Dose Verification in Helical Tomotherapy Using 2D-Array Ion Chambers
Author Information
Author(s): Xu S, Xie C, Ju Z, Dai X, Gong H, Wang L, Yang J
Primary Institution: Department of Radiation Oncology, PLA General Hospital, Beijing, China
Hypothesis
To investigate the clinical usage of dose verification of Helical Tomotherapy plans by using 2D-array ion chambers.
Conclusion
The MatriXX with Multicube is a reliable system for measuring both absolute and relative dose distributions in helical Tomotherapy IMRT planning.
Supporting Evidence
- The dose distributions measured by the MatriXX 2D array were in good agreement with plans calculated by the Tomotherapy planning system.
- The discrepancy between the measured dose and predicted dose was within ±3%.
- The mean passing rates of 2 mm dose grid with γ-parameter ≤1 were 97.37% and 96.91% in coronal and sagittal directions, respectively.
Takeaway
This study shows that a special device can help doctors check if the right amount of radiation is given to patients during treatment.
Methodology
The study used a pixel-segmented ionisation chamber device and a Multicube phantom to measure dose distributions from ten selected Tomotherapy IMRT/IGRT head and neck plans.
Potential Biases
Potential biases may arise from the calibration and setup of the MatriXX device.
Limitations
The effective field-size of the MatriXX system limits its use for large IMRT fields.
Participant Demographics
Participants were ten patients with nasopharyngeal carcinoma.
Statistical Information
P-Value
p<0.05
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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