Fig 1.
Diagram of the scintillation detector: (A) Developed TRMLSD and (B) conventional scintillation detector with a mirror.
Fig 2.
Experimental Setup for (A) the TRMLSD and (B) EBT3 film. (C) The measured profiles normalized to the maximum pixel value. Radiations were delivered at 249 monitor units with a 10.0 × 10.0 cm2 field for three different ISO values (800, 1600, and 6400) for the TRMLSD.
Fig 3.
Analysis of the recorded scintillation distribution: (A) Signal of scintillation over time, recorded by the developed system. (B) Two-dimensional scintillation distribution captured by the HERO5 Black at 50.41 s.
Fig 4.
FBNR technique: (A) Original two-dimensional (2D) scintillation distribution, (B) 2D scintillation distribution after application of the FBNR technique.
Fig 5.
Procedure for geometric correction: (A) Original image, (B) image after lens correction, (C) image after perspective correction, and (D) two-dimensional scintillation distribution of the 10.0 × 10.0 cm2 field after geometric correction.
Fig 6.
Image of the solid water phantom, 5.0 cm above the prototype of the TRMLSD with a 10.0 × 10.0 cm2 field.
Fig 7.
20.0 × 20.0 cm2 open field measured by an ion chamber array at the depth of 5.0 cm in the water phantom with an SSD of 100.0 cm.
Fig 8.
Flowchart for measuring 2D dose distribution using the TRMLSD.
Fig 9.
Simple intensity-modulated plans: (A) Field type 1 and (B) Field type 2.
Fig 10.
Procedure for brightness dependency by distance: (A) Cumulative two-dimensional scintillation distribution, (B) profiles before the light-intensity correction, and (C) profiles after the light-intensity correction.
Table 1.
Output factor of an ionization chamber and TRMLSD for two ISO values.
Fig 11.
(A) Profiles of the 2D dose distribution for 10.0 × 10.0 cm2 open field, (B) Dose differences of the measurements of the 10.0 × 10.0 cm2 field with the corrected dose D (x, y), (C) Profiles of the 2D dose distribution for the IMRT plan. (D) Dose differences of measurements of IMRT plan and corrected dose D (x, y): calculated dose distribution corresponding to the TPS (denoted by the solid line), measured dose distribution corresponding to the EBT3 film (denoted by the squares), TRMLSD (denoted by the circles), and correction using PenumbraNet (deconvolved profile, denoted by the stars).
Fig 12.
Test results for (A) does linearity, (B) reproducibility, and (C) dose rate dependency of TRMLSD.
Fig 13.
PDD profile measured by the TRMLSD (denoted by stars), EBT3 film (denoted by squares), and ionization chamber (denoted by a dashed line) for a 6 MV X-ray.
TRMLSD and EBT3 film data were normalized to the ionization chamber data at a depth of 5.0 cm.
Table 2.
Beam profiles of 6 MV X-rays for a 5.0-cm-thick solid water phantom.
Fig 14.
(A) Scintillation signal over time for a simple intensity-modulated plan (field type 1). The accumulated 2D dose distribution of the TRMLSD at (B) 81.6, (C) 110.4, and (D) 127.2 s. (E) 2D dose distribution of the EBT3 film.
Table 3.
Gamma analysis between the TRMLSD and EBT3 film for different gamma criteria.
Fig 15.
Each column represents a different field in the clinical liver IMRT case.
The first row shows the normalized 2D dose distribution calculated by the treatment planning system (TPS). The second row shows the normalized 2D dose distribution acquired using the TRMLSD. The third row shows the gamma index maps with the passing rates for each plan. A 3%/3 mm gamma criteria suppressing 5% of the maximum dose and global normalization were used. The TPS data were used as the reference dataset for comparison.
Table 4.
Quantitative results of the gamma passing rate per field dose distribution with 2%/2 mm and 3%/3 mm gamma criteria for the 10 IMRT cases (Unit: %).
Table 5.
Gamma passing rate of accumulated dose with the TRMLSD and EBT3 film compared with the TPS.