James Bedford
Team Leader
Radiotherapy Treatment Planning
The Institute Of Cancer Research
United Kingdom
Biography
The work of the Radiotherapy Treatment Planning team relates to inverse planning and treatment delivery for intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). The AutoBeam in-house treatment planning system is being used to incorporate the latest advances in inverse planning, including beam orientation optimisation for conformal radiotherapy. For IMRT, the team is working on direct-aperture optimisation, providing effective treatment plans with the simplest and dosimetrically most accurate delivery. This work also includes beam orientation optimisation for IMRT, which is one of the most computationally challenging problems in radiotherapy. The team is also involved in the development and clinical implementation of VMAT for a variety of clinical sites, including lung, brain and prostate. Research activities have broadened into in vivo portal dosimetry. Methods have been developed for predicting portal images produced by VMAT treatments. The actual measured image at the time of treatment can then be compared with this predicted image, thereby providing a measure of the accuracy of delivered dose. This method of portal imaging is now in routine clinical use.
Research Interest
Other current interests of the team include 4D and adaptive radiotherapy. The team is contributing to studies demonstrating the use of multileaf collimator tracking for moving lung tumours, and has carried out a study investigating the impact of tracking latency on this type of treatment. There is interest in inter-fraction adaptive radiotherapy with VMAT, including the image registration and dose warping that relate to this. Accuracy of dose calculation is important, so this remains part of the work of the team.
Publications
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Bedford, J.L., Chajecka-Szczygielska, H. & Thomas, M.D. (2015). Quality control of VMAT synchronization using portal imaging. Journal of applied clinical medical physics, Vol.16(1), p. 5238.
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Bedford, J.L., Chajecka-Szczygielska, H. & Thomas, M.D. (2015). Quality control of VMAT synchronization using portal imaging. Journal of applied clinical medical physics, Vol.16(1), pp. 284-297
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Fast, M.F., Kamerling, C.P., Ziegenhein, P., Menten, M.J., Bedford, J.L., Nill, S. & Oelfke, U. (2016). Assessment of MLC tracking performance during hypofractionated prostate radiotherapy using real-time dose reconstruction. Physics in medicine and biology, Vol.61(4), pp. 1546-1562.
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Smyth, G., Evans, P.M., Bamber, J.C., Mandeville, H.C., Welsh, L.C., Saran, F.H. & Bedford, J.L. (2016). Non-coplanar trajectories to improve organ at risk sparing in volumetric modulated arc therapy for primary brain tumors. Radiotherapy and oncology, Vol.121(1), pp. 124-131.
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Bedford, J.L., Smyth, G., Hanson, I.M., Tree, A.C., Dearnaley, D.P. & Hansen, V.N. (2016). Quality of treatment plans and accuracy of in vivo portal dosimetry in hybrid intensity-modulated radiation therapy and volumetric modulated arc therapy for prostate cancer. Radiotherapy and oncology, Vol.120(2), pp. 320-326.
