Abstract
Lung cancer is one of the most common cancers world-wide and the leading cause of
cancer deaths. In locally advanced lung cancer, the recommended treatment is radiotherapy
in combination with chemotherapy. Lung cancer radiotherapy is a complex issue due to
substantial uncertainties in treatment delivery, e.g. breathing related tumour motion and
anatomical changes during treatment. To ensure dose delivery to the target, a safety margin
is added to the tumour. A large treatment volume, however, can be problematic due to the
proximity of vital anatomical structures in the chest region, e.g. the heart and the lungs.
Breathing adaptation and fiducial markers are tools which can increase precision in lung
cancer radiotherapy.
The primary aim of this thesis was to evaluate a novel liquid fiducial marker in both a
pre-clinical and a clinical setting. The marker was tested rigorously for visibility, possible
dose perturbation and volumetric changes. We found that the liquid fiducial marker was an
excellent alternative to solid fiducial markers. It showed small dose perturbations in proton
therapy, was volumetrically stable during several weeks of radiotherapy and functioned well
as a surrogate for the tumour position in lung cancer patients.
Furthermore, we evaluated the potential benefit of a breathing adaptation technique,
where patients hold their breath during treatment delivery. We found that this technique
reduced both tumour motion and doses to risk organs.
Finally, we investigated the potential of measuring radiation doses from an activated liquid
silver marker, via photon-nuclear reactions in-situ, using positron emission-tomography
and proved a clear correlation between delivered radiation dose and measured induced activity.
cancer deaths. In locally advanced lung cancer, the recommended treatment is radiotherapy
in combination with chemotherapy. Lung cancer radiotherapy is a complex issue due to
substantial uncertainties in treatment delivery, e.g. breathing related tumour motion and
anatomical changes during treatment. To ensure dose delivery to the target, a safety margin
is added to the tumour. A large treatment volume, however, can be problematic due to the
proximity of vital anatomical structures in the chest region, e.g. the heart and the lungs.
Breathing adaptation and fiducial markers are tools which can increase precision in lung
cancer radiotherapy.
The primary aim of this thesis was to evaluate a novel liquid fiducial marker in both a
pre-clinical and a clinical setting. The marker was tested rigorously for visibility, possible
dose perturbation and volumetric changes. We found that the liquid fiducial marker was an
excellent alternative to solid fiducial markers. It showed small dose perturbations in proton
therapy, was volumetrically stable during several weeks of radiotherapy and functioned well
as a surrogate for the tumour position in lung cancer patients.
Furthermore, we evaluated the potential benefit of a breathing adaptation technique,
where patients hold their breath during treatment delivery. We found that this technique
reduced both tumour motion and doses to risk organs.
Finally, we investigated the potential of measuring radiation doses from an activated liquid
silver marker, via photon-nuclear reactions in-situ, using positron emission-tomography
and proved a clear correlation between delivered radiation dose and measured induced activity.
| Original language | English |
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| Publisher | The Niels Bohr Institute, Faculty of Science, University of Copenhagen |
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| Number of pages | 182 |
| Publication status | Published - 2016 |
