Tomotherapy dose distribution verification using MAGIC-f polymer gel dosimetry.

Area of Science:

• Medical Physics
• Radiotherapy Dosimetry
• Magnetic Resonance Imaging

Background:

• Accurate measurement of three-dimensional (3D) radiation dose distribution is crucial for quality assurance in radiotherapy.
• TomoTherapy units deliver complex intensity-modulated radiation therapy (IMRT) plans, necessitating precise dose verification methods.

Purpose of the Study:

• To evaluate the efficacy of MAGIC-f gel for 3D dose distribution measurements.
• To assess the accuracy of MAGIC-f gel in measuring dose distributions from a tomotherapy unit.

Main Methods:

• Simulated a prostate IMRT irradiation in a MAGIC-f gel phantom.
• Delivered the simulated treatment using TomoTherapy equipment.
• Evaluated dose distribution using R2 distribution measurements via magnetic resonance imaging (MRI).

Main Results:

• High similarity observed between measured and treatment planning system (TPS)-expected isodoses.
• Agreement in relative absorbed dose profiles and dose-volume histograms.
• High gamma index pass rates achieved (88.4% for 3%/3 mm, 96.5% for 4%/4 mm).

Conclusions:

• MAGIC-f gel demonstrates significant promise for accurate 3D dose distribution measurements in radiotherapy.
• The results support the use of MAGIC-f gel as a reliable tool for quality assurance in tomotherapy.