Dosimetric comparison of VMAT, IMRT and conformal plans in medulloblastoma radiotherapy: Retrospective study


Thesis Type: Postgraduate

Institution Of The Thesis: Bursa Uludağ University, Sağlık Bilimleri Enstitüsü, Turkey

Approval Date: 2021

Thesis Language: Turkish

Student: Gözde Parlar

Supervisor: CANDAN DEMİRÖZ ABAKAY

Abstract:

In this study, virtual treatment plans were compared for these three techniques using IMRT, VMAT and 3BKRT treatment planning systems for 8 patients with medulloblastoma who had previously received radiotherapy treatment. Archive materials of 8 patients diagnosed with medulloblastoma who were treated in the Radiation Oncology Department of Bursa Uludağ University Faculty of Medicine were retrospectively obtained and virtual treatment plans were made. In the plans made, a dose of 36 Gy from 1.8 Gy 20 fractions per fraction was determined to be given to the patients. PTV-CTV and critical organs were contoured by doctors for virtual plans. In the plans, attention was paid to the isodose covering 95% of the target volume and protecting critical organs. Dose distributions were obtained with the DVHs in the plans created, and statistical analysis was performed using the Independent-Samples T Test and Mann Whitney U tests in paired comparisons and Anova and Kruskal Wallis tests in triple comparisons with the SPSS program. As a result, no significant difference was found for kidneys, liver and CI values, while the lowest dose of most of them was obtained from the VMAT technique. When the MU value was examined, 3BKRT superior, the lowest dose value was obtained. In the HI value, although the lowest mean value is 3KBRT, the minimum and maximum value is VMAT.