Real-time dose compensation methods for scanned ion beam therapy of moving tumors.
Technische Universität, Darmstadt
[Ph.D. Thesis], (2012)
Available under Creative Commons Attribution Non-commercial No Derivatives, 2.5.
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|Item Type:||Ph.D. Thesis|
|Title:||Real-time dose compensation methods for scanned ion beam therapy of moving tumors|
Scanned ion beam therapy provides highly tumor-conformal treatments. So far, only tumors showing no considerable motion during therapy have been treated as tumor motion and dynamic beam delivery interfere, causing dose deteriorations. One proposed technique to mitigate these deteriorations is beam tracking (BT), which adapts the beam position to the moving tumor. Despite application of BT, dose deviations can occur in the case of non-translational motion. In this work, real-time dose compensation combined with beam tracking (RDBT) has been implemented into the control system to compensate these dose changes by adaptation of nominal particle numbers during irradiation. Compared to BT, significantly reduced dose deviations were measured using RDBT. Treatment planning studies for lung cancer patients including the increased biological effectiveness of ions revealed a significantly reduced over-dose level (3/5 patients) as well as significantly improved dose homogeneity (4/5 patients) for RDBT. Based on these findings, real-time dose compensated re-scanning (RDRS) has been proposed that potentially supersedes the technically complex fast energy adaptation necessary for BT and RDBT. Significantly improved conformity compared to re-scanning, i.e., averaging of dose deviations by repeated irradiation, was measured in film irradiations. Simulations comparing RDRS to BT revealed reduced under- and overdoses of the former method.
|Place of Publication:||Darmstadt|
|Classification DDC:||500 Naturwissenschaften und Mathematik > 530 Physik|
|Divisions:||05 Department of Physics > Institute for condensed matter physics > Bio Physics|
|Date Deposited:||02 Feb 2012 07:28|
|Last Modified:||07 Dec 2012 12:04|
|Referees:||Durante, Prof. Ph.D Marco and Gerhard, Prof. Dr. Kraft|
|Refereed:||12 December 2011|