- Title
- Two non-parametric methods for derivation of constraints from radiotherapy dose-histogram data
- Creator
- Ebert, M. A.; Gulliford, S. L.; Buettner, F.; Foo, K.; Haworth, A.; Kennedy, A.; Joseph, D. J.; Denham, J. W.
- Relation
- NHMRC.1006447
- Relation
- Physics in Medicine and Biology Vol. 59, Issue 13, p. N101-N111
- Publisher Link
- http://dx.doi.org/10.1088/0031-9155/59/13/N101
- Publisher
- Institute of Physics
- Resource Type
- journal article
- Date
- 2014
- Description
- Dose constraints based on histograms provide a convenient and widely-used method for informing and guiding radiotherapy treatment planning. Methods of derivation of such constraints are often poorly described. Two non-parametric methods for derivation of constraints are described and investigated in the context of determination of dose-specific cut-points—values of the free parameter (e.g., percentage volume of the irradiated organ) which best reflect resulting changes in complication incidence. A method based on receiver operating characteristic (ROC) analysis and one based on a maximally-selected standardized rank sum are described and compared using rectal toxicity data from a prostate radiotherapy trial. Multiple test corrections are applied using a free step-down resampling algorithm, which accounts for the large number of tests undertaken to search for optimal cut-points and the inherent correlation between dose–histogram points. Both methods provide consistent significant cut-point values, with the rank sum method displaying some sensitivity to the underlying data. The ROC method is simple to implement and can utilize a complication atlas, though an advantage of the rank sum method is the ability to incorporate all complication grades without the need for grade dichotomization.
- Subject
- radiotherapy; dose volume histograms; treatment complications; toxicity; constraints
- Identifier
- http://hdl.handle.net/1959.13/1304107
- Identifier
- uon:20796
- Identifier
- ISSN:0031-9155
- Language
- eng
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