[Spiral computed tomography for treatment planning and quality assurance in radiotherapy].
BACKGROUND
The possibilities of spiral CT for radiotherapeutic treatment planning and quality assurance have been systematically investigated.


METHODS
The influence of parameters such as slice thickness, table speed and increment on geometric accuracy was studied. Ring-, spheric-, PMMA- and humanoid Alderson phantoms were used. Furthermore, patients with infradiaphragmatic irradiation of Hodgkin's disease or with mediastinal irradiation were studied using CT-angiography. Patients with carcinomas of the head and neck before HDR- and PDR-brachytherapy were examined as well.


RESULTS
Spiral CT offers 3D volume data information with excellent reduction of breath and motion artefacts for virtual simulation. 2D multiplanar reconstructions with excellent local resolution may be obtained. 3D MIP (Maximum Intensity Projection), based on CT-angiographic imaging, is a good tool for infradiaphragmatic treatment planning of Hodgkin's disease, if small numbers for slice thickness, table speed and increment are used. SSD (Surface Shaded Display) offers good 3D visualization and good geometric control of intracavitary and interstitial brachytherapy applicators. High qualitative multiplanar reconstructions are useful for CT-based brachytherapy planning.


CONCLUSIONS
Spiral CT is a precious tool for 3D treatment planning and virtual simulation in radiotherapy and superior to conventional CT data acquisition. Quality assurance is improved for dose-volume-histograms and for brachytherapy.
Zimmermann
J S
JS
Klinik für Strahlentherapie, Christian-Albrechts-Universität Kiel.
Blume
J
J
Zimmermann
P
P
Kovács
G
G
Jensen
M
M
Hutzelmann
A
A
Freund
M
M
Kimmig
B
B
D000792:Angiography / Q000295:instrumentation / Q000379:methods / Q000706:statistics & numerical data; D001918:Brachytherapy / Q000592:standards* / Q000706:statistics & numerical data; D003287:Contrast Media / Q000008:administration & dosage; D006258:Head and Neck Neoplasms / Q000532:radiotherapy; D006689:Hodgkin Disease / Q000532:radiotherapy; D006801:Humans; D019047:Phantoms, Imaging; D011785:Quality Assurance, Health Care / Q000706:statistics & numerical data; D011867:Radioisotope Teletherapy / Q000592:standards* / Q000706:statistics & numerical data; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods* / Q000706:statistics & numerical data; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data
D003287:Contrast Media