Search

Your search keyword '"Woodings, S J"' showing total 17 results
Start Over Author "Woodings, S J"
17 results on '"Woodings, S J"'

2. Dosimetric evaluation of off-axis fields and angular transmission for the 1.5 T MR-linac

Author

Radiotherapie, Experimentele klinische fysica, Cancer, Klinische Fysica RT, UMC Utrecht Holding, van den Dobbelsteen, M., Hackett, S. L., de Vries, J. H.W., van Asselen, B., Oolbekkink, S., Woodings, S. J., Raaymakers, B. W., Radiotherapie, Experimentele klinische fysica, Cancer, Klinische Fysica RT, UMC Utrecht Holding, van den Dobbelsteen, M., Hackett, S. L., de Vries, J. H.W., van Asselen, B., Oolbekkink, S., Woodings, S. J., and Raaymakers, B. W.

Published
2022

4. Technical Note: Consistency of PTW30013 and FC65-G ion chamber magnetic field correction factors

Author

ICT RT, Fysica Radiotherapie Research, Cancer, Klinische Fysica RT, Experimentele klinische fysica, Woodings, S. J., van Asselen, B., van Soest, T. L., de Prez, L. A., Lagendijk, J. J.W., Raaymakers, B. W., Wolthaus, J. W.H., ICT RT, Fysica Radiotherapie Research, Cancer, Klinische Fysica RT, Experimentele klinische fysica, Woodings, S. J., van Asselen, B., van Soest, T. L., de Prez, L. A., Lagendijk, J. J.W., Raaymakers, B. W., and Wolthaus, J. W.H.

Published
2019

5. 'First in man' treatments with the MRI-linac provide clinical proof of the concept

Author

Jurgenliemk-Schulz, I. M., Raaymakers, B. W., Van Asselen, B., Bol, G. H., Brown, K. J., Doornaert, P., De Groot-van Breugel, E. N., Hackett, S. L., Kasperts, N., Kiekebosch, I. H., Kerkmeijer, L. G. W., Kok, J. G. M., Kotte, A. N. T., Meijers, L. T. C., Nomden, C. N., Pais, B. R., Philippens, M. E. P., Sikkes, G. G., Tersteeg, J. H. A., Tijssen, R. H. N., Wolthaus, J. W. H., Woodings, S. J., and Lagendijk, J. J. W.

Published
2018

7. 'First in man' treatments with the MRI-linac provide clinical proof of the concept

Author

MS Radiotherapie, Cancer, Experimentele klinische fysica, Klinische Fysica RT, Fysica Radiotherapie Research, Jurgenliemk-Schulz, I. M., Raaymakers, B. W., Van Asselen, B., Bol, G. H., Brown, K. J., Doornaert, P., De Groot-van Breugel, E. N., Hackett, S. L., Kasperts, N., Kiekebosch, I. H., Kerkmeijer, L. G. W., Kok, J. G. M., Kotte, A. N. T., Meijers, L. T. C., Nomden, C. N., Pais, B. R., Philippens, M. E. P., Sikkes, G. G., Tersteeg, J. H. A., Tijssen, R. H. N., Wolthaus, J. W. H., Woodings, S. J., Lagendijk, J. J. W., MS Radiotherapie, Cancer, Experimentele klinische fysica, Klinische Fysica RT, Fysica Radiotherapie Research, Jurgenliemk-Schulz, I. M., Raaymakers, B. W., Van Asselen, B., Bol, G. H., Brown, K. J., Doornaert, P., De Groot-van Breugel, E. N., Hackett, S. L., Kasperts, N., Kiekebosch, I. H., Kerkmeijer, L. G. W., Kok, J. G. M., Kotte, A. N. T., Meijers, L. T. C., Nomden, C. N., Pais, B. R., Philippens, M. E. P., Sikkes, G. G., Tersteeg, J. H. A., Tijssen, R. H. N., Wolthaus, J. W. H., Woodings, S. J., and Lagendijk, J. J. W.

Published
2018

9. Beam characterisation of the 1.5 T MRI-linac

Author

Woodings, S J, primary, Bluemink, J J, additional, de Vries, J H W, additional, Niatsetski, Y, additional, van Veelen, B, additional, Schillings, J, additional, Kok, J G M, additional, Wolthaus, J W H, additional, Hackett, S L, additional, van Asselen, B, additional, van Zijp, H M, additional, Pencea, S, additional, Roberts, D A, additional, Lagendijk, J J W, additional, and Raaymakers, B W, additional

Published
2018
Full Text
View/download PDF

12. First patients treated with a 1.5 T MRI-Linac: clinical proof of concept of a high-precision, high-field MRI guided radiotherapy treatment

Author

Raaymakers, B W, primary, Jürgenliemk-Schulz, I M, additional, Bol, G H, additional, Glitzner, M, additional, Kotte, A N T J, additional, van Asselen, B, additional, de Boer, J C J, additional, Bluemink, J J, additional, Hackett, S L, additional, Moerland, M A, additional, Woodings, S J, additional, Wolthaus, J W H, additional, van Zijp, H M, additional, Philippens, M E P, additional, Tijssen, R, additional, Kok, J G M, additional, de Groot-van Breugel, E N, additional, Kiekebosch, I, additional, Meijers, L T C, additional, Nomden, C N, additional, Sikkes, G G, additional, Doornaert, P A H, additional, Eppinga, W S C, additional, Kasperts, N, additional, Kerkmeijer, L G W, additional, Tersteeg, J H A, additional, Brown, K J, additional, Pais, B, additional, Woodhead, P, additional, and Lagendijk, J J W, additional

Published
2017
Full Text
View/download PDF

13. First patients treated with a 1.5 T MRI-Linac : Clinical proof of concept of a high-precision, high-field MRI guided radiotherapy treatment

Author

Raaymakers, B W, Jürgenliemk-Schulz, I M, Bol, G H, Glitzner, M, Kotte, A N T J, van Asselen, B, de Boer, J C J, Bluemink, J J, Hackett, S L, Moerland, M A, Woodings, S J, Wolthaus, J W H, van Zijp, H M, Philippens, M E P, Tijssen, R, Kok, J G M, de Groot-van Breugel, E N, Kiekebosch, I, Meijers, L T C, Nomden, C.N., Sikkes, Gonda G, Doornaert, P A H, Eppinga, W S C, Kasperts, N, Kerkmeijer, L G W, Tersteeg, J H A, Brown, Kristy J., Pais, B, Woodhead, P, Lagendijk, J J W, Raaymakers, B W, Jürgenliemk-Schulz, I M, Bol, G H, Glitzner, M, Kotte, A N T J, van Asselen, B, de Boer, J C J, Bluemink, J J, Hackett, S L, Moerland, M A, Woodings, S J, Wolthaus, J W H, van Zijp, H M, Philippens, M E P, Tijssen, R, Kok, J G M, de Groot-van Breugel, E N, Kiekebosch, I, Meijers, L T C, Nomden, C.N., Sikkes, Gonda G, Doornaert, P A H, Eppinga, W S C, Kasperts, N, Kerkmeijer, L G W, Tersteeg, J H A, Brown, Kristy J., Pais, B, Woodhead, P, and Lagendijk, J J W

Published
2017

14. First patients treated with a 1.5 T MRI-Linac: Clinical proof of concept of a high-precision, high-field MRI guided radiotherapy treatment

Author

Experimentele klinische fysica, Cancer, MS Radiotherapie, Klinische Fysica RT, Fysica Radiotherapie Research, Raaymakers, B W, Jürgenliemk-Schulz, I M, Bol, G H, Glitzner, M, Kotte, A N T J, van Asselen, B, de Boer, J C J, Bluemink, J J, Hackett, S L, Moerland, M A, Woodings, S J, Wolthaus, J W H, van Zijp, H M, Philippens, M E P, Tijssen, R, Kok, J G M, de Groot-van Breugel, E N, Kiekebosch, I, Meijers, L T C, Nomden, C.N., Sikkes, Gonda G, Doornaert, P A H, Eppinga, W S C, Kasperts, N, Kerkmeijer, L G W, Tersteeg, J H A, Brown, Kristy J., Pais, B, Woodhead, P, Lagendijk, J J W, Experimentele klinische fysica, Cancer, MS Radiotherapie, Klinische Fysica RT, Fysica Radiotherapie Research, Raaymakers, B W, Jürgenliemk-Schulz, I M, Bol, G H, Glitzner, M, Kotte, A N T J, van Asselen, B, de Boer, J C J, Bluemink, J J, Hackett, S L, Moerland, M A, Woodings, S J, Wolthaus, J W H, van Zijp, H M, Philippens, M E P, Tijssen, R, Kok, J G M, de Groot-van Breugel, E N, Kiekebosch, I, Meijers, L T C, Nomden, C.N., Sikkes, Gonda G, Doornaert, P A H, Eppinga, W S C, Kasperts, N, Kerkmeijer, L G W, Tersteeg, J H A, Brown, Kristy J., Pais, B, Woodhead, P, and Lagendijk, J J W

Published
2017

15. Consequences of air around an ionization chamber : Are existing solid phantoms suitable for reference dosimetry on an MR-linac?

Author

Hackett, S. L., Van Asselen, B., Wolthaus, J. W H, Kok, J. G M, Woodings, S. J., Lagendijk, J. J W, and Raaymakers, B. W.

Subjects
dosimetry, ionization chamber, Radiology Nuclear Medicine and imaging, Biophysics, Journal Article, plastic phantom, equipment and supplies, MR-linac
Abstract

Purpose: A protocol for reference dosimetry for the MR-linac is under development. The 1.5 T magnetic field changes the mean path length of electrons in an air-filled ionization chamber but has little effect on the electron trajectories in a surrounding phantom. It is therefore necessary to correct the response of an ionization chamber for the influence of the magnetic field. Solid phantoms are used for dosimetry measurements on the MR-linac, but air is present between the chamber wall and phantom insert. This study aimed to determine if this air influences the ion chamber measurements on the MR-linac. The absolute response of the chamber and reproducibility of dosimetry measurements were assessed on an MR-linac in solid and water phantoms. The sensitivity of the chamber response to the distribution of air around the chamber was also investigated. Methods: Measurements were performed on an MR-linac and replicated on a conventional linac for five chambers. The response of three waterproof chambers was measured with air and with water between the chamber and the insert to measure the influence of the air volume on absolute chamber response. The distribution of air around the chamber was varied indirectly by rotating each chamber about the longitudinal chamber axis in a solid phantom and a water phantom (waterproof chambers only) and measuring the angular dependence of the chamber response, and varied directly by displacing the chamber in the phantom insert using a paper shim positioned at different orientations between the chamber casing and the insert. Results: The responses of the three waterproof chambers measured on the MR-linac were 0.7%-1.2% higher with water than air in the chamber insert. The responses of the chambers on the conventional linac changed by less than 0.3% when air in the insert was replaced with water. The angular dependence of the chambers ranged from 0.6% to 1.9% in the solid phantom on the MR-linac but was less than 0.5% in water on the MR-linac and less than 0.3% in the solid phantom on the conventional linac. Inserting a shim around the chamber induced changes of the chamber response in a magnetic field of up to 2.2%, but the change in chamber response on the conventional linac was less than 0.3%. Conclusions: The interaction between the magnetic field and secondary electrons in the air around the chamber reduces the charge collected from 0.7% to 1.2%. The large angular dependence of ion chambers measured in the plastic phantom in a magnetic field appears to arise from a change of air distribution as the chamber is moved within the insert, rather than an intrinsic isotropy of the chamber sensitivity to radiation. It is recommended that reference dosimetry measurements on the MR-linac can be performed only in water, rather than in existing plastic phantoms.

Published
2016

16. Consequences of air around an ionization chamber: Are existing solid phantoms suitable for reference dosimetry on an MR-linac?

Author

Radiotherapie, Fysica Radiotherapie Research, Cancer, Experimentele klinische fysica, Hackett, S. L., Van Asselen, B., Wolthaus, J. W H, Kok, J. G M, Woodings, S. J., Lagendijk, J. J W, Raaymakers, B. W., Radiotherapie, Fysica Radiotherapie Research, Cancer, Experimentele klinische fysica, Hackett, S. L., Van Asselen, B., Wolthaus, J. W H, Kok, J. G M, Woodings, S. J., Lagendijk, J. J W, and Raaymakers, B. W.

Published
2016

17. Consequences of air around an ionization chamber: Are existing solid phantoms suitable for reference dosimetry on an MR-linac?

Author

Hackett SL, van Asselen B, Wolthaus JW, Kok JG, Woodings SJ, Lagendijk JJ, and Raaymakers BW

Subjects
Equipment Design, Magnetic Resonance Imaging methods, Radiotherapy, Image-Guided instrumentation, Radiotherapy, Image-Guided methods, Water, Air, Magnetic Resonance Imaging instrumentation, Particle Accelerators instrumentation, Phantoms, Imaging, Radiometry instrumentation, Radiometry methods
Abstract

Purpose: A protocol for reference dosimetry for the MR-linac is under development. The 1.5 T magnetic field changes the mean path length of electrons in an air-filled ionization chamber but has little effect on the electron trajectories in a surrounding phantom. It is therefore necessary to correct the response of an ionization chamber for the influence of the magnetic field. Solid phantoms are used for dosimetry measurements on the MR-linac, but air is present between the chamber wall and phantom insert. This study aimed to determine if this air influences the ion chamber measurements on the MR-linac. The absolute response of the chamber and reproducibility of dosimetry measurements were assessed on an MR-linac in solid and water phantoms. The sensitivity of the chamber response to the distribution of air around the chamber was also investigated., Methods: Measurements were performed on an MR-linac and replicated on a conventional linac for five chambers. The response of three waterproof chambers was measured with air and with water between the chamber and the insert to measure the influence of the air volume on absolute chamber response. The distribution of air around the chamber was varied indirectly by rotating each chamber about the longitudinal chamber axis in a solid phantom and a water phantom (waterproof chambers only) and measuring the angular dependence of the chamber response, and varied directly by displacing the chamber in the phantom insert using a paper shim positioned at different orientations between the chamber casing and the insert., Results: The responses of the three waterproof chambers measured on the MR-linac were 0.7%-1.2% higher with water than air in the chamber insert. The responses of the chambers on the conventional linac changed by less than 0.3% when air in the insert was replaced with water. The angular dependence of the chambers ranged from 0.6% to 1.9% in the solid phantom on the MR-linac but was less than 0.5% in water on the MR-linac and less than 0.3% in the solid phantom on the conventional linac. Inserting a shim around the chamber induced changes of the chamber response in a magnetic field of up to 2.2%, but the change in chamber response on the conventional linac was less than 0.3%., Conclusions: The interaction between the magnetic field and secondary electrons in the air around the chamber reduces the charge collected from 0.7% to 1.2%. The large angular dependence of ion chambers measured in the plastic phantom in a magnetic field appears to arise from a change of air distribution as the chamber is moved within the insert, rather than an intrinsic isotropy of the chamber sensitivity to radiation. It is recommended that reference dosimetry measurements on the MR-linac can be performed only in water, rather than in existing plastic phantoms.

Published
2016
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results