns of Care Outcome Surveys
Member, 1985
Physicist-Surveyor for Patterns of Care Outcome Surveys
Member, 1983
Physicist-Surveyor for Patterns of Care Outcome Surveys
Member, 1977-1978
Radiation Research Society
Member, 1983-2001
Radiological Society of Colorado
Member, 1984-1990
Radiological Society of Connecticut
Member, 1991-1994
Texas Radiological Society
Member, 2001-present
Texas Tech University Graduate School, Lubbock, TX
Adjunct Graduate Faculty Member, 2/2009-present

Selected Publications

Peer-Reviewed Original Research Articles
1. Hsu I-C J, Sandler H, Purdy J, Ibbott G, Vigneault E, Ivker R, Pouliot J, Shinohara K. Phase II Trial of Combined High Dose Rate Brachytherapy and External Beam Radiotherapy for Adenocarcinoma of the Prostate: Preliminary Results of RTOG 0321. Int J Radiat Oncol Biol Phys. In Press.
2. Sherry C, Bowkley C, Ibbott G, Kaye A, Kushner DC,. In Through the Out Door: AMCLC 2009 Council Perceptions on Self Referral. Journal of the American College of Radiology 6(12):832-836, 12/2009.
3. Mettler FA, Bhargavan M, Faulkner K, Gilley DB, Fray JE, Ibbott GS, Lipoti JA, Mahesh M, McCrohan JL, Stabin MG, Thomadsen BR, Yoshizumi TT. Radiologic and Nuclear Medicine Studies in the United States and Worldwide: Frequency, Radiation Dose, and Comparison with Other Radiation Sources - 1950-2007. Radiology 253(2):520-31, 11/2009. e-Pub 9/2009. PMID: 19789227.
4. Sakhalkar H, Sterling D, Adamovics J, Ibbott G, Oldham M. Investigation of the feasibility of relative 3D dosimetry in the Radiologic Physics Center head and Neck IMRT phantom using presage/optical-CT. Med Phys 36(7):3371-7, 7/2009. PMID: 19673232.
5. Sakhalkar HS, Adamovics J, Ibbott G, Oldham M. A comprehensive evaluation of the PRESAGE/optical-CT 3D dosimetry system. Med Phys 36(1):71-82, 1/2009. PMCID: PMC2673667.
6. Hartford AC, Palisca MG, Eichler TJ, Beyer DC, Devineni VR, Ibbott GS, Kavanagh B, Kent JS, Rosenthal SA, Schultz CJ, Tripuraneni P, Gaspar LE. American Society for Therapeutic Radiology and Oncology (ASTRO) and American College of Radiology (ACR) Practice Guidelines for Intensity-Modulated Radiation Therapy (IMRT). Int J Radiat Oncol Biol Phys 73(1):9-14, 1/2009. PMID: 19100920.
7. Pourfallah TA, Allahverdi M, Alam NR, Ay MR, Zahmatkesh MH, Ibbott GS. Performance evaluation of MRI-based PAGAT polymer gel dosimeter in an inhomogeneous phantom using EGSnrc code on a Co-60 machine. Appl Radiat Isot 67(1):186-91, 1/2009. e-Pub 9/2008. PMID: 18951810.
8. Tailor R, Ibbott G, Lampe S, Bivens Warren W, Tolani N. Dosimetric characterization of a 131Cs brachytherapy source by thermoluminescence dosimetry in liquid water. Med Phys 35(12):5861-68, 12/2008. PMID: 19175142.
9. Davidson SE, Popple RA, Ibbott GS, Followill DS. Technical note: Heterogeneity dose calculation accuracy in IMRT: Study of five commercial treatment planning systems using an anthropomorphic thorax phantom. Med Phys 35(12):5434-39, 12/2008. PMCID: PMC2736720.
10. Tailor RC, Ibbott GS, Tolani N. Thermoluminescence dosimetry measurements of brachytherapy sources in liquid water. Med Phys 35(9):4063-9, 9/2008. PMID: 18841858.
11. Butler WM, Bice WS, DeWerd LA, Hevezi JM, Huq MS, Ibbott GS, Palta JR, Rivard MJ, Seuntjens JP, Thomadsen BR. Third-party brachytherapy source calibrations and physicist responsibilities: report of the AAPM Low Energy Brachytherapy Source Calibration Working Group. Med Phys 35(9):3860-5, 9/2008. PMID: 18841836.
12. Han Y, Shin EH, Lim C, Kang SK, Park SH, Lah JE, Suh TS, Yoon M, Lee SB, Cho SH, Ibbott GS, Ju SG, Ahn YC. Dosimetry in an IMRT phantom designed for a remote monitoring program. Med Phys 35(6):2519-27, 6/2008. PMID: 18649485.
13. Ibbott G, Ma CM, Rogers DW, Seltzer SM, Williamson JF. Anniversary paper: fifty years of AAPM involvement in radiation dosimetry. Med Phys 35(4):1418-27, 4/2008. PMID: 18491537.
14. Huq MS, Fraass BA, Dunscombe PB, Gibbons JP, Ibbott GS, Medin PM, Mundt A, Mutic S, Palta JR, Thomadsen BR, Williamson JF, Yorke ED. A method for evaluating quality assurance needs in radiation therapy. Int J Radiat Oncol Biol Phys 71(1 Suppl):S170-3, 2008. PMID: 18406920.
15. Ibbott GS, Followill DS, Molineu HA, Lowenstein JR, Alvarez PE, Roll JE. Challenges in Credentialing Institutions and Participants in Advanced Technology Multi-institutional Clinical Trials. Int J Radiat Oncol Biol Phys 71(1):S71-S75, 2008. PMCID: PMC2409281.
16. Frey GD, Ibbott GS, Morin RL, Paliwal BR, Thomas SR, Bosma J. The American Board of Radiology perspective on maintenance of certification: Part IV: Practice quality improvement in radiologic physics. Med Phys 34(11):4158-63, 11/2007. PMID: 18072479.
17. Ibbott GS, Hanson WF, O'Meara E, Kuske RR, Arthur D, Rabinovitch R, White J, Wilensick RM, Harris I, Tailor R. Dose Specification and Quality Assurance of Radiation Therapy Oncology Group Protocol 95-17; A Cooperative Group Study of Iridium-192 Breast Implants as Sole Therapy. Int J Radiat Oncol Biol Phys (*Listed in "Issue Highlights) 69(5):1572-78, 8/2007. PMCID: PMC2180157.
18. Rivard MJ, Butler WM, DeWerd LA, Huq MS, Ibbott GS, Meigooni AS, Melhus CS, Mitch MG, Nath R, Williamson JF. Supplement to the 2004 update of the AAPM Task Group No. 43 Report. Med Phys 34(6):2187-2205, 6/2007. PMID: 17654921.
19. Davidson SE, Ibbott GS, Prado KL, Dong L, Liao Z, Followill DF. Accuracy of two heterogeneity dose calculation algorithms for IMRT in treatment plans designed using an anthropomorphic thorax phantom. Med Phys 34(5):1850-7, 5/2007. PMID: 17555266.
20. Followill D, Radford DA, Cherry C, Molineu A, Fisher G, Hanson WF, Ibbott GS. Design, development, and implementation of the Radiological Physics Center's pelvis and thorax anthropomorphic quality assurance phantoms. Med Phys 34(6):2070-6, 5/2007. PMID: 17654910.
21. Li Z, Das RK, Dewerd LA, Ibbott GS, Meigooni AS, Perez-Calatayud J, Rivard MJ, Sloboda RS, Williamson JF. Dosimetric prerequisites for routine clinical use of photon emitting brachytherapy sources with average energy higher than 50 Kev. Med Phys 34(1):37-40, 1/2007. PMID: 17278487.
22. Ibbott GS, Molineu A, Followill DS. Independent evaluations of IMRT through the use of an anthropomorphic phantom. Technol Cancer Res Treat 5(5):481-7, 10/2006. PMID: 16981790.
23. Timmerman R, Galvin J, Michalski J, Straube W, Ibbott G, Martin E, Abdulrahman R, Swann S, Fowler J, Choy H. Accreditation and quality assurance for Radiation Therapy Oncology Group: Multicenter clinical trials using stereotactic body radiation therapy in lung cancer. Acta Oncologica 45(7):779-86, 9/2006. PMID: 16982540.
24. Randall ME, Ibbott GS. Intensity-modulated radiation therapy for gynecologic cancers: pitfalls, hazards, and cautions to be considered. Semin Radiat Oncol 16(3):138-43, 7/2006. PMID: 16814153.
25. Gillin MT, Dunning BF, Lawton CA, Foley WD, Byhardt RW, Morton G, Baikadi M, Pisansky TT, Michalski JM, Ibbott G, Lopez F. Quality assurance methods for the first Radiation Therapy Oncology Group permanent prostate implant protocol. Brachytherapy 5(3):152-6, Jul-Sep, 7/2006. PMID: 16864066.
26. Tailor RC, Hanson WF, Wells N, Ibbott GS. Consistency of absorbed dose to water measurements using 21 ion-chamber models following the AAPM TG51 and TG21 calibration protocols. Med Phys 33(6):1818-28, 6/2006. PMID: 16872089.
27. Minniti R, Chen-Mayer H, Seltzer SM, Huq MS, Bryson L, Slowey T, Micka JA, DeWerd LA, Wells N, Hanson WF, Ibbott GS. The US radiation dosimetry standards for 60Co therapy level beams, and the transfer to the AAPM accredited dosimetry calibration laboratories. Med Phys 33(4):1074-7, 4/2006. PMID: 16696484.
28. Ibbott G. Methods for image segmentation should be standardized and calibrated. Against the proposition. Med Phys 32(12):3508-10, 12/2005. PMID: 16475749.
29. Chaney E, Ibbott G. Methods for image segmentation should be standardized and calibrated. For the proposition. Med Phys 32(12):3507-8, 12/2005. PMID: 16475748.
30. Molineu A, Followill DS, Balter PA, Hanson WF, Gillin MT, Huq MS, Eisbruch A, Ibbott GS. Design and implementation of an anthropomorphic quality assurance phantom for intensity-modulated radiation therapy for the Radiation Therapy Oncology Group. Int J Radiat Oncol Biol Phys 63(2):577-83, 10/2005. PMID: 16168849.
31. Gifford KA, Horton JL, Jr, Jackson EF, Steger TR, 3rd, Heard MP, Mourtada F, Lawyer AA, Ibbott GS. Comparison of Monte Carlo calculations around a Fletcher Suit Delclos ovoid with radiochromic film and normoxic polymer gel dosimetry. Med Phys 32(7):2288-94, 7/2005. PMID: 16121584.
32. Williamson JF, Butler W, Dewerd LA, Huq MS, Ibbott GS, Mitch MG, Nath R, Rivard MJ, Todor D. Recommendations of the American Association of Physicists in Medicine regarding the impact of implementing the 2004 task group 43 report on dose specification for 103Pd and 125I interstitial brachytherapy. Med Phys 32(5):1424-39, 5/2005. PMID: 15984693.
33. Halvorsen PH, Das IJ, Fraser M, Freedman DJ, Rice RE, 3rd, Ibbott GS, Parsai EI, Robin TT, Jr, Thomadsen BR. AAPM Task Group 103 report on peer review in clinical radiation oncology physics. J Appl Clin Med Phys 6(4):50-64, 2005. e-Pub 11/21/2005. PMID: 16421500.
34. Guerrero T, Zhang G, Segars W, Huang TC, Bilton S, Ibbott G, Dong L, Forster K, Lin KP. Elastic image mapping for 4-D dose estimation in thoracic radiotherapy. Radiat Prot Dosimetry 115(1-4):497-502, 2005. PMID: 16381774.
35. Cho SH, Vassiliev ON, Lee S, Liu HH, Ibbott GS, Mohan R. Reference photon dosimetry data and reference phase space data for the 6 MV photon beam from varian clinac 2100 series linear accelerators. Med Phys 32(1):137-48, 2005. PMID: 15719964.
36. Nag S, Cardenes H, Chang S, Das IJ, Erickson B, Ibbott GS, Lowenstein J, Roll J, Thomadsen B, Varia M. Proposed guidelines for image-based intracavitary brachytherapy for cervical carcinoma: report from Image-Guided Brachytherapy Working Group. Int J Radiat Oncol Biol Phys 60(4):1160-72, 11/2004. PMID: 15519788.
37. Followill DS, Davis DS, Ibbott GS. Comparison of electron beam characteristics from multiple accelerators. Int J Radiat Oncol Biol Phys 59(3):905-10, 7/2004. PMID: 15183494.
38. DeWerd LA, Huq MS, Das IJ, Ibbott GS, Hanson WF, Slowey TW, Williamson JF, Coursey BM. Procedures for establishing and maintaining consistent air-kerma strength standards for low-energy, photon-emitting brachytherapy sources: recommendations of the Calibration Laboratory Accreditation Subcommittee of the American Association of Physicists in Medicine. Med Phys 31(3):675-81, 3/2004. PMID: 15070265.
39. Rivard MJ, Coursey BM, DeWerd LA, Hanson WF, Huq MS, Ibbott GS, Mitch MG, Nath R, Williamson JF. Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations. Med Phys 31(3):633-74, 3/2004. PMID: 15070264.
40. Bencomo JA, Chu C, Tello VM, Cho SH, Ibbott GS. Anthropomorphic breast phantoms for quality assurance and dose verification. J Appl Clin Med Phys 5(1):36-49, 2004. e-Pub 1/2004. PMID: 15753932.
41. Krintz AL, Hanson WF, Ibbott GS, Followill DS. A reanalysis of the Collaborative Ocular Melanoma Study Medium Tumor Trial eye plaque dosimetry. Int J Radiat Oncol Biol Phys 56(3):889-98, 7/2003. PMID: 12788199.
42. Followill DS, Hanson WF, Ibbott GS, Eglezopoulos LR, Chui CS. Differences in electron beam dosimetry using two commercial ionization chambers and the TG-21 protocol: another reason to switch to TG-51. J Appl Clin Med Phys 4(2):124-31, 2003. PMID: 12777147.
43. Followill DS, Stovall MS, Kry SF, Ibbott GS. Neutron source strength measurements for Varian, Siemens, Elekta, and General Electric linear accelerators. J Appl Clin Med Phys 4(3):189-94, 2003. PMID: 12841788.
44. Tailor RC, Followill DS, Hernandez N, Ibbott GS, Hanson WF. Predictability of electron cone ratios with respect to linac make and model. J Appl Clin Med Phys 4(2):172-8, 2003. PMID: 12777153.
45. Cho SH, Ibbott GS. Reference photon dosimetry data: a preliminary study of in-air off-axis factor, percentage depth dose, and output factor of the Siemens Primus linear accelerator. J Appl Clin Med Phys 4(4):300-6, 2003. PMID: 14604419.
46. Tailor RC, Hanson WF, Ibbott GS. TG-51: experience from 150 institutions, common errors, and helpful hints. J Appl Clin Med Phys 4(2):102-11, 2003. PMID: 12777144.
47. Cadman P, Bassalow R, Sidhu NP, Ibbott G, Nelson A. Dosimetric considerations for validation of a sequential IMRT process with a commercial treatment planning system. Phys Med Biol 47(16):3001-10, 8/2002. PMID: 12222862.
48. Tailor RC, Hanson WF. Calculated absorbed-dose ratios, TG51/TG21, for most widely used cylindrical and parallel-plate ion chambers over a range of photon and electron energies. Med Phys 29(7):1464-72, 7/2002. PMID: 12148727.
49. Villarruel S, Ibbott GS, Lai-Fook SJ. Effect of concentration and hydration on restriction of albumin by lung interstitium. Microvasc Res 63(1):27-40, 2002. PMID: 11749070.
50. Gearheart DM, Drogin A, Sowards K, Meigooni AS, Ibbott GS. Dosimetric characteristics of a new 125I brachytherapy source. Med Phys 27(10):2278-85, 10/2000. PMID: 11099194.
51. Popescu CC, Wise J, Sowards K, Meigooni AS, Ibbott GS. Dosimetric characteristics of the Pharma Seed model BT-125-I source. Med Phys 27(9):2174-81, 9/2000. PMID: 11011748.
52. Williamson JF, Coursey BM, DeWerd LA, Hanson WF, Nath R, Rivard MJ, Ibbott G. On the use of apparent activity (Aapp) for treatment planning of 125I and 103Pd interstitial brachytherapy sources: recommendations of the American Association of Physicists in Medicine radiation therapy committee subcommittee on low-energy brachytherapy source dosimetry. Med Phys 26(12):2529-30, 12/1999. PMID: 10619235.
53. Mohiuddin M, Fujita M, Regine WF, Megooni AS, Ibbott GS, Ahmed MM. High-dose spatially-fractionated radiation (GRID): a new paradigm in the management of advanced cancers. Int J Radiat Oncol Biol Phys 45(3):721-7, 10/1999. PMID: 10524428.
54. Parameswaran S, Brown LV, Ibbott GS, Lai-Fook SJ. Hydraulic conductivity, albumin reflection and diffusion coefficients of pig mediastinal pleura. Microvasc Res 58(2):114-27, 9/1999. PMID: 10458927.
55. Parameswaran S, Brown LV, Ibbott GS, Lai-Fook SJ. Effect of concentration and hyaluronidase on albumin diffusion across rabbit mesentery. Microcirculation 6(2):117-26, 6/1999. PMID: 10466114.
56. Williamson JF, Coursey BM, DeWerd LA, Hanson WF, Nath R, Ibbott G. Guidance to users of Nycomed Amersham and North American Scientific, Inc., I-125 interstitial sources: dosimetry and calibration changes: recommendations of the American Association of Physicists in Medicine Radiation Therapy Committee Ad Hoc Subcommittee on Low-Energy Seed Dosimetry. Med Phys 26(4):570-3, 4/1999. PMID: 10227361.
57. Qiu XL, Brown LV, Parameswaran S, Marek VW, Ibbott GS, Lai-Fook SJ. Effect of hyaluronidase on albumin diffusion in lung interstitium. Lung 177(5):273-88, 1999. PMID: 10467020.
58. Qiu XL, Brown LV, Parameswaran S, Ibbott GS, Lai-Fook SJ. Effect of concentration on albumin diffusion in lung interstitium. J Appl Physiol 85(2):575-83, 8/1998. PMID: 9688735.
59. Ibbott GS, Zhang Y, Mohiuddin M, Adams E. Reproduction of radiologic images on plain paper. Radiographics 18(3):755-60, 5/1998. PMID: 9599396.
60. Alam R, Ibbott GS, Pourang R, Nath R. Application of AAPM Radiation Therapy Committee Task Group 23 test package for comparison of two treatment planning systems for photon external beam radiotherapy. Med Phys 24(12):2043-54, 12/1997. PMID: 9434989.
61. Meigooni AS, Kleiman MT, Johnson JL, Mazloomdoost D, Ibbott GS. Dosimetric characteristics of a new high-intensity 192Ir source for remote afterloading. Med Phys 24(12):2008-13, 12/1997. PMID: 9434984.
62. Ibbott GS, Attix FH, Slowey TW, Fontenla DP, Rozenfeld M. Uncertainty of calibrations at the accredited dosimetry calibration laboratories. Med Phys 24(8):1249-54, 8/1997. PMID: 9284248.
63. Ibbott GS, Maryanski MJ, Eastman P, Holcomb SD, Zhang Y, Avison RG, Sanders M, Gore JC. Three-dimensional visualization and measurement of conformal dose distributions using magnetic resonance imaging of BANG polymer gel dosimeters. Int J Radiat Oncol Biol Phys 38(5):1097-103, 7/1997. PMID: 9276377.
64. Meigooni AS, Sanders MF, Ibbott GS, Szeglin SR. Dosimetric characteristics of an improved radiochromic film. Med Phys 23(11):1883-8, 11/1996. PMID: 8947902.
65. Maryanski MJ, Ibbott GS, Eastman P, Schulz RJ, Gore JC. Radiation therapy dosimetry using magnetic resonance imaging of polymer gels. Med Phys 23(5):699-705, 5/1996. PMID: 8724743.
66. Maryanski MJ, Schulz RJ, Ibbott GS, Gatenby JC, Xie J, Horton D, Gore JC. Magnetic resonance imaging of radiation dose distributions using a polymer-gel dosimeter. Phys Med Biol 39(9):1437-55, 9/1994. PMID: 15552115.
67. Schulz RJ, Maryanski MJ, Ibbott GS, Bond JE. Assessment of the accuracy of stereotactic radiosurgery using Fricke-infused gels and MRI. Med Phys 20(6):1731-4, 11/1993. PMID: 8309446.
68. Hazuka MB, Stroud DN, Adams J, Ibbott GS, Kinzie JJ. Prostatic thermoluminescent dosimeter analysis in a patient treated with 18 MV X rays through a prosthetic hip. Int J Radiat Oncol Biol Phys 25(2):339-43, 1/1993. PMID: 8420884.
69. Kantorowitz DA, Miller GJ, Ferrara JA, Ibbott GS, Fisher R, Ahrens CR. Preoperative versus postoperative irradiation in the prophylaxis of heterotopic bone formation in rats. Int J Radiat Oncol Biol Phys 19(6):1431-8, 12/1990. PMID: 1702089.
70. Hazuka MB, Ibbott GS, Kinzie JJ. Hip prostheses during pelvic irradiation: effects and corrections. Int J Radiat Oncol Biol Phys 14(6):1311-7, 6/1988. PMID: 3133330.
71. Watts DL, Ibbott GS. Measurement of beam current and evaluation of scatter production in an 18-MeV accelerator. Med Phys 14(4):662-4, 7/1987. PMID: 3627007.
72. Ibbott GS. Determining costs in radiation therapy. Radiol Manage 9(4):30-4, 1987. PMID: 10284736.
73. Seamon JM Ibbott GS. Errors Introduced in Electron Beam Film Dosimetry. Medical Dosimetry 12:35-7, 1987.
74. Shabason L, Hendee WR, Ibbott GS. A comparison of photon dosages behind high and low Z shielding blocks in electron fields. Int J Radiat Oncol Biol Phys 7(1):125-8, 1981. PMID: 6790484.
75. Ibbott GS Hendee WR. Master’s Level Graduate Training in Medical Physics at the University of Colorado Health Sciences Center. Am. J. Phys. 48:461-4, 1980.
76. Hills JF, Jr, Ibbott GS, Hendee WR. Computerized patient contours using the scanning arm of compound B-scanner. Med Phys 6(4):309-11, 7/1979. PMID: 481358.
77. Paquette FR, Ahuja AS, Carson PL, Mack LA, Ibbott GS, Johnson ML. A comparative study of computerized tomography and ultrasound imaging for treatment planning of prostatic carcinoma. Int J Radiat Oncol Biol Phys 5(2):289-94, 2/1979. PMID: 457474.
78. Hallberg JR, Ibbott GS, Carson PL, Hendee WR. Computational analysis and dosimetric evaluation of a commercial irregular-fields computer program. Med Phys 4(6):528-34, 11/1977. PMID: 412050.
79. Ibbott GS, Boothe KA, Thyfault PJ, Zunde A, Hendee WR. Quality Assurance Workshops for Radiation Therapy Technologists. Appl. Radiology 6:99-100, 1977.
80. Hendee WR Ibbott GS. The Problem of Inhomogeneities in Radiation Therapy. Appl. Radiology 5:138, 1976.
81. Ibbott GS, Barnes JE, Hall GR, Hendee WR. Stem corrections for ionization chambers. Med Phys 2(6):328-30, 11/1975. PMID: 1196264.
82. Thieme GA, Hendee WR, Ibbott GS, Carson PL, Kirch DL. Cross-sectional anatomic images by gamma ray transmission scanning. Acta Radiol Ther Phys Biol 14(1):81-111, 2/1975. PMID: 1101651.
83. Chaney EL, Hendee WR, Ibbott GS, Frank MN. Physics Instruction for Radiologic Technologists. Amer. J. of Phys. 42:465-73, 1974.
84. Hendee WR, Ibbott, GS, Crusha KL. H-Toluene. H-Hexadecane as Internal Standards for Toluene-and Dioxane-Based Liquid Scintillation Cocktails. Int. J. Appl. Radiation and Isotopes 23:90, 1972.
85. Ibbott GS, Hendee WR, Crusha KL, Hall GR. Record-keeping in a radiation safety office by timesharing digital computer. Health Phys 21(4):581-4, 10/1971. PMID: 5115131.
86. Ibbott GS Hendee WR. Beam-shaping platforms and the skin-sparing advantage of Co60 radiation. Am J Roentgenol Radium Ther Nucl Med 108(1):193-6, 1970. PMID: 5410702.
87. Gower RG, Hendee WR, Ibbott GS. Ultraviolet-induced changes in residual thermoluminescence from gamma-irradiated lithium fluoride. Health Phys 17(4):607-11, 10/1969. PMID: 5344471.
88. Hendee WR, Ibbott GS, Gilbert DB. Effects of total dose on energy dependence of TLD-100 LiF dosimeters. Int J Appl Radiat Isot 19(5):431-7, 5/1968. PMID: 5655872.
89. Hendee WR, Golden R, Garciga CE, Gilbert DB, Ibbott GS. Depth dose measurements with lithium fluoride. Am J Roentgenol Radium Ther Nucl Med 102(3):694-6, 3/1968. PMID: 5639585.
90. Hendee WR, Golden R, Garciga CE, Gilbert DB, Ibbott GS. Lithium Fluoride Depth Dose Measurements. Radiology 90:371, 1968.

Invited Articles
1. Morin RL, Ibbott GS. Gel dosimetry. J Am Coll Radiol 3(2):144-6, 2/2006. PMID: 17412026.
2. Chaney E, Ibbott G, Hendee WR. Methods for image segmentation should be standardized and calibrated. Med Phys 32(12):3507-10, 12/2005.
3. Ibbott GS, Hevezi JM. Reimbursement for high dose rate brachytherapy should be based on the number of dwell positions of the source during treatment. Med. Phys. 26:347-9, 3/1999.
4. Thrall DE, Ibbott GS. Physics and treatment planning. Semin Vet Med Surg (Small Anim) 10:135-47, 8/1995. PMID: 8532969.
Other Articles
1. Sakhalkar HS, Adamovics J, Ibbott G, Oldham M. An Investigation into the Robustness of Optical-CT Dosimetry of a Radiochromic Dosimeter Compatible with the RPC Head-and-Neck Phantom. Journal of Physics: Conference Series 164:012059, 2009.
2. Heard M, Ibbott G, Followill D, White RA, Jackson E, Salehpour S. Characterization of a normoxic polyacrylamide gel using MRI and optical CT. Journal of Physics: Conference Series 164:012005, 2009.
3. Sakhalkar HS, Sterling D, Adamovics J, Ibbott G, Oldham M. Investigating the Feasibility of 3D Dosimetry in the RPC IMRT H&N Phantom. Journal of Physics: Conference Series 164:012058, 2009.
4. Davidson S, Cui J, Followill D, Ibbott S. A Flexible Monte Carlo Tool for Patient or Phantom Specific Calculations: Comparison with Preliminary Validation Measurements. Journal of Physics: Conference Series 102:012004, 2008.
5. Ibbott GS. Clinical applications of gel dosimeters. Journal of Physics: Conference Series 56:108-31, 2006.
6. Ibbott G. Applications of Gel Dosimetry. Journal of Physics: Conference Series 3:58-77, 2004.
7. Heard MP, Ibbott GS. Measurement of brachytherapy sources using MAGIC gel. Journal of Physics: Conference Series 3:221-3, 2004.
8. Gifford K, Horton J, Steger T, Heard M, Jackson E, Ibbott G. Verification of Monte Carlo calculations around a Fletcher Suit Delclos ovoid with normoxic polymer gel dosimetry. Journal of Physics: Conference Series 3:217-20, 2004.
9. Ibbott G, Beach M, Maryanski M. An anthropomorphic head phantom with a BANG® polymer gel insert for dosimetric evaluation of IMRT treatment delivery. Standards and Codes of Practice in Medical Radiation Dosimetry 2:361-8, 2002.
10. Aguirre J, Tailor R, Ibbott G, Stovall M, Hanson W. Thermoluminescence Dosimetry as a Tool for the Remote Verification of Output for Radiotherapy Beams: 25 Years of Experience. Standards and Codes of Practice in Medical Radiation Dosimetry 2:191-9, 2002.
11. Izewska J, Svensson H, Ibbott G. Worldwide Quality Assurance Networks for Radiotherapy Dosimetry. Standards and Codes of Practice in Medical Radiation Dosimetry 2:139-55, 2002.
12. Ibbott G, Maryanski M, Drogin A, Gearheart D, Painter T, Meigooni A. Characterization of a New Brachytherapy Source by BANG® Gel Dosimetry. DosGel 99: Proceedings of the 1st International Workshop on Radiation Therapy Gel Dosimetry. Canadian Organisation of Medical Physicists and the Canadian College of Physicists in Medicine:196-8, 1999.

Abstracts
1. Leif J, Roll J, Davis C, Ibbott G. Rapid Reviews Reduce the Rate of Protocol Deviations. Int J Radiat Oncol Biol Phys 75(3):S617, 11/2009.
2. Ibbott G, Alvarez P, Aguirre JF, Followill D. Implementation of an Optically Stimulated Luminescence (OSL) System for Remote Dosimetry Audits. Radiotherapy and Oncology 92(1):S51, 8/2009.
3. Followill D, Lowenstein J, Ibbott G. The Radiological Physics Center Annual TLD Audit's Role in Clinical Trial Quality Assurance. Radiotherapy and Oncology 92(1):S134, 8/2009.
4. Lowenstein J, Roll J, Ibbott GS. Cervix Brachytherapy Dosimetry: Observed Improvement in Data Submitted to Clinical Trials. Med Phys 36(6):2524, 6/2009.
5. Caruthers D, Ibbott GS, Followill D. Commissioning a New Anthropomorphic Spine and Lung Phantom to be Used for Remote Dose Verfication of Spine Radiosurgery. Med Phys 36(6):2651, 6/2009.
6. Georgiev G, Followill D, Ibbott G, Kry S, Fontenot J, White A, Mahajan A. Comparison of Out-of-Field Doses in Pediatric Patients From Craniospinal Irradiations Using Photon, Electron and Proton Spinal Fields. Med Phys 36(6):2583, 6/2009.
7. Ibbott GS. Credentialing for Clinical Trials: The Role of the RPC. Med Phys 36(6):2687, 6/2009.
8. Heard M, Ibbott G, Followill D, Jackson E, Salehpour M, White A. Evaluation of a PAGAT Gel for Use in An Anthropomorphic Phantom. Med Phys 36(6):2581, 6/2009.
9. Grant R, Ibbott G, Sahoo N, Tucker S, Zhu X, Followill D. Evaluation of an Anthropomorphic Pelvis Phantom for Proton Therapy. Med Phys 36(6):2607, 6/2009.
10. Aguirre J, Alvarez P, Followill D, Ibbott G, Amador C, Tailor R. Optically Stimulated Light Dosimetry: Commissioning of An Optically Stimulated Luminescence (OSL) System for Remote Dosimetry Audits, The Radiological Physics Center Experience. Med Phys 36(6):2591, 6/2009.
11. Ibbott GS, Frey G, Morin R, Thomas S. Requirements and Opportunities for Maintenance of Certification. Med Phys 36(6):2757, 6/2009.
12. Yu Z, Tailor R, Ibbott G, Wells N, Prado K. Response of OneDoseTM and TLD 100 Dosimeters Over 6 MV to PD-103 Equilvalent Energies. Med Phys 36(6):2591, 6/2009.
13. Followill D, Lowenstein J, Palmer L, Ibbott G. The Radiological Physics Center's Annual TLD Machine Calibration Audit and Its Impact on Clinical Trials. Med Phys 36(6):2595, 6/2009.
14. Davidson S, Cui J, Kry S, Vicic M, Deasy J, White R, Ibbott G, Followill D. Validation and Benchmark of a Source Model for a Varian 6 MV Photon Beam Using Monte Carlo Calculations. Med Phys 36(6):2625, 6/2009.
15. Hsu I, Bae K, Shinohara K, Pouliot J, Purdy J, Ibbott G, Speight J, Vigneault E, Ivker R, Sandler H. Phase II Trial of Combined High Dose Rate Brachytherapy and External Beam Radiotherapy for Adenocarcinoma of the Prostate: Preliminary Results of RTOG 0321. Int J Radiat Oncol Biol Phys 72(1):S133, 9/2008.
16. Oldham M, Sakhalkar H, Adamovics J, Molineu A, Ibbott G. The Feasibility of Comprehensive IMRT Verification using Novel 3D Dosimetry Techniques Compatible with the RPC Head and Neck Phantom. Int J Radiat Oncol Biol Phys 72(1):S145, 9/2008.
17. Alvarez P, Molineu A, Hernandez N, Hall F, Followill D, Ibbott G. A Comparison of Heterogeneity Correction Algorithms. Med Phys 35(6):2888, 6/2008.
18. Oldham M, Sterling D, Sakhalkar H, Molineu A, Adamovics J, Ibbott G. Evaluation of PRESAGE/optical-CT 3D Dosimetry for Commissioning a Linac for IMRT. Med Phys 35(6):2757, 6/2008.
19. Heard M, Ibbott G. Evaluation of the Performance of the Fast Scanning Platform of An OCT System. Med Phys 35(6):2923, 6/2008.
20. Molineu A, Lowenstein J, Hernandez N, Alvarez P, Followill D, Ibbott G. Has IMRT Delivery Improved in the Last 5 years?. Med Phys 35(6):2762, 6/2008.
21. Heard M, Followill D, White R, Jackson E, Salehpour M, Ibbott G. Identification of a 3D Dosimeter Best-Suited for Use by the RPC. Med Phys 35(6):2889, 6/2008.
22. Frey G, Thomas S, Morin R, Ibbott G, Yester M. MOC: The ABR Perspective. Med Phys 35(6):2943, 6/2008.
23. Homnick J, Ibbott G, Springer A, Aguirre J. Optically Stimulated Luminescene (OSL) Dosimeters Can Be Used for Remote Dosimetry Services. Med Phys 35(6):2994, 6/2008.
24. Followill D, Molineu A, Lowenstein J, Alvarez P, Aguirre J, Ibbott G. Quality Audits of the Calibration for TG-51 Non-Complaint Beams by the Radiological Physics Center. Med Phys 35(6):2774, 6/2008.
25. Ibbott G. Requirements for Addressing Respiratory Motion in Cooperative Group Clinical Trials (SAM Session). Med Phys 35(6):2961, 6/2008.
26. Bellon M, Followill D, Ibbott G, White R, Salehpour M, Mahajan A, Kry S, Ding C. Risk of Secondary Fatal Malignancies From Cyberknife Radiosurgery. Med Phys 35(6):2983, 6/2008.
27. Ibbott G. The RPC's Evaluation of Advanced Technology Radiation Therapy. Med Phys 35(6):2883, 6/2008.
28. Davidson S, Cui J, Deasy J, Ibbott G, Followill D. Verification of a Monte Carlo-Based Source Model for a Varian 10 MV Photon Beam. Med Phys 35(6):2804, 6/2008.
29. Homnick J, Ibbott G, Springer A, Aguirre F. OSL Dosimeters can be used for Remote Dosimetry. Int J of Radiat Oncol Biol Phys 72(1):S672-3, 2008.
30. Alvarez P, Molineu A, Hernandez N, Followill D, Ibbott G. A Comparison of Heterogeneity Correction Algorithms within a Lung PTV. Med Phys 34:2521, 6/2007.
31. Davidson S, Popple R, Ibbott G, Followill D. A Comprehensive Study on the Heterogeneity Dose Calculation Accuracy in IMRT using an Anthropomorphic Thorax Phantom. Med Phys 34:2520, 6/2007.
32. Martin R, Bencomo J, Martin M, Bankson J, Heard M, Kaluarachchi K, Webb D, Wells N, Ibbott G. A Method for Extracting the Relevant MRI Information from Normoxic Polymer Gels Exposed to Low Doses. Med Phys 34:2405, 6/2007.
33. Nitsch P, Ibbott G, Dieterich S, Followill D. Assessment of CyberKnife's Heterogeneity Dose Calculation Algorithm and Respiratory Tracking System using an Anthropomorphic Thorax Phantom. Med Phys 34:2641-42, 6/2007.
34. Davidson S, Cui J, Followill D, Ibbott G, Deasy J. Benchmarking a Flexible Monte Carlo (MC) Tool Based on the Dose Planning Method (DPM) for use in evaluating IMRT Treatment Planning Systems. Med Phys 34:2574-75, 6/2007.
35. Tailor R, Ibbott G, Tolani N. Design of a Jig for Thermoluminescence Dosimetry of Brachytherapy Sources in Liquid Water and the Determination of a Correction Factor for Water-Equivalent Plastics. Med Phys 34:2432, 6/2007.
36. Ibbott G. Developing Medical Physics Technical Standards through the AAPM and ANSI. Med Phys 34:2519-20, 6/2007.
37. Heard M, Adamovics J, Ibbott G. Development of a Modified 3D Radiochromic Dosimeter for Clinical Proton Beams. Med Phys 34:2435, 6/2007.
38. Tailor R, Ibbott G, Lampe S, Bivens W, Tolani N. Dosimetric Characterization of Model CS-1 1131Cs Source by Thermoluminescence Dosimetry in Liquid Water. Med Phys 34:2239, 6/2007.
39. Han Y, Shin EH, Yoon MK, Lee SB, Ju SG, Lim CL, Park SH, Kang SK, Lah JE, Cho SH, Ibbott G, Ahn YC. Dosimetry in an IMRT Phantom Designed for a Remote Auditing Program. Med Phys 34:2444, 6/2007.
40. Bivens W, Ibbott G, Maryanski M, Heard M, Followill D, Zhu X. Linear Energy Transfer (LET) Dependence of BANG® Polymer Gel Dosimeters in Proton Beams. Med Phys 34:2467, 6/2007.
41. Ibbott G. Requirements for Addressing Respiratory Motion in Cooperative Group Clinical Trials. Med Phys 34:2615-16, 6/2007.
42. Ibbott G. RPC Programs. Med Phys 34:2584, 6/2007.
43. Rivard JM, Butler WM, DeWerd LA, Huq MS, Ibbott GS, Melhus CS, Mitch MG, Nath R, Williamson JF. AAPM TG-43 update for 2004 and beyond. Med Phys 33:2157, 2006.
44. Molineu A, Alvarez P, Hernandez N, Followill DS, Ibbott GS. Adequacy of IMRT QA Procedures as determined by Irradiations of a Head and Neck IMRT Anthropomorphic Phantom. Int J of Radiat Oncol Biol Phys 66:S128, 2006.
45. Alvarez PE, Molineu A, Hernandez N, Followill D, Ibbott G. Analysis of Multiple Irradiations of an Anthropomorphic Thorax Phantom Containing Lung Heterogeneities. Int J of Radiat Oncol Biol Phys 66:S685, 2006.
46. Alvarez P, Hernandez N, Followill D, Tailor R, Ibbott G. Characterization of EBT versus MD55 gafchromic® films for relative dosimetry measurements. Med Phys 33:2217-18, 2006.
47. Hecox R, Gibbons J, Followill D, Ibbott G. Dose calculation accuracy in the presence of high-z materials using megavoltage CT for treatment planning. Med Phys 33:2087-8, 2006.
48. Alvarez P, Molineu A, Hernandez N, Followill D, Ibbott G. Evaluation of heterogeneity corrections algorithms through the irradiation of a lung phantom. Med Phys 33:2214, 2006.
49. Davidson S, Prado K, Ibbott G, Followill D. Hetergeneity dose calculation accuracy in IMRT using an anthropomorphic thorax phantom. Med Phys 33:2106, 2006.
50. Tailor RC, Tolani NB, Ibbott GS, Ha CS. Lessons From the In-Vivo TLD Dosimetry Practice for Patients Treated With Total Skin Electron Radiation Therapy (TSEB) at M.D. Anderson Cancer Center. Int J of Radiat Oncol Biol Phys 66:S716-7, 2006.
51. Simon W, Kozelka J, Rose M, Liu C, Palta J, Dempsey J, Lynch B, Bayouth J, Pavord D, Ibbott G, Followill D. LINAC dosimetry: benchmark data set uncertainty. Med Phys 33:2118, 2006.
52. Lowenstein J, Davis C, Roll J, Harris I, Hall F, Followill D, Ibbott G. The credentialing process for the NSABP B-39/RTOG 0413 partial breast irradiation trial. Med Phys 33:2140, 2006.
53. Followill D, Molineu A, Alvarez P, Ibbott G. The state of radiotherapy physics through the eyes of a quality auditor. Med Phys 33:2283, 2006.
54. Leif J, Roll J, Followill D, Ibbott G. The Value of Credentialing. Int J of Radiat Oncol Biol Phys 66:S716, 2006.
55. Molineu A, Alvarez P, Hernandez N, Followill DS, Ibbott GS. Analysis of errors made during 138 IMRT irradiations of an anthropomorphic phantom. Int J of Radiat Oncol Biol Phys 63:S58, 2005.
56. Followill D, Molineu A, McGary J, Ibbott G. Clinical reference dosimetry of a hi-art II helical tomotherapy machine. Med Phys 32:2089, 2005.
57. Lowenstein J, Roll J, Davis C, Holguin P, Duong H, Followill D, Ibbott G. Credentialing requirements for NSABP B-39 / RTOG 0413. Med Phys 32:2020-1, 2005.
58. Shoales J, Followill D, Ibbott G, Balter P, Tolani N. Development of an independent audit device for remote verification of 4D radiotherapy. Med Phys 32:2128, 2005.
59. Alvarez P, Molineu A, Hernandez N, Followill D, Ibbott G. Evaluation of doses delivered by SBRT to the lung of an anthropomorphic thorax phantom. Med Phys 32:2043, 2005.
60. Followill D, Molineu A, McGary J, Hernandez N, Ibbott G. Evaluation of the tomotherapy planning station heterogeneity correction algorithm using an anthropomorphic phantom. Med Phys 32:2167, 2005.
61. Molineu A, Hernandez N, Alvarez P, Followill D, Ibbott G. IMRT head and neck phantom irradiations: correlation of results with institution size. Med Phys 32:1983-4, 2005.
62. Schild SE, McGinnis WL, Graham D, Hillman S, Ibbott G, Northfelt D, Garces Y, Yee G, Bollinger J, Jett J. Results of a phase I trial of concurrent chemotherapy and escalating doses of radiation for unresectable non-small cell lung cancer. Int J of Radiat Oncol Biol Phys 63:S44, 2005.
63. Davidson S, Followill D, Ibbott G, Prado K. The evaluation of several commercial IMRT treatment planning system heterogeneity dose calculation algorithms using an anthropomorphic thorax phantom. Med Phys 32:1988, 2005.
64. Followill D, Lowenstein J, Jhingran A, Roll J, Hernandez N, Ibbott G. The Radiological Physics Center’s anthropomorphic quality assurance phantom family: new developments. Med Phys 32:2129, 2005.
65. Ibbott G. The Radiological Physics Center's QA activities. Med Phys 32:2153, 2005.
66. Zhang GG, Guerro TM, Forster K, Fischer G, Fitzpatrick M, Starkschall G, Ibbott G. Validation of the Path Integration of 4D Dose Distributions with 4D Phantom Measurements. Int J Radiat Oncol Biol Phys 60(1):S608-9, 9/2004.
67. Rivard MJ, Goetsch SJ, Drzymala RE, Bourland JD, DeWerd LA, Gibbons JP, Ibbott GS, Kunugi KA, Moskvin V, Walker LD. A working group for improving consistency of quality assurance, treatment planning, and clinical implementation for gamma knife® stereotactic radiosurgery. 2004 Proceedings of the 12th International Meeting of the Leksell Gamma Knife® Society 91, 2004.
68. Alvarez P, Molineu A, Hernandez N, Followill D, Balter P, Hanson W, Ibbott G. Anthropomorphic Phantoms for Quality Assurance in Radiation Therapy. Med. Phys. 31:1732, 2004.
69. BenComo J, Stewart B, Wells N, Ibbott G. Could MOSFET Detectors Substitute TLD Dosimeter as a Remote Monitoring Device of Megavoltage Beams Output? . Med. Phys. 31:1875, 2004.
70. Halvorsen P, Das I, Freedman D, Ibbott G, Parsai E, RiceR, RobinT, Thomadsen B. Effective Peer Review for Clinical Radiation Oncology Physicists: Task Group 103's Preliminary Findings. Med. Phys. 31:1743, 2004.
71. Esteban J, Tailor R, Cho S, Ibbott G. Energy Dependence of a New TLD System for the Characterization of Low Energy Brachytherapy Sources. Med. Phys. 31:1884-5, 2004.
72. Molineu A, Alvarez P, Hernandez N, Followill D, Ibbott G. Evaluation of 60 IMRT Irradiations of An Anthropomorphic H&N Phantom. Med. Phys. 31:1822-3, 2004.
73. Molineu A, Alvarez P, Hernandez N, Followill DS, Ibbott GS. Evaluation of IMRT for Institutions Participating in NCI Sponsored Clinical Trials. International Journal of Radiation Oncology Biology Physics 60:S319, 2004.
74. Heard M, Ibbott G. Gel Dosimetry Technique for Measurements in High Dose Gradients. Med. Phys. 31:1888, 2004.
75. Followill D, Lowenstein J, Ibbott G. High-Energy Photon Standard Dosimetry Data: A Quality Assurance Tool. Med. Phys. 31:1782, 2004.
76. Cho S, Vassiliev O, Liu H, Ibbott G, Mohan R. On the Choice of Measured Depth Dose Data for the Monte Carlo Modeling of the 18 MV Photon Beam: Shifted Vs. Unshifted. Med. Phys. 31:1906, 2004.
77. Urie M, Ulin K, Followill D, Ibbott G, Olch A, Palta J, Purdy J. Results and Analysis by QARC of the IMRT Benchmark Required by the NCI for Participation in Clinical Trials. Med. Phys. 31:1915-6, 2004.
78. Fisher G, Followill D, Ibbott G. The Accuracy of 3-D Inhomogeneity Photon Algorithms in Commercial Treatment Planning Systems Using a Heterogeneous Lung Phantom. Med. Phys. 31:1714, 2004.
79. Purdy J, Palta J, Ibbott G. The Advanced Technology QA Consortium (ATC). Med. Phys. 31:1833, 2004.
80. BenComo J, Cho S, Sun T, Lee S, Ibbott G. Use of MOSFET Detectors to Verify Dose Calculations in An Anthropomorphic Breast Phantom. Med. Phys. 31:1926, 2004.
81. Gifford K, Horton J, Jackson E, Steger T, Heard M, Mourtada F, Lawyer A, Ibbott G. Verification of Monte Carlo Calculations Around a Fletcher Suit Delclos Ovoid with Radiochromic Film and Normoxic Polymer Gel Dosimetry. Med. Phys. 31:1808, 2004.
82. Rivard MJ, Coursey BM, DeWerd LA, Hanson WF, Huq MS, Ibbott GS, Mitch MG, Nath R, Williamson JF. Update of the AAPM Task Groug No. 43 Report - A Revised AAPM Protocol for Brachytherapy Dose Calculations. Int J Radiat Oncol Biol Phys 57(2):S430, 10/2003.
83. Borges JA, BenComo J, Ibbott GS. A 3-Dimensional Gel Dosimetry Lung Equivalent (WIP). Med. Phys. 30:1478, 2003.
84. Tailor R, Hanson W, Wells N, Ibbott G. Are Photon and Electron Beam Calibrations More Consistent with TG-51 Than with TG-21?. Med. Phys. 30:1350, 2003.
85. Rogers D, DeWerd L, Ibbott G, Huq M. Changes in Co-60 Air-Kerma Standards: The Rationale for Change and the Impact On Clinical Practice. Med. Phys. 30:1442-3, 2003.
86. Heard M, Ibbott G, Followill D. Characterizing Dose Distributions of Brachytherapy Sources Using Normoxic Gel (WIP). Med. Phys. 30:1333, 2003.
87. Cho S, Kim CH, Ibbott GS. Differences in the Results of MCNP Simulation for Low Energy Photon Sources May be Due to the Choice of Photon Cross Section Libraries. Med. Phys. 30:1464, 2003.
88. Bayouth J, Followill D, Nelson A, Ibbott G, Morrill S. Dosimetric Effect of a Hip Prosthesis When Delivering Intensity Modulated Radiation Therapy (IMRT): A Phantom Study. Radiotherapy and Oncology 68:S105, 2003.
89. Esteban J, Ibbott G, Hanson W, Horton J, White A, Cho S. Energy Dependence of a TLD System for Characterizing Low Energy Brachytherapy Sources (WIP). Med. Phys. 30:1349, 2003.
90. Bencomo J, Ibbott G, Lee S, Lii M, Borges J. Evaluation of Two Linear Ionization-Chamber-Arrays as Data Acquisition Systems for Quality Assurance of Photon and Electron Beams. Med. Phys. 30:1350, 2003.
91. Nag S, Cardenes HR, Chang SD, Das IJ, Erickson BA, Ibbott GS, Lowenstein J, Roll J, Thomadsen B, Varia M. Image-based brachytherapy for cervical carcinoma: recommendations of the image-guided brachytherapy working group. Proc Radiol Soc N Am 144, 2003.
92. Beach M, Ibbott G, Followill D, Hanson W, Bloch C, Jackson E, Tucker S. Implementation of a Polymer Gel Dosimetry Insert for An Anthropomorphic Phantom Used to Evaluate Head and Neck Intensity-Modulated Radiation Therapy. Med. Phys. 30:1396, 2003.
93. Ibbott GS, Beach ML, Maryanski MJ. IMRT QA with an Anthropomorphic Phantom Employing a Polymer Gel Dosimeter. International Organization for Medical Physics Proceedings 1, 2003.
94. Tailor R, Followill DS, Hernandez N, Zhu TS, Ibbott GS. Quality-Assurance Check of Collimator and Phantom-Scatter Factors. Med. Phys. 30:1483, 2003.
95. Fisher G, Followill D, Tolani N, Ibbott G. The Accuracy of 3-D Inhomogeneity Photon Algorithms in Commercial Treatment Planning Systems Using a Heterogeneous Lung Phantom (WIP). Med. Phys. 30:1507, 2003.
96. Tailor R, Esteban J, Ibbott GS. TLD Measurements in Liquid Water of Dosimetry Characteristics of a New 125I Seed. Med. Phys. 30:1470, 2003.
97. Lowenstein JR, Roll J, Ibbott GS. To Plan or Not to Plan: Multiple High Dose Rate (HDR) Brachytherapy Insertions. Med. Phys. 30:1464, 2003.
98. Rivard MJ, Coursey BM, DeWerd LA, Hanson WF, Huq MS, Ibbott GS, Nath R, Williamson JF. Update of AAPM Task Group No. 43 Report - A Revised Protocol for Brachytherapy Dose Calculations. Med. Phys. 30:1431, 2003.
99. Krintz A, Hanson WF, Ibbott GS, Followill DS. A Reanalysis of the Collaborative Ocular Melanoma Study Medium Tumor Trial Eye Plaque Dosimetry. International Journal of Radiation Oncology Biology Physics 54:82A, 2002.
100. Ibbott G, Nelson A, Followill D, Balter P, Hanson W. An anthropomorphic head and neck phantom for evaluation of intensity modulated radiation therapy. Standards and Codes of Practice in Medical Radiation Dosimetry 2:209-17, 2002.
101. Duzenli C, Baldock C, Ibbott G, Schreiner LJ, Jordan K, Oldham M, Short K. CCPM/COMP Symposium on Gel Dosimetry. Med. Phys. 29:1313, 2002.
102. Nelson A, Balter P, Hanson W, Ibbott G. Experience with an IMRT head and neck QA phantom. Med. Phys. 29:1366, 2002.
103. Beach ML, Ibbott GS, Maryanski M. Implementation of a Polymer Gel Dosimetry Insert for an Anthropomorphic Head Phantom used to Evaluate Head and Neck Intensity-Modulated Radiation Therapy. Med. Phys. 29:1942, 2002.
104. Ibbott G, BenComo JA. Quality Assurance Measurements of Beam Parameters of a Linear Accelerator using MOSFET Dosimeters: A Feasibility Study. Med. Phys. 29:1201, 2002.
105. Lowenstein JR, Roll J, Hanson WF, Davis D, Lanciano R, Calkins AR, Petereit D, Varia M, Ibbott GS. Radiotherapy Quality Assurance of Gynecologic Oncology Group (GOG) Protocol 165, A Cooperative Group Study of Carcinoma of the Cervix. International Journal of Radiation Oncology Biology Physics 54:76A, 2002.
106. Cho SH, Ibbott GS. Reference Photon Dosimetry Data for the Siemens Primus Linear Accelerator: Preliminary Results for Depth Dose and Output Factor. Med. Phys. 29:1944, 2002.
107. Nath R, Rivard M, Coursey B, DeWerd L, Hanson W, Huq M, Ibbott G, Williamson J. Status of the American Association of Physicists in Medicine Radiation Therapy Committee’s Subcommittee on Low-Energy Interstitial Brachytherapy Source Dosimetry: Procedure for the Development of Consensus Single-Source Dose-Distributions. Med. Phys. 29:1349, 2002.
108. Aguirre JF, Tailor R, Ibbott G, Stovall M, Hanson W. Thermoluminescence Dosimetry as a tool for remote verification of output for radiotherapy beams: 25 years of experience. Standards and Codes of Practice in Medical Radiation Dosimetry 2:191-9, 2002.
109. Krintz A, Hanson WF, Ibbott GS, Followill DS. Verification of Plaque Simulator Dose Distributions using Radiochromic Film. Med. Phys. 29:1220-1, 2002.
110. Izewska J, Svensson H, Ibbott G. Worldwide QA networks for radiotherapy dosimetry. Standards and Codes of Practice in Medical Radiation Dosimetry 2:139-55, 2002.

Book Chapters
1. FitzGerald TJ, Bishop-Jodoin M, Urie M, Ulin K, Ibbott G, Purdy J, Saltz J, Peters L, Schnall M, Deasy J, Bosch W, Knopp M, Schwartz L, White K, Hanusik R, Kessel S, Morano K, Laurie F. Quality Assurance of Clinical Trials in the Management of Cancer in the Head and Neck. In: Head and Neck Cancer: Multimodality Management. Ed(s) Bernier J. In Press.
2. Ibbott G. QA for Clinical Dosimetry. with Emphasis on Clinical Trials. In: Clinical Dosimetry Measurements in Radiotherapy. Ed(s) DWO Rogers, JE Cygler. Medical Physics Publishing: Madison, 577-604, 2009.
3. Ibbott GS. Radiation Physics. In: Handbook of Radiation Oncology. Ed(s) Haffty BG, Wilson LD. Jones & Bartlett: Sudbury, 1-40, 2009.
4. Fitzgerald TJ, White K, Saltz J, Sharma A, Siegel E, Urie M, Ulin K, Purdy J, Bosch W, Matthews J, Deasy J, Ibbott G, Laurie F, Hanusik R, Yorty J, Bishop-Jodoin M, Kessel S, Cicchetti MG, McCarten K, Rosen N, Pieters R, Voss S, Reaman G, Schnall M, Schilsky R, Knopp M, Schwartz L, Baker L, Comis R, Kun L, boyett J, Ramamurthy U, Parliament M, Nelson H, Ota D. Development of a Queriable Database for Oncology Outcome Analysis. In: Cured II - LENT Cancer Survivorship Research and Education. Ed(s) P Rubin, SL Constine, LB Marks, P Okunieff. Springer: New York, 55-66, 2008.
5. Galvin JM, Ibbott GS. Commissioning and Accreditation of a Stereotactic Body Radiation Therapy Program. In: Stereotactic Body Radiation Therapy. Ed(s) Kavanagh BK, Timmerman RD. Lippincott Williams & Wilkins: Philadelphia, 85-93, 2005.
6. Ibbott GS. Radiation Dosimetry: 3-Dimensional. In: Encyclopedia of Medical Devices and Instrumentation. Ed(s) Webster JG. John Wiley & Sons: Hoboken, 481-500, 2005.
7. Ibbott GS. Professional Roles in VBT. In: Intravascular Brachytherapy Fluoroscopically Guided Interventions. Ed(s) Balter S, Chan RC, Shope TB. Medical Physics Publishing, 531-44, 2002.
8. Ibbott GS. What Every Medical Physicist Should Know about the JCAHO Standards. In: Accreditation Programs and the Medical Physicist. Ed(s) Dixon RL, Butler PF, Sobol WT. Medical Physics Publishing: Madison, 139-73, 2001.
9. Ibbott GS. Detectors for 2D or 3D Dosimetry Measurements. In: General Practice of Radiation Oncology Physics in the 21st Century. Ed(s) Shiu AS, Mellenberg DE. Medical Physics Publishing: Madison, 329-56, 2000.
10. Ibbott GS. Visualization and measurement of complex dose distributions using BANG TM polymer gel dosimeters. In: Medical Imaging and Precision and Therapy. Ed(s) Xie N-Z. The Foundation of International Scientific Exchange: Guangzhou, 144-62, 2000.
11. Ibbott GS. Brachytherapy treatment devices and treatment planning. In: Biomedical uses of radiation, part B: therapeutic applications. VCH Publishers: Weinheim, 1009-54, 1999.
12. Ibbott GS. Managed Care: What is it? The Projected Impact of Managed Care on Medical Physics. In: Introduction to the Professional Aspects of Medical Physics. Ed(s) Hogstrom KR, Horton JL. UT M.D. Anderson Cancer Center: Houston, 140-54, 1999.
13. Hendee WR, Rossi RP, Spitzer VM, Banjavic RL, Cacak RK, Ibbott GS. Identification of Clinical Needs. Preparation of Performance Specifications. Design of a Quality Assurance Program. Brief Description of Radiologic Modalities. In: The Selection and Performance of Radiologic Equipment. Ed(s) Hendee WR. Williams and Wilkins: Baltimore, 4-33, 40-84, 163-208, 225-254, 1985.

Books (edited and written)
1. Hendee WR, Ibbott GS, Hendee EG. Radiation Therapy Physics., 3rd. John Wiley and Sons: Hoboken, 2004.
2. Hendee WR Ibbott GS. Radiation Therapy Physics., 2nd. Mosby Year-Book Publishers: Philadelphia, 1996.

Letters to the Editor
1. Ibbott GS, Molineu A, Followill D. Multi-Institutional Trial of Accelerated Hypofractionated Intensity-Modulated Radiation Therapy for Early-Stage Oropharyngeal Cancer (RTOG 00-22). Int. J. of Radiation Oncology, Biol. Phys. 2/2010.
2. Butler WM, Huq MS, Li Z, Thomadsen BR, DeWerd LA, Ibbott GS, Mitch MG, Nath R, Rivard MJ, Williamson JF, Yue NJ, Zaider M. Third party brachytherapy seed calibrations and physicist responsibilities. Medical Physics 33(1):247-8, 2006. PMID: 16485431.
3. Nag S, Cardenas H, Chang S, Das IJ, Ibbott GS, Thomadsen B, Varia M. Reply to GEC-ESTRO-GYN letter. Int. J. of Radiation Oncology, Biol. Phys. 62:295-6, 2005.
4. Nag S, Cardenas H, Chang S, Das IJ, Ibbott GS, Lowenstein J, Roll J, Thomadsen B, Varia M. Reply to Narayan et. al. regarding ROB-D-05-00575. Int. J. of Radiation Oncology, Biol. Phys. 63:645-6, 2005.
5. Palta JR, Deye JA, Ibbott GS, Purdy JA, Urie MM . Credentialing of Institutions for IMRT in Clinical Trials. Int. J. of Radiation Oncology, Biol. Phys. 59(4):1257-62, 2004. PMID: 15234063.
6. Tailor R, Hanson W, Ibbott G. Reply to Comment on Calculated absorbed-dose ratios, TG51/TG21, for most widely used cylindrical and parallel-plate ion chambers over a range of photon and electron energies. Medical Physics 30:478-80, 2003.
7. Rivard MJ, Coursey BM, DeWerd LA, Hanson WF, Huq MS, Ibbott GS, Nath R, Williamson JF. Comment on abandoning geometry factors other than that of a point source in brachytherapy dosimetry. Medical Physics 29:1917-18, 2002.
8. Ibbott GS, Meigooni AS, Gearheart DM. Monte Carlo determination of dose rate constant. Medical Physics 29(7):1637-8, 2002. PMID: 12148747.
9. Ibbott GS, Nath R. Dose-rate constant for Imagyn 125I brachytherapy source. Med Phys 28(4):705, 4/2001. PMID: 11339770.
10. Ibbott GS. Reply to the Editor Concerning Radiation Therapy Treatment Planning and the Distortion of CT Images. Medical Physics 7:261, 1980.

Manuals, Teaching Aids, Other Teaching Publications
1. Ibbott G, Izewska J, Schmidt R, Shortt K, Van Dyk J, Vatnitsky S, Welleweerd J. IAEA TECDOC 1540, Specification and acceptance testing of radiotherapy treatment planning systems. IAEA: Vienna, 4/2007.
2. Olch A, Kline R, Ibbott G, Anderson JR, Deye J, Fitzgerald TJ, Followill D, Gillin MT, Huq MS, Palta JR, Purdy JA, Urie MM. Quality Assurance for Clinical Trials: A Primer for Physicists, Prepared by AAPM Subcommittee on QA for Clinical Trials. AAPM Report No. 86. 10/2004.
3. Ibbott GS. Report of the International Workshop on Safety Measures to Address the Year 2000 Issue at Medical Facilities Which Use Radiation Generators and Radioactive Materials. 6/1999.
4. Ibbott GS. IAEA TECDOC 1074, Safety measures to address the Year 2000 issue at medical facilities which use radiation generators and radioactive materials. International Atomic Energy Agency, 3/1999.
5. Thomadsen BR, Ibbott GS. Radiological Society of North America. RSNA Publications, 1997.
6. Miller DW, Bloch PH, Cunningham JR, Curran BH, Ibbott GS, Jones D, Jucius SZ, Leavitt DD, Mohan R, van de Geijn J. Task Group 23 of the Radiation Therapy Committee. American Association of Physicists in Medicine Report No. 55: Radiation Treatment Planning Dosimetry Verification. American Institute of Physics: Woodbury, NY, 8/1995.
7. Ibbott GS, Brezovich I, Fessenden P, Pipman Y, Sandhu T, Sathiaseelan V, Stauffer P, Galdi A, Saylor T. Performance Evaluation of Hyperthermia Equipment, AAPM Report No. 26. American Institute of Physics, 6/1989.

Grant & Contract Support

Title: Advanced Technology Radiation Therapy Quality Assurance Review Consortium
Funding Source: Washington University
Role: Principal Investigator-MDACC
Principal Investigator: Michalski
Duration: 7/1/2007 - 6/30/2012
 
Title: Accurate High Resolution 3D Dosimetry
Funding Source: Duke University
Role: Principal Investigator-MDACC
Principal Investigator: Oldham
Duration: 7/1/2007 - 6/30/2011
 
Title: Dosimetric Characterization of Cesium-131 Brachytherapy Sources
Funding Source: IsoRay Medical
Role: Consultant
Duration: 8/30/2006 - 8/30/2007
 
Title: Benchmark Beam Data: Improved Accuracy in Radiotherapy
Funding Source: Sun Nuclear Corporation
Role: Principal Investigator-MDACC
Principal Investigator: William Simon
Duration: 7/1/2006 - 6/30/2008
 
Title: Development of 3D Dosimetry for Radiotherapy
Funding Source: NIH
Role: Principal Investigator
Duration: 11/1/2005 - 10/31/2007
 
Title: Benchmark Beam Data: Improved Accuracy in Radiotherapy
Funding Source: Sun Nuclear Corporation
Role: Consultant
Principal Investigator: William Simon
Duration: 8/1/2005 - 3/14/2006
 
Title: The Radiological Physics Center
Funding Source: NIH
Role: Principal Investigator
Duration: 1/1/2005 - 12/31/2010
 
Title: Automated Verification System for Conformal RTP and IMRT
Funding Source: NIH
Role: Principal Investigator
Duration: 11/1/2004 - 10/31/2006
 
Title: Dosimetric Characterization of Pd-103 Brachytherapy Sources and Related Activities
Funding Source: ATI Medical Corporation
Role: Principal Investigator
Duration: 6/21/2002 - 6/30/2003
 
Title: Dosimetric Characterization of I-125 Brachytherapy Sources and Related Activities
Funding Source: Imagyn Medical Technologies
Role: Principal Investigator
Duration: 1/23/2002 - 1/31/2003
 
Title: Polymer Gel Dosimetry
Funding Source: Recruitment Start-Up Funds
Role: Principal Investigator
Duration: 9/1/2001 - 12/31/2004

Last updated: 2/19/2010