TY  - GEN
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/4673/
KW  - relative biologische Wirksamkeit 
KW  -  linearer Energietransfer 
KW  -  inverse Bestrahlungsplanungrelative biological effectiveness 
KW  -  linear energy transfer 
KW  -  proton therapy 
KW  -  optimization 
KW  -  inverse planning
N1  - Parts of this work are published in "Medical Physics" (vol 30, pp 806-815, copyright 2003 American Association of Physicists in Medicine), "Zeitschrift f. Medizinische Physik" (vol 14, pp 41-46, 2004) and "Physics in Medicine and Biology" (vol 49, in press, copyright 2004 IOP Publishing Ltd.) 
Y1  - 2004///
A1  - Wilkens, Jan Jakob
AV  - public
ID  - heidok4673
TI  - Evaluation of Radiobiological Effects in Intensity Modulated Proton Therapy : New Strategies for Inverse Treatment Planning
N2  - Currently, treatment planning for intensity modulated proton therapy (IMPT) usually disregards variations of the relative biological effectiveness (RBE). To investigate the potential clinical relevance of a variable RBE for beam scanning techniques, new strategies for the evaluation of radiobiological effects and for the incorporation of the RBE into the inverse planning process are presented. These strategies are based on a fast algorithm for three-dimensional calculations of the dose averaged linear energy transfer (LET) as a measure of the local radiation quality, and on a simple phenomenological approach for the RBE as a function of dose, LET and tissue type. It was found that the biological effect depended strongly on the type of scanning technique used, mainly due to differences in the LET distributions. New objective functions that account for LET and RBE were integrated into an inverse planning software, which now allows simultaneous multi-field optimization of the biological effect in a reasonable time. With these methods, unfavourable RBE effects can be identified and compensated for by direct optimization of the product of RBE and dose, which is demonstrated for several clinical examples. The proposed strategies are therefore valuable tools to evaluate and improve the quality of treatment plans in IMPT.
ER  -