Planung und Kontrolle von Operationen und Interventionen anhand der Computertomographie

Die Behandlung eines Bronchialkarzinoms (Lungenkrebs) erfolgt häufig durch einen chirurgischen Eingriff. Dabei wird immer mehr dazu übergegangen, durch anspruchsvolle Operationstechniken, so genannte Manschetten- oder Keilresektionen, möglichst viel gesundes Lungengewebe zu erhalten, anstatt komplette Lungenlappen oder sogar einen ganzen Lungenflügel zu entfernen. Die dadurch entstandenen Verbindungsstellen (Anastomosen) bedürfen einer besonderen Planung sowie einer postoperativen Kontrolle. Diese Arbeit präsentiert eine semiautomatische Analyse von Bronchialsegmenten, dabei wird der Durchmesserund Lumenverlauf des betrachteten Segmentes orthogonal zur Bronchus-Achse berechnet. Diese Berechnungen werden auf dem originalen Grauwertvolumen basierend auf einer Kombination der ersten und zweiten Ableitung berechnet. Zusätzlich werden zur Bronchus-Achse parallele Längs- und Querschnitte erzeugt, um durch den Verlauf des Gefäßes zu navigieren und diesen so besser beurteilen zu können. Medical treatment of bronchial carcinoma (non small lung cancer) often includes a surgical intervention. New challenging bronchial reconstruction techniques (wedge resection, end-to-end-anastomosis, y-sleeve) allow the derivation of healthy lung tissue, but require a special planning and postoperative supervision. This work presents a semi-automatic analysis of bronchial segments by calculation the run of cross section diameter and lumen. These measurements are conducted in the original gray-level volume by a combination of the first and second derivatives. Furthermore there is a bronchial-axis parallel and perpendicular visualisation to navigate through the bronchial segment and get a better spacial impression

Optimization of Carbon Ion Treatment Plans by Integrating Tissue Specific α/β-Values for Patients with Non-Resectable Pancreatic Cancer.

The aim of the thesis is to improve treatment plans of carbon ion irradiation by integrating the tissues' specific [Formula: see text]-values for patients with locally advanced pancreatic cancer (LAPC).Five patients with LAPC were included in this study. By the use of the treatment planning system Syngo RT Planning (Siemens, Erlangen, Germany) treatment plans with carbon ion beams have been created. Dose calculation was based on [Formula: see text]-values for both organs at risk (OAR) and the tumor. Twenty-five treatment plans and thirty-five forward calculations were created. With reference to the anatomy five field configurations were included. Single Beam Optimization (SBO) and Intensity Modulated Particle Therapy (IMPT) were used for optimization. The plans were analyzed with respect to both dose distributions and individual anatomy. The plans were evaluated using a customized index.With regard to the target, a field setup with one single posterior field achieves the highest score in our index. Field setups made up of three fields achieve good results in OAR sparing. Nevertheless, the field setup with one field is superior in complex topographic conditions. But, allocating an [Formula: see text]-value of 2 Gy to the spinal cord leads to critical high maximum doses in the spinal cord. The evaluation of dose profiles showed significant dose peaks at borders of the [Formula: see text]-gradient, especially in case of a single posterior field.Optimization with specific [Formula: see text]-values allows a more accurate view on dose distribution than previously. A field setup with one single posterior field achieves good results in case of difficult topographic conditions, but leads to high maximum doses to the spinal cord. So, field setups with multiple fields seem to be more adequate in case of LAPC, being surrounded by highly radiosensitive normal tissues

Optimization Process: Case 5, FS 5.

<p>Optimization process consisting of up to 3 steps: target plan optimization and 2 forward calculations.</p

Dose profile in the beam channel: Case 4, FS 4, 270°.

<p>Demonstration of the dose profile from the proximal to the distal part of the beam channel.</p

FS Evaluation: Dose profile.

<p>FS Evaluation: Dose profile.</p

Index Evaluation.

<p>Comparison of the plans by the three indices. Target Criteria, OAR Criteria, and Cumulative Criteria.</p

ratios, Target, OAR and Cumulative criteria.

<p> ratios, Target, OAR and Cumulative criteria.</p

Optimization Process: Case 5, FS 5.

<p>Optimization process consisting of up to 3 steps: target plan optimization and 2 forward calculations.</p

Field Setups: Characteristics.

<p>Description of 5 field setups with their dose distribution in case 5.</p

Dose profile in the beam channel: Case 4, FS 4, 270°.

<p>Demonstration of the dose profile from the proximal to the distal part of the beam channel.</p