Estimation and analysis of uncertainties in patient position during 3D Conformal Radiation Therapy

• Κύριος συγγραφέας: Μυλωνά, Βασιλική
• Άλλοι συγγραφείς: Ευσταθόπουλος, Ευστάθιος
• Μορφή: Thesis
• Γλώσσα: English
• Έκδοση: 2019
• Θέματα: Radiotherapy; ‘’Attikon’’ General University Hospital; Van Herk formula; Ραδιοθεραπεία; Γενικό Νοσοκομείο "Αττικόν"; 615.842

This thesis introduces the concept of patient Set-up uncertainties, underlines their significance in a Radiotherapy Department and presents an evaluation of the magnitude of such uncertainties in the Radiotherapy Department of the ‘’Attikon’’ General University Hospital of Athens. In this research 90 patients were examined in total. An Off-line protocol was introduced in order to detect the Set-up errors in patient positioning. The cases of interest were the following: Head and Neck, Thorax and Pelvis. In this protocol the Radiation Oncologist examined the acquired Portal Films and compared them with the digital reconstructed radiograms (DRRs). Patient shifts were applied in order improve the patient positioning accuracy whenever it was considered necessary. A large number of related parameters was noted for each imaging session. Additionally, the ‘Van Herk’ formula was used to calculate the CTV to PTV Margins for every treatment case. Finally, the margins that were calculated were compared with the margins that are being used by the physicians in the’ ATTIKON’ Radiotherapy Department, to evaluate the adequate dosimetric coverage of the targets and the adequate protection of normal tissue volumes during patient irradiation.