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Fekete Viktˇria (2017)

Weitere Beteiligte (Hrsg. etc.):
Comparison of different imaging strategies in IGRT for the thoracic region regarding dose, workflow and image quality
FH Wr. Neustadt;

Link zum Volltext:

Kurzfassung in Deutsch

Image-guided radiation therapy (IGRT) is one of the most sophisticated application of modern radiation oncology. During an IGRT procedure, an online image is taken of the patient, lying on the treatment couch. After registration of the online and topometric images, the patient is moved with the couch to the treatment position. Using IGRT it is possible to increase the precision and accuracy of radiotherapy, and therefore to reduce safety margins during treatment planning. Different imaging procedures are available on Varian TrueBeam machine; these are planar images with kilovoltage (kV) or megavoltage (MV) energies and kilovoltage Cone-Beam Computed Tomography (kV-CBCT). In the case of MV planar imaging we measured 6 MV energy with 1.5 and 3 Monitor Units. In the case of planar kV imaging we used with 3 different kV values and 4 different mAs values. In case of kV-CBCT we used the same 3 kV parameters as for planar kV images, but we set only 270 mAs.There are many opportunities to measure the dose which come from IGRT. In our study, we used thermoluminescent dosimeters (TLDs), the RTI Barracuda system and CTDI phantom. The image quality is also an important factor, which was evaluated by the IBA Primus L phantom and Catphan 504 phantom. We measured the necessary time for all the three modalities. We collected the dose results, the line pair resolution, the low and high contrast resolution and the summary of points which originate from the human observers' ratings. The lowest dose was measured in the planar kV imaging. The following is the kV- CBCT. The highest dose can be attributed to the MV imaging.140 kV with 10 mAs had the worst low and high contrast resolution, because the saturation of the detector. In some case the low and the high contrast test items are getting undetectable, because too much photon are incident to the detector.In planar MV imaging and kV-CBCT imaging, the machine's default setting is acceptable to be used in the daily routine. In kV images, it is possible to reduce mAs, because it reduces the dose of the phantom surface while the image quality remains acceptable.

Kurzfassung in Englisch

Image-guided radiation therapy (IGRT) is one of the most sophisticated application of modern radiation oncology. During an IGRT procedure, an online image is taken of the patient, lying on the treatment couch. After registration of the online and topometric images, the patient is moved with the couch to the treatment position. Using IGRT it is possible to increase the precision and accuracy of radiotherapy, and therefore to reduce safety margins during treatment planning. Different imaging procedures are available on Varian TrueBeam machine; these are planar images with kilovoltage (kV) or megavoltage (MV) energies and kilovoltage Cone-Beam Computed Tomography (kV-CBCT). In the case of MV planar imaging we measured 6 MV energy with 1.5 and 3 Monitor Units. In the case of planar kV imaging we used with 3 different kV values and 4 different mAs values. In case of kV-CBCT we used the same 3 kV parameters as for planar kV images, but we set only 270 mAs.There are many opportunities to measure the dose which come from IGRT. In our study, we used thermoluminescent dosimeters (TLDs), the RTI Barracuda system and CTDI phantom. The image quality is also an important factor, which was evaluated by the IBA Primus L phantom and Catphan 504 phantom. We measured the necessary time for all the three modalities. We collected the dose results, the line pair resolution, the low and high contrast resolution and the summary of points which originate from the human observers' ratings. The lowest dose was measured in the planar kV imaging. The following is the kV- CBCT. The highest dose can be attributed to the MV imaging.140 kV with 10 mAs had the worst low and high contrast resolution, because the saturation of the detector. In some case the low and the high contrast test items are getting undetectable, because too much photon are incident to the detector.In planar MV imaging and kV-CBCT imaging, the machine's default setting is acceptable to be used in the daily routine. In kV images, it is possible to reduce mAs, because it reduces the dose of the phantom surface while the image quality remains acceptable.

Allgemeine Angaben

Hochschule: FH Wr. Neustadt
Studiengang:
SWD-Schlagw÷rter:
Freie Schlagw÷rter: Image-Guided Radiation Therapy,Imaging dose,MV and kV imaging,Radiotherapy of chest,Image Quality,Workflow,Image-Guided Radiation Therapy,Imaging dose,MV and kV imaging,Radiotherapy of chest,Image Quality,Workflow
Freie Schlagw÷rter (Englisch):
DDC-Sachgruppe:
Sonstige beteiligte Institution:
Dokumentart: Diplomarbeit, Masterthesis etc.
ISBN:
Quelle:
Sprache:
Umfang: 1
1. Gutachter: DI Dr. Winkler Peter MAS
2. Gutachter:
Verbund-ID-Nr.:
Begleitmaterial
Ang. z. Inhalt
Bibliotheks-Nr.
Einreichdatum: 3. 2017
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