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Zhen H, Hrycushko B, Pompos A, Foster R, Yan Y, Stojadinovic S, Solberg T, Gu X. SU-E-T-556: Verification and Evaluation of Acuros XB Dose Calculations for Stereotactic Ablative Radiotherapy of the Thoracic Spine. Med Phys 2013. [DOI: 10.1118/1.4814985] [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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Pidikiti R, Stojadinovic S, Song K, Speiser M, Solberg T. WE-E-108-06: Demonstration of a CBCT Based Monte Carlo Model for Small Animal Treatment Planning. Med Phys 2013. [DOI: 10.1118/1.4815584] [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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Pidikiti R, Stojadinovic S, Song K, Speiser M, Solberg T. WE-E-108-05: Evaluation of the XRAD 225Cx MC Source Model in Heterogeneous Mediums. Med Phys 2013. [DOI: 10.1118/1.4815583] [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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Pidikiti R, Stojadinovic S, Kwang S, Speiser M, Solberg T. OC-0063: Commissioning CBCT based Monte Carlo treatment planning system for small animal stereotactic irradiation. Radiother Oncol 2013. [DOI: 10.1016/s0167-8140(15)32369-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Desrosiers M, DeWerd L, Deye J, Lindsay P, Murphy MK, Mitch M, Macchiarini F, Stojadinovic S, Stone H. The Importance of Dosimetry Standardization in Radiobiology. JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY 2013; 118:403-18. [PMID: 26401441 PMCID: PMC4487307 DOI: 10.6028/jres.118.021] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/17/2013] [Indexed: 05/14/2023]
Abstract
Radiation dose is central to much of radiobiological research. Precision and accuracy of dose measurements and reporting of the measurement details should be sufficient to allow the work to be interpreted and repeated and to allow valid comparisons to be made, both in the same laboratory and by other laboratories. Despite this, a careful reading of published manuscripts suggests that measurement and reporting of radiation dosimetry and setup for radiobiology research is frequently inadequate, thus undermining the reliability and reproducibility of the findings. To address these problems and propose a course of action, the National Cancer Institute (NCI), the National Institute of Allergy and Infectious Diseases (NIAID), and the National Institute of Standards and Technology (NIST) brought together representatives of the radiobiology and radiation physics communities in a workshop in September, 2011. The workshop participants arrived at a number of specific recommendations as enumerated in this paper and they expressed the desirability of creating dosimetry standard operating procedures (SOPs) for cell culture and for small and large animal experiments. It was also felt that these SOPs would be most useful if they are made widely available through mechanism(s) such as the web, where they can provide guidance to both radiobiologists and radiation physicists, be cited in publications, and be updated as the field and needs evolve. Other broad areas covered were the need for continuing education through tutorials at national conferences, and for journals to establish standards for reporting dosimetry. This workshop did not address issues of dosimetry for studies involving radiation focused at the sub-cellular level, internally-administered radionuclides, biodosimetry based on biological markers of radiation exposure, or dose reconstruction for epidemiological studies.
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Ma S, Richardson J, Bitmansour A, Solberg T, Pidikiti R, Song K, Stojadinovic S, Vitetta E, Meyer J. Depletion of Regulatory T Cells Does Not Influence the Inflammatory Response Induced by High-dose Irradiation. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.1842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Stojadinovic S, Ouyang L, Bao Q, Pompos A, Gu X, Solberg T. Gamma Analysis of Normalized and Un-normalized Dose Distributions. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.2157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Pidikiti R, Stojadinovic S, Song K, Speiser M, Solberg T. SU-E-T-274: Monte Carlo Simulations of Output Factors for a Small Animal Irradiator. Med Phys 2012; 39:3766. [DOI: 10.1118/1.4735342] [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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Stojadinovic S, Luo O, Bao Q, Pompos A, Gu X, Solberg T. SU-E-T-386: Gamma Analysis of Normalized and Un-Normalized Dose Distributions. Med Phys 2012; 39:3793. [PMID: 28517202 DOI: 10.1118/1.4735475] [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
PURPOSE The gamma index method, as currently implemented in all commercial QA software, calls for selection of a normalization point to evaluate agreement between two dose distributions. The implication of this is that there is an infinite number of possible solutions! Which one to pick? A unique and more relevant solution is obtained only if no normalization point is used. METHODS AND MATERIALS The set of test cases suggested by the AAPM TG1 19 were planned using Pinnacle 8.0m and delivered on a Varian 21EX linac for 6 and 18 MV photons. The recommended point and planar dose measurements were obtained using a Pinpoint ion chamber, EDR2 film and MatriXX. The gamma index method using typical 3%, 3 mm criteria with and without a normalization point was used to assess the agreement between calculated and delivered planar dose distributions. The analysis was extended to a set of data for clinically treated patients. RESULTS The comparison with the TG119 benchmark data showed that all point dose and planar measurements for 6 MV were within the published range. Similar results, although without published data to compare with, were obtained for 18 MV as well. For all complex tests, the percentage of points passing the gamma criteria of 3%, 3 mm was (95.8±1.6)% and (95.6±1.0)% for 6 MV and 18 MV, respectively. Without a normalization point, however, the same gamma analysis fell to (20.7±6.7)% and (13.9±4.0)% for 6 MV and 18 MV, respectively. The clinical data set showed the same trend, with the gamma passing rate declining from (98.9±0.7)% to (33.4±13.1)%. CONCLUSION The gamma index method provides a unique answer for gamma passing rate only without normalizing dose distributions to any particular point. The common gamma criteria of 3%, 3 mm, however, is a very poor metric in that case.
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Rifkin LH, Stojadinovic S, Stewart CH, Song KH, Maxted MC, Bell MH, Kashefi NS, Speiser MP, Saint-Cyr M, Story MD, Rohrich RJ, Brown SA, Solberg TD. An athymic rat model of cutaneous radiation injury designed to study human tissue-based wound therapy. Radiat Oncol 2012; 7:68. [PMID: 22568958 PMCID: PMC3403853 DOI: 10.1186/1748-717x-7-68] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 05/08/2012] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To describe a pilot study for a novel preclinical model used to test human tissue-based therapies in the setting of cutaneous radiation injury. METHODS A protocol was designed to irradiate the skin of athymic rats while sparing the body and internal organs by utilizing a non-occlusive skin clamp along with an x-ray image guided stereotactic irradiator. Each rat was irradiated both on the right and the left flank with a circular field at a 20 cm source-to-surface distance (SSD). Single fractions of 30.4 Gy, 41.5 Gy, 52.6 Gy, 65.5 Gy, and 76.5 Gy were applied in a dose-finding trial. Eight additional wounds were created using the 41.5 Gy dose level. Each wound was photographed and the percentage of the irradiated area ulcerated at given time points was analyzed using ImageJ software. RESULTS No systemic or lethal sequelae occurred in any animals, and all irradiated skin areas in the multi-dose trial underwent ulceration. Greater than 60% of skin within each irradiated zone underwent ulceration within ten days, with peak ulceration ranging from 62.1% to 79.8%. Peak ulceration showed a weak correlation with radiation dose (r = 0.664). Mean ulceration rate over the study period is more closely correlated to dose (r = 0.753). With the highest dose excluded due to contraction-related distortions, correlation between dose and average ulceration showed a stronger relationship (r = 0.895). Eight additional wounds created using 41.5 Gy all reached peak ulceration above 50%, with all healing significantly but incompletely by the 65-day endpoint. CONCLUSIONS We developed a functional preclinical model which is currently used to evaluate human tissue-based therapies in the setting of cutaneous radiation injury. Similar models may be widely applicable and useful the development of novel therapies which may improve radiotherapy management over a broad clinical spectrum.
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Pidikiti R, Stojadinovic S, Speiser M, Song KH, Hager F, Saha D, Solberg TD. Dosimetric characterization of an image-guided stereotactic small animal irradiator. Phys Med Biol 2011; 56:2585-99. [PMID: 21444969 DOI: 10.1088/0031-9155/56/8/016] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Small animal irradiation provides an important tool used by preclinical studies to assess and optimize new treatment strategies such as stereotactic ablative radiotherapy. Characterization of radiation beams that are clinically and geometrically scaled for the small animal model is uniquely challenging for orthovoltage energies and minute field sizes. The irradiator employs a commercial x-ray device (XRAD 320, Precision x-ray, Inc.) with a custom collimation system to produce 1-10 mm diameter beams and a 50 mm reference beam. Absolute calibrations were performed using the AAPM TG-61 methodology. Beam's half-value layer (HVL) and timer error were measured with an ionization chamber. Percent depth dose (PDD), output factors (OFs) and off-axis ratios were measured using radiochromic film, a diode and a pinpoint ionization chamber at 19.76 and 24.76 cm source-to-surface distance (SSD). PDD measurements were also compared with Monte Carlo (MC) simulations. In-air and in-water absolute calibrations for the reference 50 mm diameter collimator at 19.76 cm SSD were measured as 20.96 and 20.79 Gy min(-1), respectively, agreeing within 0.8%. The HVL at 250 kVp and 15 mAs was measured to be 0.45 mm Cu. The reference field PDD MC simulation results agree with measured data within 3.5%. PDD data demonstrate typical increased penetration with increasing field size and SSD. For collimators larger than 5 mm in diameter, OFs measured using film, an ion chamber and a diode were within 3% agreement.
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Song KH, Pidikiti R, Stojadinovic S, Speiser M, Seliounine S, Saha D, Solberg TD. An x-ray image guidance system for small animal stereotactic irradiation. Phys Med Biol 2010; 55:7345-62. [DOI: 10.1088/0031-9155/55/23/011] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Pidikiti R, Stojadinovic S, Speiser M, Song K, Solberg T. TH-C-204B-08: Energy Dependency and Dosimetric Modeling in Small Animal Stereotactic Irradiaton. Med Phys 2010. [DOI: 10.1118/1.4794896] [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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Song K, Pidikiti R, Stojadinovic S, Speiser M, Seliounine S, Saha D, Solberg T. SU-GG-J-06: Optical and X-Ray Image Guided Stereotactic Body Irradiator Dedicated to Small Animals. Med Phys 2010. [DOI: 10.1118/1.3468229] [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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Pidikiti R, Stojadinovic S, Song K, Speiser M, Seliounine S, Saha D, Solberg T. Dosimetric Characterization of Stereotactic Small Animal Irradiator. Int J Radiat Oncol Biol Phys 2009. [DOI: 10.1016/j.ijrobp.2009.07.1532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abolfath M, Papiez L, Stojadinovic S, Solberg T. SU-FF-T-483: Optical Enhancement of DNA-Base Radio-Resistivity. Med Phys 2009. [DOI: 10.1118/1.3181981] [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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Pidikiti R, Stojadinovic S, Song K, Seliounine S, Speiser M, Saha D, Solberg T. TH-C-BRC-04: Small Animal Stereotactic Irradiator. Med Phys 2009. [DOI: 10.1118/1.3182618] [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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Speiser M, Pidikiti R, Stojadinovic S, Song K, Solberg T. SU-FF-J-157: A Monte Carlo Model for Small Animal Stereotactic Irradiation. Med Phys 2009. [DOI: 10.1118/1.3181450] [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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Solberg T, Pidikiti R, Song K, Speiser M, Stojadinovic S, Saha D, Seliounine S. TU-C-BRD-04: Development and Application of a Pre-Clinical Stereotactic Irradiator. Med Phys 2009. [DOI: 10.1118/1.3182322] [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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Kiehl EL, Stojadinovic S, Malinowski KT, Limbrick D, Jost SC, Garbow JR, Rubin JB, Deasy JO, Khullar D, Izaguirre EW, Parikh PJ, Low DA, Hope AJ. Feasibility of small animal cranial irradiation with the microRT system. Med Phys 2008; 35:4735-43. [PMID: 18975718 DOI: 10.1118/1.2977762] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To develop and validate methods for small-animal CNS radiotherapy using the microRT system. MATERIALS AND METHODS A custom head immobilizer was designed and built to integrate with a pre-existing microRT animal couch. The Delrin couch-immobilizer assembly, compatible with multiple imaging modalities (CT, microCT, microMR, microPET, microSPECT, optical), was first imaged via CT in order to verify the safety and reproducibility of the immobilization method. Once verified, the subject animals were CT-scanned while positioned within the couch-immobilizer assembly for treatment planning purposes. The resultant images were then imported into CERR, an in-house-developed research treatment planning system, and registered to the microRTP treatment planning space using rigid registration. The targeted brain was then contoured and conformal radiotherapy plans were constructed for two separate studies: (1) a whole-brain irradiation comprised of two lateral beams at the 90 degree and 270 degree microRT treatment positions and (2) a hemispheric (left-brain) irradiation comprised of a single A-P vertex beam at the 0 degree microRT treatment position. During treatment, subject animals (n=48) were positioned to the CERR-generated treatment coordinates using the three-axis microRT motor positioning system and were irradiated using a clinical Ir-192 high-dose-rate remote after-loading system. The radiation treatment course consisted of 5 Gy fractions, 3 days per week. 90% of the subjects received a total dose of 30 Gy and 10% received a dose of 60 Gy. RESULTS Image analysis verified the safety and reproducibility of the immobilizer. CT scans generated from repeated reloading and repositioning of the same subject animal in the couch-immobilizer assembly were fused to a baseline CT. The resultant analysis revealed a 0.09 mm average, center-of-mass translocation and negligible volumetric error in the contoured, murine brain. The experimental use of the head immobilizer added 0.1 mm to microRT spatial uncertainty along each axis. Overall, the total spatial uncertainty for the prescribed treatments was +/-0.3 mm in all three axes, a 0.2 mm functional improvement over the original version of microRT. Subject tolerance was good, with minimal observed side effects and a low procedure-induced mortality rate. Throughput was high, with average treatment times of 7.72 and 3.13 min/animal for the whole-brain and hemispheric plans, respectively (dependent on source strength). CONCLUSIONS The method described exhibits conformality more in line with the size differential between human and animal patients than provided by previous prevalent approaches. Using pretreatment imaging and microRT-specific treatment planning, our method can deliver an accurate, conformal dose distribution to the targeted murine brain (or a subregion of the brain) while minimizing excess dose to the surrounding tissue. Thus, preclinical animal studies assessing the radiotherapeutic response of both normal and malignant CNS tissue to complex dose distributions, which closer resemble human-type radiotherapy, are better enabled. The procedural and mechanistic framework for this method logically provides for future adaptation into other murine target organs or regions.
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Cuttino L, Stojadinovic S, Shumadine J, Rosu M, Todor D, Arthur D. Potential Effect of Inherent Treatment Planning Uncertainties on Expected Vs. Actual Dose to Skin and Chest Wall with the Mammosite (MS) for Accelerated Partial Breast Irradiation. Int J Radiat Oncol Biol Phys 2008. [DOI: 10.1016/j.ijrobp.2008.06.758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Stojadinovic S, Belca I, Tadic M, Kasalica B, Nedic Z, Zekovic L. Galvanoluminescence properties of porous oxide films formed by anodization of aluminum in malonic acid. J Electroanal Chem (Lausanne) 2008. [DOI: 10.1016/j.jelechem.2008.03.022] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Stojadinovic S, Todor D, Cuttino L, Arthur D. TH-C-AUD A-01: A Systematic Analysis of Errors and Uncertainties in Partial Breast Irradiation Using the MammoSite Balloon Catheter. Med Phys 2008. [DOI: 10.1118/1.2962836] [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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Izaguirre EW, Diao X, Stojadinovic S, Mutic S, Khullar D, Deasy J, Parikh P, Hope A, Grigsby P, Low DA. TH-C-351-01: Design of the Washington University Small Animal Conformal Micro Irradiator. Med Phys 2008. [DOI: 10.1118/1.2962857] [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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Low D, Izaguirre E, Deasy J, Mutic S, Hope A, Stojadinovic S, Diao X, Grigsby P. TU-C-AUD C-03: Teletherapy MicroRT Using a Commercial 192Ir Source. Med Phys 2008. [DOI: 10.1118/1.2962449] [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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