Related Experiment Video
Updated: Jan 19, 2026
06:51
Dosimetry for Cell Irradiation using Orthovoltage 40-300 kV X-Ray Facilities
Published on: February 20, 2021
5.5K
Phantom design and dosimetric characterization for multiple simultaneous cell irradiations with active pencil beam
Monika Clausen1, Suphalak Khachonkham2,3, Sylvia Gruber2
1Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria. monika.clausen@meduniwien.ac.at.
Radiation and Environmental Biophysics
|September 22, 2019
Summary
A new phantom for particle beam studies was dosimetrically characterized, showing good agreement with Monte Carlo simulations. This phantom is essential for accurate relative biological effectiveness (RBE) experiments in cancer treatment.
Area of Science:
- Medical Physics
- Radiation Oncology
- Radiobiology
Background:
- In vitro studies using cell lines in particle beams require accurate dosimetry.
- Existing phantoms may not adequately support simultaneous irradiation at multiple positions.
- Heterogeneous phantoms are crucial for simulating complex treatment scenarios.
Purpose of the Study:
- To perform a detailed dosimetric characterization of a newly designed phantom for horizontal particle beams.
- To evaluate the phantom's suitability for in vitro radiobiology experiments.
- To compare dose calculations from different treatment planning system algorithms against experimental measurements.
Main Methods:
- Designed and utilized a novel heterogeneous phantom for simultaneous multi-position irradiation.
- Conducted CT scans, dose calculations using RayStation (Pencil Beam and Monte Carlo algorithms), and proton beam delivery.
- Performed experimental dosimetry with ionization chambers and EBT3 films, alongside LETd distribution analysis.
Main Results:
- Measured depth dose distributions closely matched Monte Carlo-based treatment planning system (TPS) data.
- Pencil Beam algorithm showed a 4% higher absorbed dose compared to ionization chamber measurements at the Bragg peak's deepest point.
- A strong correlation between relative biological effectiveness (RBE) and LETd was observed, with RBE10 values ranging from 1.4 to 1.8.
Conclusions:
- Rigorous dosimetric characterization of phantoms is critical for reliable RBE data in particle therapy.
- The designed phantom enables accurate dosimetry under non-reference conditions.
- High dosimetric accuracy facilitates better understanding of physical versus biological uncertainties in RBE studies.
