| Titre : | Amélioration du protocole image et diminution de dose au CT-simulateur pour le traitement en radiothérapie de la prostate. |
| Auteurs : | Fatah BAKKA, Auteur ; Jean-Marc Denis, Promoteur |
| Type de document : | Travail de fin d'études |
| Editeur : | Woluwe-Saint-Lambert : Haute École Léonard de Vinci, 2021 |
| Langues: | Français |
| Index. décimale : | TFE - Imagerie médicale |
| Résumé : |
Ct-Scan simulator is the first step and the base of treatment planning. It provides high quality images that will be used firstly by radiation oncologists to outline the targets and organs at risk. Secondly by medical physicists to figure out the best way to deliver the prescribed dose to the targets and the lowest possible dose to healthy tissues. And finally, by the RTT every day during the treatment as a reference to match it with the daily position of the patient, achieving a high precision targeting. A previous study realized by J. Mukuralinda showed that Ct-Scan delivers a high dose that can’t be ignored. Therefore, the aim of this study is to synthesize the protocols used in the center and their parameters. And then, see how they influence the dose and if there’s a way to optimize it without influencing the image’s quality. In this study, we worked on a Toshiba Aquilion LB, and we used a cheese phantom to acquire HU variations depending on mAs selected, and SNR. A Catphan700 was used to evaluate the image quality with the help of Image J software and an Alderson phantom to see what images on a patient would look like.
CTDIvol and DLP values varied the most with the length scanned depending on the nature of the tumors and their localizations. We focused on the protocol ‘prostate 2mm’, at first our values of CTDIvol and DLP were 51,23mGy and 2149,78mGy.cm which is significantly higher than the other centers. Next step was to scan the phantom several times with various mAs values in order to evaluate image quality’s parameters (high and low contrast resolutions and MTF), after being sure that neither the collimation thickness nor the mAs variations have an impact on the UH-DE curve. As a conclusion, to reduce the dose with keeping a similar image quality we recommend changing mA value to 200-250, and a collimation thickness of 16x2mm and keep all the other parameters. This represents a decrease of 45% of the dose. |
| Accès : | Identifiez-vous avant d'accéder au document électronique |
| Disponible en ligne : | Oui |
| Lieu du stage : | Cliniques Universitaires Saint - Luc |
| Département du TFE : | Imagerie médicale |
Documents numériques (1)
 TFE imagerie médicale Adobe Acrobat PDF |
