Tumor targeting in external beam radiotherapy is a crucial issue, as the accuracy that can be achieved is directly related to local tumor control and side effects. This applies both to conventional radiation therapy, that uses photons and electrons, and to particle therapy, where protons and ions provide higher geometrical selectivity and enhanced biological effects. Current strategies prescribe the massive use of image guidance technologies to maximize the targeting accuracy (Image Guided RadioTherapy, IGRT).When IGRT is applied to moving tumors, such as in the lung or liver, image guidance becomes challenging, as motion leads to increased uncertainty. Furthermore, the need of continuously monitoring tumor motion to achieve adequate tumor targeting accuracy limits the applicability of IGRT technologies due to imaging dose constraints. Therefore, minimally invasive technologies for continuous monitoring, such as optical tracking and surface detection, have been proposed for real-time tumor targeting.In this chapter we focus on real-time tumor targeting of moving tumors, investigating the applicability of using external surrogates combined with periodic imaging to model tumor motion. We first present the theoretical background of computing targeting errors with moving targets. Then we review the state of the art technologies and quantify the actual targeting accuracy based on published data and retrospective clinical studies. Finally we compare different strategies to model tumor motion in a patient database, discussing the use of different correlation models, the need of model updating, and the best trade off between targeting accuracy and imaging dose.
|Title of host publication||Brain Cancer, Tumor Targeting and Cervical Cancer|
|Publisher||Nova Science Publishers, Inc.|
|Number of pages||14|
|Publication status||Published - Jan 2011|
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)