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DeJongh DF, DeJongh EA, Rykalin V, DeFillippo G, Pankuch M, Best AW, Coutrakon G, Duffin KL, Karonis NT, Ordoñez CE, Sarosiek C, Schulte RW, Winans JR, Block AM, Hentz CL, Welsh JS. A comparison of proton stopping power measured with proton CT and x-ray CT in fresh postmortem porcine structures. Med Phys 2021; 48:7998-8009. [PMID: 34739140 PMCID: PMC8678357 DOI: 10.1002/mp.15334] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/05/2021] [Accepted: 10/22/2021] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Currently, calculations of proton range in proton therapy patients are based on a conversion of CT Hounsfield units of patient tissues into proton relative stopping power. Uncertainties in this conversion necessitate larger proximal and distal planned target volume margins. Proton CT can potentially reduce these uncertainties by directly measuring proton stopping power. We aim to demonstrate proton CT imaging with complex porcine samples, to analyze in detail three-dimensional regions of interest, and to compare proton stopping powers directly measured by proton CT to those determined from x-ray CT scans. METHODS We have used a prototype proton imaging system with single proton tracking to acquire proton radiography and proton CT images of a sample of porcine pectoral girdle and ribs, and a pig's head. We also acquired close in time x-ray CT scans of the same samples and compared proton stopping power measurements from the two modalities. In the case of the pig's head, we obtained x-ray CT scans from two different scanners and compared results from high-dose and low-dose settings. RESULTS Comparing our reconstructed proton CT images with images derived from x-ray CT scans, we find agreement within 1% to 2% for soft tissues and discrepancies of up to 6% for compact bone. We also observed large discrepancies, up to 40%, for cavitated regions with mixed content of air, soft tissue, and bone, such as sinus cavities or tympanic bullae. CONCLUSIONS Our images and findings from a clinically realistic proton CT scanner demonstrate the potential for proton CT to be used for low-dose treatment planning with reduced margins.
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Affiliation(s)
| | | | | | - Greg DeFillippo
- Northwestern Medicine Chicago Proton Center, Warrenville, Illinois, USA
| | - Mark Pankuch
- Northwestern Medicine Chicago Proton Center, Warrenville, Illinois, USA
| | - Andrew W Best
- Department of Physics, Northern Illinois University, DeKalb, Illinois, USA
| | - George Coutrakon
- Department of Physics, Northern Illinois University, DeKalb, Illinois, USA
| | - Kirk L Duffin
- Department of Computer Science, Northern Illinois University, DeKalb, Illinois, USA
| | - Nicholas T Karonis
- Department of Computer Science, Northern Illinois University, DeKalb, Illinois, USA
- Argonne National Laboratory, Data Science and Learning Division, Argonne, Illinois, USA
| | - Caesar E Ordoñez
- Department of Computer Science, Northern Illinois University, DeKalb, Illinois, USA
| | - Christina Sarosiek
- Department of Physics, Northern Illinois University, DeKalb, Illinois, USA
| | | | - John R Winans
- Department of Computer Science, Northern Illinois University, DeKalb, Illinois, USA
| | - Alec M Block
- Edward Hines Jr. VA Medical Center, Radiation Oncology Service, Hines, Illinois, USA
- Department of Radiation Oncology, Loyola University Stritch School of Medicine, Maywood, Illinois, USA
| | - Courtney L Hentz
- Edward Hines Jr. VA Medical Center, Radiation Oncology Service, Hines, Illinois, USA
- Department of Radiation Oncology, Loyola University Stritch School of Medicine, Maywood, Illinois, USA
| | - James S Welsh
- Edward Hines Jr. VA Medical Center, Radiation Oncology Service, Hines, Illinois, USA
- Department of Radiation Oncology, Loyola University Stritch School of Medicine, Maywood, Illinois, USA
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Fiedler DA, Hoffman S, Roeske JC, Hentz CL, Small W, Kang H. Dosimetric assessment of brass mesh bolus and transparent polymer-gel type bolus for commonly used breast treatment delivery techniques. Med Dosim 2021; 46:e10-e14. [PMID: 33536152 DOI: 10.1016/j.meddos.2021.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/08/2020] [Accepted: 01/05/2021] [Indexed: 11/29/2022]
Abstract
We investigated skin dose enhancements of brass mesh bolus (BMB) and a recently developed transparent polymer-gel bolus (PGB) for clinically relevant breast treatment delivery techniques. The dose enhancement of the breast surface with BMB and PGB were compared to that of tissue-equivalent bolus. Three breast treatment plans were generated on CT scans of an anthropomorphic chest phantom: tangential step-and-shoot 3D conformal (3DCRT) planned using Field-in-Field (FiF), tangential sliding-window 3DCRT using Electronic Compensator (EC), and volumetric modulated arc therapy (VMAT). All plans were created using 6 MV photons and a prescription dose (Rx) of 180 cGy per fraction. Skin doses of all 3 plans were measured with radiochromic films, separately delivered in triplicate. Each plan was delivered to the phantom without bolus, and then with BMB (1 or 2 layers; 3 or 10 mm tissue-equivalent), PGB, and Superflab (3, 5, and 10 mm tissue-equivalent). Doses were determined by reading the radiochromic films with a flatbed scanner, and analyzing the images using a calibration curve for each specific batch. For all bolus types and plans, surface doses averaged over the 3 measurements were between 88.4% and 107.4% of Rx. Without bolus, average measured skin doses were between 51.2% and 64.2% of Rx. Skin doses with BMB and PGB were comparable to that with tissue-equivalent bolus. Over all 3 treatment delivery techniques, using BMB resulted in average skin doses of 92.8% and 102.1% for 1- and 2 layers, respectively, and using PGB results in average skin doses of 94.8%, 98.2%, and 99.7% for 3, 5, and 10-mm tissue-equivalent, respectively. The average measured skin doses with BMB and PGB agreed within ± 3% compared to the tissue-equivalent thickness bolus. We concluded that BMB and PGB are clinically equivalent in skin dose enhancement for breast treatment as the 3, 5, and 10 mm tissue-equivalent bolus.
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Affiliation(s)
- Derek A Fiedler
- Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL, 60637 USA
| | - Sabrina Hoffman
- Department of Radiation Oncology, Loyola University Medical Center, Maywood, IL, 60637 USA
| | - John C Roeske
- Department of Radiation Oncology, Stritch School of Medicine, Cardinal Bernardine Cancer Center, Loyola University Chicago, Maywood, IL, 60637 USA
| | - Courtney L Hentz
- Department of Radiation Oncology, Stritch School of Medicine, Cardinal Bernardine Cancer Center, Loyola University Chicago, Maywood, IL, 60637 USA
| | - William Small
- Department of Radiation Oncology, Stritch School of Medicine, Cardinal Bernardine Cancer Center, Loyola University Chicago, Maywood, IL, 60637 USA
| | - Hyejoo Kang
- Department of Radiation Oncology, Stritch School of Medicine, Cardinal Bernardine Cancer Center, Loyola University Chicago, Maywood, IL, 60637 USA.
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Small W, Bosch WR, Harkenrider MM, Strauss JB, Abu-Rustum N, Albuquerque KV, Beriwal S, Creutzberg CL, Eifel PJ, Erickson BA, Fyles AW, Hentz CL, Jhingran A, Klopp AH, Kunos CA, Mell LK, Portelance L, Powell ME, Viswanathan AN, Yacoub JH, Yashar CM, Winter KA, Gaffney DK. NRG Oncology/RTOG Consensus Guidelines for Delineation of Clinical Target Volume for Intensity Modulated Pelvic Radiation Therapy in Postoperative Treatment of Endometrial and Cervical Cancer: An Update. Int J Radiat Oncol Biol Phys 2020; 109:413-424. [PMID: 32905846 DOI: 10.1016/j.ijrobp.2020.08.061] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/01/2020] [Accepted: 08/29/2020] [Indexed: 01/06/2023]
Abstract
PURPOSE Accurate target definition is critical for the appropriate application of radiation therapy. In 2008, the Radiation Therapy Oncology Group (RTOG) published an international collaborative atlas to define the clinical target volume (CTV) for intensity modulated pelvic radiation therapy in the postoperative treatment of endometrial and cervical cancer. The current project is an updated consensus of CTV definitions, with removal of all references to bony landmarks and inclusion of the para-aortic and inferior obturator nodal regions. METHODS AND MATERIALS An international consensus guideline working group discussed modifications of the current atlas and areas of controversy. A document was prepared to assist in contouring definitions. A sample case abdominopelvic computed tomographic image was made available, on which experts contoured targets. Targets were analyzed for consistency of delineation using an expectation-maximization algorithm for simultaneous truth and performance level estimation with kappa statistics as a measure of agreement between observers. RESULTS Sixteen participants provided 13 sets of contours. Participants were asked to provide separate contours of the following areas: vaginal cuff, obturator, internal iliac, external iliac, presacral, common iliac, and para-aortic regions. There was substantial agreement for the common iliac region (sensitivity 0.71, specificity 0.981, kappa 0.64), moderate agreement in the external iliac, para-aortic, internal iliac and vaginal cuff regions (sensitivity 0.66, 0.74, 0.62, 0.59; specificity 0.989, 0.966, 0.986, 0.976; kappa 0.60, 0.58, 0.52, 0.47, respectively), and fair agreement in the presacral and obturator regions (sensitivity 0.55, 0.35; specificity 0.986, 0.988; kappa 0.36, 0.21, respectively). A 95% agreement contour was smoothed and a final contour atlas was produced according to consensus. CONCLUSIONS Agreement among the participants was most consistent in the common iliac region and least in the presacral and obturator nodal regions. The consensus volumes formed the basis of the updated NRG/RTOG Oncology postoperative atlas. Continued patterns of recurrence research are encouraged to refine these volumes.
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Affiliation(s)
- William Small
- Loyola University Stritch School of Medicine, Maywood, Illinois.
| | - Walter R Bosch
- Washington University School of Medicine, St. Louis, Missouri
| | | | | | | | | | | | | | | | - Beth A Erickson
- Froedtert and the Medical College of Wisconsin, Milwuakee, Wisconsin
| | - Anthony W Fyles
- Princess Margaret Cancer Center, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | | | - Loren K Mell
- UC San Diego Moores Cancer Center, La Jolla, California
| | | | | | | | - Joseph H Yacoub
- Loyola University Stritch School of Medicine, Maywood, Illinois
| | | | - Kathryn A Winter
- NRG Oncology Statistics and Data Management Center, Philadelphia, Pennsylvania
| | - David K Gaffney
- Huntsman Cancer Institute/University of Utah, Salt Lake City, Utah
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Aihara E, Hentz CL, Korman AM, Perry NPJ, Prasad V, Shull GE, Montrose MH. In vivo epithelial wound repair requires mobilization of endogenous intracellular and extracellular calcium. J Biol Chem 2013; 288:33585-33597. [PMID: 24121509 DOI: 10.1074/jbc.m113.488098] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
We report that a localized intracellular and extracellular Ca(2+) mobilization occurs at the site of microscopic epithelial damage in vivo and is required to mediate tissue repair. Intravital confocal/two-photon microscopy continuously imaged the surgically exposed stomach mucosa of anesthetized mice while photodamage of gastric epithelial surface cells created a microscopic lesion that healed within 15 min. Transgenic mice with an intracellular Ca(2+)-sensitive protein (yellow cameleon 3.0) report that intracellular Ca(2+) selectively increases in restituting gastric epithelial cells adjacent to the damaged cells. Pretreatment with U-73122, indomethacin, 2-aminoethoxydiphenylborane, or verapamil inhibits repair of the damage and also inhibits the intracellular Ca(2+) increase. Confocal imaging of Fura-Red dye in luminal superfusate shows a localized extracellular Ca(2+) increase at the gastric surface adjacent to the damage that temporally follows intracellular Ca(2+) mobilization. Indomethacin and verapamil also inhibit the luminal Ca(2+) increase. Intracellular Ca(2+) chelation (1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxymethyl ester, BAPTA/AM) fully inhibits intracellular and luminal Ca(2+) increases, whereas luminal calcium chelation (N-(2-hydroxyetheyl)-ethylendiamin-N,N,N'-triacetic acid trisodium, HEDTA) blocks the increase of luminal Ca(2+) and unevenly inhibits late-phase intracellular Ca(2+) mobilization. Both modes of Ca(2+) chelation slow gastric repair. In plasma membrane Ca-ATPase 1(+/-) mice, but not plasma membrane Ca-ATPase 4(-/-) mice, there is slowed epithelial repair and a diminished gastric surface Ca(2+) increase. We conclude that endogenous Ca(2+), mobilized by signaling pathways and transmembrane Ca(2+) transport, causes increased Ca(2+) levels at the epithelial damage site that are essential to gastric epithelial cell restitution in vivo.
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Affiliation(s)
- Eitaro Aihara
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio 45267
| | - Courtney L Hentz
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio 45267
| | - Abraham M Korman
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio 45267
| | - Nicholas P J Perry
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio 45267
| | - Vikram Prasad
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267
| | - Gary E Shull
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, Ohio 45267
| | - Marshall H Montrose
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio 45267.
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