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Van Dijk I, Visser J, Wiersma J, Van Boggelen J, Balgobind B, Feijen L, Huijskens S, Kremer L, Rasch C, Bel A. EP-1379: Heart volume reduction in paediatric cancer patients during radiotherapy. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31814-5] [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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Crama K, Houweling A, Visser J, Fukata K, Rasch C, Ohno T, Bel A, Van der Horst A. OC-0354: Dosimetric impact of anatomical changes in photon and particle therapy for pancreatic cancer. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)30796-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Seravalli E, Bosman M, Smyth G, Alapetite C, Christiaens M, Gandola L, Hoeben B, Horan G, Koutsouveli E, Kusters M, Lassen Y, Losa S, Magelssen H, Marchant T, Mandeville H, Oldenburger F, Padovani L, Paraskevopoulou C, Rombi B, Visser J, Whitfield G, Schwarz M, Vestergaard A, Janssens G. OC-0345: Comparing cranio spinal irradiation planning for photon and proton techniques at 15 European centers. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)30787-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Huijskens SC, van Dijk IW, Visser J, Rasch CR, Alderliesten T, Bel A. Magnitude and variability of respiratory-induced diaphragm motion in children during image-guided radiotherapy. Radiother Oncol 2017; 123:263-269. [DOI: 10.1016/j.radonc.2017.03.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/15/2017] [Accepted: 03/13/2017] [Indexed: 12/25/2022]
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De Jong R, Van Wieringen N, Visser J, Wiersma J, Crama K, Geijsen D, Lutkenhaus L, Bel A. OC-0356: Adaptive strategy for rectal cancer: evaluation of plan selection of the first 20 clinical patients. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)30798-3] [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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Houweling AC, Crama K, Visser J, Fukata K, Rasch CRN, Ohno T, Bel A, van der Horst A. Comparing the dosimetric impact of interfractional anatomical changes in photon, proton and carbon ion radiotherapy for pancreatic cancer patients. Phys Med Biol 2017; 62:3051-3064. [PMID: 28252445 DOI: 10.1088/1361-6560/aa6419] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Radiotherapy using charged particles is characterized by a low dose to the surrounding healthy organs, while delivering a high dose to the tumor. However, interfractional anatomical changes can greatly affect the robustness of particle therapy. Therefore, we compared the dosimetric impact of interfractional anatomical changes (i.e. body contour differences and gastrointestinal gas volume changes) in photon, proton and carbon ion therapy for pancreatic cancer patients. In this retrospective planning study, photon, proton and carbon ion treatment plans were created for 9 patients. Fraction dose calculations were performed using daily cone-beam CT (CBCT) images. To this end, the planning CT was deformably registered to each CBCT; gastrointestinal gas volumes were delineated on the CBCTs and copied to the deformed CT. Fraction doses were accumulated rigidly. To compare planned and accumulated dose, dose-volume histogram (DVH) parameters of the planned and accumulated dose of the different radiotherapy modalities were determined for the internal gross tumor volume, internal clinical target volume (iCTV) and organs-at-risk (OARs; duodenum, stomach, kidneys, liver and spinal cord). Photon plans were highly robust against interfractional anatomical changes. The difference between the planned and accumulated DVH parameters for the photon plans was less than 0.5% for the target and OARs. In both proton and carbon ion therapy, however, coverage of the iCTV was considerably reduced for the accumulated dose compared with the planned dose. The near-minimum dose ([Formula: see text]) of the iCTV reduced with 8% for proton therapy and with 10% for carbon ion therapy. The DVH parameters of the OARs differed less than 3% for both particle modalities. Fractionated radiotherapy using photons is highly robust against interfractional anatomical changes. In proton and carbon ion therapy, such changes can severely reduce the dose coverage of the target.
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Benčina M, Štaudohar M, Panneman H, Ruijter GJ, Visser J, Legiša M, Hammerschmid M, Neuper I, Konopitzky K, Bayer K, Josić D, Kovács KL, Rákhely G, Pott AS, Takács M, Tóth A, Bratu H, Gyõrfi K, Fodor B, Tusz J, Dahl C, Legiša M, Benčina M, Gradišnik-Grapulin M, Lukančič I, Kraševec N, Svetina M, Komel R, Podgornik A, Barut M, Strancar A, Josić D, Koloini T, Gaberc-Porekar V, Menart V, Zhu HY, Petrovič N, Ling KS, Gonsalves D. Abstracts. Pflugers Arch 2016. [DOI: 10.1007/s004240000102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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83
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Stevenson C, Blaauw R, Fredericks E, Visser J, Roux S. SUN-P140: Nutrient Intakes and the Validity and Reliability of Dietary Data in Irritable Bowel Syndrome Patients. Clin Nutr 2016. [DOI: 10.1016/s0261-5614(16)30483-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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84
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Biegun A, Takatsu J, Nakaji T, van Goethem MJ, van der Graaf E, Koffeman E, Visser J, Brandenburg S. Effect of scattering angle on energy loss radiography imaging for various proton energies relevant in proton therapy: A simulation study. Phys Med 2016. [DOI: 10.1016/j.ejmp.2016.07.462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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de Jong R, Lutkenhaus L, van Wieringen N, Visser J, Wiersma J, Crama K, Geijsen D, Bel A. Plan selection strategy for rectum cancer patients: An interobserver study to assess clinical feasibility. Radiother Oncol 2016; 120:207-11. [DOI: 10.1016/j.radonc.2016.07.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 07/21/2016] [Accepted: 07/22/2016] [Indexed: 10/21/2022]
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van de Schoot AJAJ, de Boer P, Crama KF, Visser J, Stalpers LJA, Rasch CRN, Bel A. Dosimetric advantages of proton therapy compared with photon therapy using an adaptive strategy in cervical cancer. Acta Oncol 2016; 55:892-9. [PMID: 26934821 DOI: 10.3109/0284186x.2016.1139179] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Background Image-guided adaptive proton therapy (IGAPT) can potentially be applied to take into account interfraction motion while limiting organ at risk (OAR) dose in cervical cancer radiation therapy (RT). In this study, the potential dosimetric advantages of IGAPT compared with photon-based image-guided adaptive RT (IGART) were investigated. Material and methods For 13 cervical cancer patients, full and empty bladder planning computed tomography (CT) images and weekly CTs were acquired. Based on both primary clinical target volumes (pCTVs) [i.e. gross tumor volume (GTV), cervix, corpus-uterus and upper part of the vagina] on planning CTs, the pretreatment observed full range primary internal target volume (pITV) was interpolated to derive pITV subranges. Given corresponding ITVs (i.e. pITVs including lymph nodes), patient-specific photon and proton plan libraries were generated. Using all weekly CTs, IGART and IGAPT treatments were simulated by selecting library plans and recalculating the dose. For each recalculated IGART and IGAPT fraction, CTV (i.e. pCTV including lymph nodes) coverage was assessed and differences in fractionated substitutes of dose-volume histogram (DVH) parameters (V15Gy, V30Gy, V45Gy, Dmean, D2cc) for bladder, bowel and rectum were tested for significance (Wilcoxon signed-rank test). Also, differences in toxicity-related DVH parameters (rectum V30Gy, bowel V45Gy) were approximated based on accumulated dose distributions. Results In 92% (96%) of all recalculated IGAPT (IGART) fractions adequate CTV coverage (V95% >98%) was obtained. All dose parameters for bladder, bowel and rectum, except the fractionated substitute for rectum V45Gy, were improved using IGAPT. Also, IGAPT reduced the mean dose to bowel, bladder and rectum significantly (p < 0.01). In addition, an average decrease of rectum V30Gy and bowel V45Gy indicated reductions in toxicity probabilities when using IGAPT. Conclusion This study demonstrates the feasibility of IGAPT in cervical cancer using a plan-library based plan-of-the-day approach. Compared to photon-based IGART, IGAPT maintains target coverage while significant dose reductions for the bladder, bowel and rectum can be achieved.
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Stevenson C, Blaauw R, Fredericks E, Visser J, Roux S. Food avoidance in irritable bowel syndrome leads to a nutrition-deficient diet. SOUTH AFRICAN JOURNAL OF CLINICAL NUTRITION 2016. [DOI: 10.1080/16070658.2014.11734481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Visser J, Notelovitz T, Szabo C, Fredericks N. Abnormal eating attitudes and weight-loss behaviour of adolescent girls attending a “traditional” Jewish high school in Johannesburg, South Africa. SOUTH AFRICAN JOURNAL OF CLINICAL NUTRITION 2016. [DOI: 10.1080/16070658.2014.11734511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Visser J, Marais M, du Plessis J, Steenkamp I, Troskie I. Experiences and attitudes of dietitians during the first compulsory community service year (2003). SOUTH AFRICAN JOURNAL OF CLINICAL NUTRITION 2016. [DOI: 10.1080/16070658.2006.11734084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Visser J, Mackenzie A, Marais D. Job satisfaction of South African registered dietitians. SOUTH AFRICAN JOURNAL OF CLINICAL NUTRITION 2016. [DOI: 10.1080/16070658.2012.11734415] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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92
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De Jong R, Lutkenhaus L, Van Wieringen N, Visser J, Wiersma J, Crama K, Geijsen D, Bel A. SP-0423: Implementation of daily plan selection in rectum. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)31672-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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93
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Crama K, Van de Schoot A, Visser J, Bel A. OC-0081: Robust photon versus robust proton therapy planning with a library of plans for cervical cancer. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)31330-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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94
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Van der Horst A, Houweling A, Visser J, Van Tienhoven G, Bel A. PO-0899: Robustness of fractionated photon RT for pancreatic cancer: Dosimetric effects of anatomical changes. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)32149-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Van Dijk I, Huijskens S, De Jong M, Visser J, Dávila Fajardo R, Rasch C, Alderliesten T, Bel A. OC-0161: Renal and diaphragmatic interfractional motion in children and adults: is there a difference? Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)31410-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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van de Schoot AJAJ, Visser J, van Kesteren Z, Janssen TM, Rasch CRN, Bel A. Beam configuration selection for robust intensity-modulated proton therapy in cervical cancer using Pareto front comparison. Phys Med Biol 2016; 61:1780-94. [PMID: 26854384 DOI: 10.1088/0031-9155/61/4/1780] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The Pareto front reflects the optimal trade-offs between conflicting objectives and can be used to quantify the effect of different beam configurations on plan robustness and dose-volume histogram parameters. Therefore, our aim was to develop and implement a method to automatically approach the Pareto front in robust intensity-modulated proton therapy (IMPT) planning. Additionally, clinically relevant Pareto fronts based on different beam configurations will be derived and compared to enable beam configuration selection in cervical cancer proton therapy. A method to iteratively approach the Pareto front by automatically generating robustly optimized IMPT plans was developed. To verify plan quality, IMPT plans were evaluated on robustness by simulating range and position errors and recalculating the dose. For five retrospectively selected cervical cancer patients, this method was applied for IMPT plans with three different beam configurations using two, three and four beams. 3D Pareto fronts were optimized on target coverage (CTV D(99%)) and OAR doses (rectum V30Gy; bladder V40Gy). Per patient, proportions of non-approved IMPT plans were determined and differences between patient-specific Pareto fronts were quantified in terms of CTV D(99%), rectum V(30Gy) and bladder V(40Gy) to perform beam configuration selection. Per patient and beam configuration, Pareto fronts were successfully sampled based on 200 IMPT plans of which on average 29% were non-approved plans. In all patients, IMPT plans based on the 2-beam set-up were completely dominated by plans with the 3-beam and 4-beam configuration. Compared to the 3-beam set-up, the 4-beam set-up increased the median CTV D(99%) on average by 0.2 Gy and decreased the median rectum V(30Gy) and median bladder V(40Gy) on average by 3.6% and 1.3%, respectively. This study demonstrates a method to automatically derive Pareto fronts in robust IMPT planning. For all patients, the defined four-beam configuration was found optimal in terms of plan robustness, target coverage and OAR sparing.
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Huijskens SC, van Dijk IW, de Jong R, Visser J, Fajardo RD, Ronckers CM, Janssens GO, Maduro JH, Rasch CR, Alderliesten T, Bel A. Quantification of renal and diaphragmatic interfractional motion in pediatric image-guided radiation therapy: A multicenter study. Radiother Oncol 2015; 117:425-31. [DOI: 10.1016/j.radonc.2015.09.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 08/31/2015] [Accepted: 09/17/2015] [Indexed: 10/23/2022]
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Visser J, Cei J, Gutierrez L. The histology of dermal glands of matingBrevicepswith comments on their possible functional value in microhylids (Amphibia: Anura). ACTA ACUST UNITED AC 2015. [DOI: 10.1080/02541858.1982.11447773] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Blaauw R, Daniels L, Du Plessis L, Koen N, Koornhof L, Marais M, Nel D, Van Niekerk E, Visser J. MON-PP256: Missed and Used Opportunities in Health Status Assessment of Children. Clin Nutr 2015. [DOI: 10.1016/s0261-5614(15)30688-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Lutkenhaus LJ, Visser J, de Jong R, Hulshof MC, Bel A. Evaluation of delivered dose for a clinical daily adaptive plan selection strategy for bladder cancer radiotherapy. Radiother Oncol 2015; 116:51-6. [DOI: 10.1016/j.radonc.2015.06.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 06/01/2015] [Accepted: 06/04/2015] [Indexed: 11/25/2022]
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