Radiation dosimetry

The purpose of this thesis is to validate the Monte Carlo algorithm for
electron radiotherapy in the Eclipse™ treatment planning system (TPS), and to
compare the accuracy of the Electron Monte Carlo algorithm (eMC) to the Pencil
Beam algorithm (PB) in Eclipse™. Dose distributions from GafChromic™ EBT3
film measurements were compared to dose distributions from eMC and PB
treatment plans. Measurements were obtained with 6MeV, 9MeV, and 12MeV
electron beams at various depths. A 1 cm thick solid water template with holes
for bone-like and lung-like plugs was used to create assorted configurations and
heterogeneities. Dose distributions from eMC plans agreed better with the film
measurements based on gamma analysis. Gamma values for eMC were
between 83%-99%, whereas gamma values for PB treatment plans were as low
as 38.66%. Our results show that using the eMC algorithm will improve dose
accuracy in regions with heterogeneities and should be considered over PB.

The purpose of this research is to compare the surface dose outside the treatment area for different breast cancer irradiation modalities using Thermoluminescence Dosimeters (TLDs). Five different modalities are included in this study: Accuboost, Photon boost, Electron boost, Strut-Adjusted Volume Implant (SAVI), and Mammosite Multi-lumen (ML).Six points of interest (POI) on the breast cancer patients had been selected for the TLDs placement. Data from 25 breast cancer patients at Lynn Cancer Institute of the Boca Raton Regional Hospital were included in the study. The measured percentage ranges of the averaged doses at the six POIs for the different modalities are: Sternum 0.26% - 3.26%, Shoulder 0.33% - 2.79%, Eye 0.26% - 1.32%, Thyroid 0.20% - 2.75%, CLB 0.2% - 5.46%, Lower Abdomen 0.16% - 2.25%.