Radiation treatment dose optimisation using Poisson tumour control probability parameters

G. A. Cho, M. A. Ebert, L. Holloway, Z. Kuncic, C. Baldock, D. I. Thwaites

Research output: Contribution to journalConference paperpeer-review

21 Downloads (Pure)


This study examines the Poisson tumour control probability (TCP) γ₃₇ and D₃₇ parameters of a uniformly irradiated numerical tumour model using changes in tumour burden as a surrogate for treatment response information. An optimum dose Di for a tumour sub-volume element Vi is described that maximizes TCP as a function of fixed tumour integral dose ξ. TCP was calculated for spatially-varying clonogen density for a total 10⁸ cells and radiosensitivity α with mean radiosensitivity in the range 0.4-1.0 Gy⁻¹. A bivariate normal distribution is used to describe the radiosensitivity α and the linear term of the linear-quadratic (LQ) cell kill governed the changes in the regional tumour burden within sub-volumes Vi. The optimum dose distribution, Di, for Vi is obtained as a function of fixed tumour integral dose ξ. For a uniform dose delivery and for TCP = 37%, γ₃₇ and D₃₇ are described by the effective radiosensitivity αeff and the effective clonogen number N0eff, respectively. αeff is equivalent to differential dose changes in the number of clonogenic cells (tumour burden). The γ₃₇ values were found to be inversely correlated with variance of the probability density function of the α distribution. For the biologically optimum dose distribution, γ₃₇ was found to converge to the theoretical maximum limit and D₃₇ was found to reduce relative to that obtained for the uniform dose case. The TCP parameters γ₃₇ and D₃₇ could thus be useful in optimising individual radiation treatment doses even when tumour heterogeneity is taken into account.
Original languageEnglish
Pages (from-to)012047-1-012047-6
Number of pages6
JournalJournal of Physics: Conference Series
Publication statusPublished - 2014
EventInternational Conference on the Use of Computers in Radiation Therapy (17th : 2013) - Melbourne
Duration: 6 May 20139 May 2013

Bibliographical note

Copyright the Author(s). First published in Journal of physics : conference series 489 article 012047. The original publication is available at doi:10.1088/1742-6596/489/1/012047, published by IOP Publishing. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.


Dive into the research topics of 'Radiation treatment dose optimisation using Poisson tumour control probability parameters'. Together they form a unique fingerprint.

Cite this