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Huang J, Followill D, Howell R, Liu X, Mirkovic D, Stingo F, Kry S. SU-E-T-329: Dosimetric Impact of Implementing Metal Artifact Reduction Methods and Metal Energy Deposition Kernels for Photon Dose Calculations. Med Phys 2015. [DOI: 10.1118/1.4924690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kerns J, Howell R, Followill D, Melancon A, Stingo F, Kry S. SU-E-T-792: Validation of a Secondary TPS for IROC-H Recalculation of Anthropomorphic Phantoms. Med Phys 2015. [DOI: 10.1118/1.4925156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Kry S, Howell R, Bednarz B. PO-1005: AAPM TG-158: assessing and lowering doses outside the treatment volume from external-beam radiation therapy. Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)40997-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mayo C, Miller R, Sloan J, Wu Q, Howell R. WE-G-9A-01: Radiation Oncology Outcomes Informatics. Med Phys 2014. [DOI: 10.1118/1.4889529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Huang J, Kerns J, Nute J, Liu X, Stingo F, Followill D, Mirkovic D, Howell R, Kry S. WE-D-18A-01: Evaluation of Three Commercial Metal Artifact Reduction Methods for CT Simulations in Radiation Therapy Treatment Planning. Med Phys 2014. [DOI: 10.1118/1.4889410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Starkschall G, Kry S, Howell R. MO-D-9A-01: “Stop Lecturing Me!” - New Methods for Teaching Medical Physics. Med Phys 2014. [DOI: 10.1118/1.4889145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Khan A, Robertson JD, Narra V, Yue N, Howell R. SU-E-T-193: FMEA Severity Scores - Do We Really Know? Med Phys 2014. [DOI: 10.1118/1.4888523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Pulliam K, Kerns J, Howell R, Followill D, O' Daniel J, Kry S. MO-G-BRE-02: A Survey of IMRT QA Practices for More Than 800 Institutions. Med Phys 2014. [DOI: 10.1118/1.4889185] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Wang X, Zhang X, Li X, Amos RA, Shaitelman SF, Hoffman K, Howell R, Salehpour M, Zhang SX, Sun TL, Smith B, Tereffe W, Perkins GH, Buchholz TA, Strom EA, Woodward WA. Accelerated partial-breast irradiation using intensity-modulated proton radiotherapy: do uncertainties outweigh potential benefits? Br J Radiol 2013; 86:20130176. [PMID: 23728947 PMCID: PMC3755395 DOI: 10.1259/bjr.20130176] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/22/2013] [Accepted: 05/29/2013] [Indexed: 11/07/2022] Open
Abstract
OBJECTIVE Passive scattering proton beam (PSPB) radiotherapy for accelerated partial-breast irradiation (APBI) provides superior dosimetry for APBI three-dimensional conformal photon radiotherapy (3DCRT). Here we examine the potential incremental benefit of intensity-modulated proton radiotherapy (IMPT) for APBI and compare its dosimetry with PSPB and 3DCRT. METHODS Two theoretical IMPT plans, TANGENT_PAIR and TANGENT_ENFACE, were created for 11 patients previously treated with 3DCRT APBI and were compared with PSPB and 3DCRT plans for the same CT data sets. The impact of range, motion and set-up uncertainties as well as scanned spot mismatching between fields of IMPT plans was evaluated. RESULTS IMPT plans for APBI were significantly better regarding breast skin sparing (p<0.005) and other normal tissue sparing than 3DCRT plans (p<0.01) with comparable target coverage (p=ns). IMPT plans were statistically better than PSPB plans regarding breast skin (p<0.002) and non-target breast (p<0.007) in higher dose regions but worse or comparable in lower dose regions. IMPT plans using TANGENT_ENFACE were superior to that using TANGENT_PAIR in terms of target coverage (p<0.003) and normal tissue sparing (p<0.05) in low-dose regions. IMPT uncertainties were demonstrated for multiple causes. Qualitative comparison of dose-volume histogram confidence intervals for IMPT suggests that numeric gains may be offset by IMPT uncertainties. CONCLUSION Using current clinical dosimetry, PSPB provides excellent dosimetry compared with 3DCRT with fewer uncertainties compared with IMPT. ADVANCES IN KNOWLEDGE As currently delivered in the clinic, PSPB planning for APBI provides as good or better dosimetry than IMPT with less uncertainty.
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Whetham J, Taylor S, Charlwood L, Keith T, Howell R, McInnes C, Payne E, Home J, White D, Gilleece Y. Pre-exposure prophylaxis for conception (PrEP-C) as a risk reduction strategy in HIV-positive men and HIV-negative women in the UK. AIDS Care 2013; 26:332-6. [PMID: 23876052 DOI: 10.1080/09540121.2013.819406] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Couples wishing to have biological children when one partner is HIV positive and the other is HIV negative present clinicians with complex clinical, social and ethical considerations. We established two multidisciplinary pre-conception services for HIV-positive individuals and their partners. We report the first UK use of pre-exposure prophylaxis for conception (PrEP-C) as part of an overall risk reduction strategy. Couples were counselled and written informed consent for PrEP-C was obtained. Patient demographics, HIV and medical histories were recorded. Males underwent baseline semen analysis and seminal HIV viral load testing. Females had full fertility screens. Both partners were screened for sexually transmitted infections. All couples used timed ovulatory intercourse (TOI). Tenofovir±emtricitabine was taken by the female at protocol designated times before±after TOI. Thirty-two male positive/female negative couples used the services. Thirteen couples have used PrEP-C (median age of male 41 years (range 32-56), female 31 (28-43); median CD4 533 (236-1194); all male plasma and seminal HIV viral loads were undetectable). Eleven pregnancies in 10 couples have resulted in 7 live births, 1 ongoing pregnancy and 4 miscarriages (5/40, 6/40, 10/40 and 1 twin 17/40) after a median of 2.5 attempts (range 1-5). PrEP-C was well tolerated with no discontinuations and no HIV transmissions. These data suggest that PrEP-C is a safe and effective option for serodiscordant couples wishing to conceive; a standardised protocol has been developed; data collection via a central database is under way.
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Howell R, Newhauser W, Burgett E. WE-E-141-08: Measurements of Secondary Neutron Spectrum and Dose Equivalent From a 250 MeV Passively Scattered Proton Beam Using An Extended Range Bonner Sphere Spectrometer. Med Phys 2013. [DOI: 10.1118/1.4815599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Wang X, Salehpour M, Howell R, Melancon A, Sun T, Woodward W, Smith B. SU-E-J-12: Evaluation of Setup Uncertainties for Electron Boost Field Treated Using Compression Device for Breast Cancer Irradiation. Med Phys 2013. [DOI: 10.1118/1.4814224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Eley J, Friedrich T, Homann K, Mahajan A, Durante M, Bert C, Howell R, Scholz M, Newhauser W. SU-E-T-278: Risk of Developing a Second Cancer in the Breast for Hodgkin Lymphoma Patients Receiving Carbon Ion Therapy Versus Proton Therapy. Med Phys 2013. [DOI: 10.1118/1.4814712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Huang J, Eklund D, Childress N, Howell R, Mirkovic D, Kry S. SU-E-T-554: Dosimetric Impact of Implementing Kernel Hardening and Material-Specific Kernels in the Convolution/Superposition Method. Med Phys 2013. [DOI: 10.1118/1.4814983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Zhang R, Howell R, Homann K, Giebeler A, Taddei P, Mahajan A, Newhauser W. SU-E-T-283; Risks of Cardiac Toxicity in Pediatric Patients Receiving Photon Or Proton Radiotherapy. Med Phys 2013. [DOI: 10.1118/1.4814717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Homann K, Newhauser W, Howell R, Eley J. SU-E-T-275: Voxelized Second Cancer Risk Calculation - Comparison of Proton and Photon Radiotherapies for Hodgkin Lymphoma. Med Phys 2013. [DOI: 10.1118/1.4814709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Han T, Tailor R, Melancon A, Howell R, Mourtada F, Salehpour M. SU-C-137-07: A Comprehensive Investigation of Dosimetric Uncertainties in Junction Region of Breast Superclavicular and Tangential Fields. Med Phys 2013. [DOI: 10.1118/1.4813938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Hobbs R, Sgouros G, Howell R. SU-E-J-184: A Dose-Independent Relative Biological Effect Quantity for Targeted Alpha-Particle Therapy in the EQD2 Formalism. Med Phys 2013. [DOI: 10.1118/1.4814396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Howell R, Kry S, Titt U. MO-F-134-02: Project-Based Learning - Expanding Course Content with a Broad-Scope Project. Med Phys 2013. [DOI: 10.1118/1.4815305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Jalbout W, Howell R, Newhauser W, Geara F, Khater N, Taddei P. Poster - Thur Eve - 36: Out-of-Field dose in craniospinal irradiation. Med Phys 2012; 39:4631. [PMID: 28516718 DOI: 10.1118/1.4740144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The risk of radiotherapy induced secondary cancer depends on the integral dose delivered to the patient where the dose delivered within the radiation field is accounted for, as well as dose to out-of-field organs from scattered and leakage radiation. While commercial treatment planning systems allow accurate determination of in-field dose, they are generally not capable of accurate out-of-field dose prediction. Secondary cancer risk is especially an issue in craniospinal treatments where involved patients are often children or young adults. In this work we therefore propose a mathematical model that accurately predicts out-of-field dose for patients treated by craniospinal irradiation at the American University of Beirut Medical Center. An anthropomorphic phantom was imaged, planned and treated, with thermoluminescent dosimeters inserted in the phantom at in-field and out-of-field locations. The measurements showed that our treatment planning system calculated accurately (within 2%) dose inside the field, but did not perform well at points just outside the field edge and consistently underestimated the dose at points further away from the field edge. From the out-of-field measured data, a model was developed that predicts out-of-field dose at a point in the patient based on the distance of that point to the treatment field edge. The developed model is of the double-gaussian type; it contains parameters that can be tuned to make it applicable in other centers where linac geometry and treatment techniques may differ.
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Casey K, Alvarez P, Lawyer A, Kry S, Howell R, Davidson S, Followill D. SU-E-T-81: Development and Implementation of a Remote Audit Tool for High Dose Rate (HDR) Ir-192 Brachytherapy Using Optically Stimulated Luminescence Dosimetry. Med Phys 2012. [DOI: 10.1118/1.4735138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Eley J, Graeff C, Lüchtenborg R, Durante M, Howell R, Newhauser W, Bert C. WE-G-213CD-01: 4D Optimization for Scanned Ion Beam Tracking Therapy for Moving Tumors. Med Phys 2012; 39:3970. [DOI: 10.1118/1.4736202] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Han T, Tailor R, LaNeave S, Howell R, Mourtada F, Salehpour M. SU-E-T-528: Appraisal of Acorus XB and Convolution Dose Algorithms in Field Junction of Breast Tangential/superclavicular Fields. Med Phys 2012; 39:3827. [DOI: 10.1118/1.4735617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Han T, Mourtada F, Repchak R, Tonigan J, Mikell J, Howell R, Salehpour M, Molineu A, Followill D. SU-E-T-519: Experimental Evaluation of Deterministic Acuros XB Radiation Transport Algorithm for Heterogeneity Dose Calculation Using the Radiological Physics Center's Lung Phantom. Med Phys 2012; 39:3825. [DOI: 10.1118/1.4735608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Homann K, Howell R, Giebeler A, Eley J, Randeniya K, Newhauser W. SU-C-BRB-01: Radiogenic Second Cancer Risk Differences in Female Hodgkin Lymphoma Patients Treated with Proton versus Photon Radiotherapies. Med Phys 2012. [DOI: 10.1118/1.4734618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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