| Title |
Measurement and analysis of radiation doses to the tumour and healthy tissues during intensity-modulated treatment procedures |
| Translation of Title |
Apšvitos dozių augliui ir sveikiems audiniams matavimas bei analizė moduliuoto intensyvumo gydymo procedūrų metu. |
| Authors |
Milašius, Vilius |
| Full Text |
|
| Pages |
60 |
| Keywords [eng] |
out-of-field dose ; phantom ; intensity-modulated radiotherapy ; volumetric arc therapy ; radiochromic films |
| Abstract [eng] |
Prostate cancer (PCa) is the most prevalent malignancy among men worldwide. The PCa incident and mortality rates in the European Union are significantly lower than in the Baltic states, with rates more than twice as high in the latter. However, advancements in radiology and radiotherapy led to create more individualized treatment, improving life expectancy after the treatment. Despite the improved treatment planning approaches, dose calculation algorithms of the treatment planning systems (TPS) tend to underestimate the dose and insufficiently compute out-of-field doses beyond the in-field edge. During this study the reliability of the dose calculation algorithms used in a daily clinical practice was checked, paying special attention to the out-of-field region. The four different treatment plans: 2 intensity-modulated radiotherapy (IMRT) and 2 volumetric arc therapy (VMAT) technique plans were planned with the treatment planning system Eclipse for each technique using different dose calculation algorithms (AAA or Acuros XB). Comparison of the calculated doses with the treatment planning system was additionally measured with 2D radiochromic films RTQA2 dosimetry. The main study results showed that the highest difference (up to 51.4%) of four planned treatment plans was observed between different treatment planning techniques (IMRT vs. VMAT) since just a slight difference (up to 4.6%) between dose calculation algorithms was registered. Treatment planning system (TPS) calculations versus 2D dosimetry measurements revealed miscalculations of TPS by 30%. Due to the lack of accuracy, TPS not always can be trusted for the evaluation of out-of-field doses (or doses for critical organs or healthy tissues). |
| Dissertation Institution |
Kauno technologijos universitetas. |
| Type |
Master thesis |
| Language |
English |
| Publication date |
2024 |
