Vol 29, No 3 (2024)
Research paper
Published online: 2024-06-19

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Effect of glass compression plate on EBT-XD film dosimetry for pretreatment quality assurance of stereotactic body radiotherapy

Sathiya Raj1, Nithya Shree1, K M Ganesh1
DOI: 10.5603/rpor.101095
Rep Pract Oncol Radiother 2024;29(3):357-361.

Abstract

Background: EBT-XD film is specially designed for high dose verifications such as stereotactic treatments. The dose response of the film can be affected by several factors, the curly nature of the film being one of them. In this study this curly nature of the film was investigated for stereotactic body radiotherapy (SBRT) plan verifications.

Materials and methods: For this study, 18 SBRT (11 prostate, 3 spines, and 4 lungs) cases were enrolled. For all the cases, volumetric modulated arc therapy (VMAT) plans were created in the Monaco treatment planning system and plan was delivered in Elekta Versa HD linear accelerator and delivered fluence was captured by EBT-XD films. All films were scanned with and without a compression plate. All the films were analyzed using the single-channel film method using the red channel.

Results: A significant difference in the gamma passing rates (GPR) for the films scanned with and without the compression plate was observed. The maximum percentage differences in GPR between using and not using a compression plate were 12.7% for 1% 1 mm, 8.1% for 2% 2 mm, 7.5% for 3% 2 mm, and 5% for 3% 3mm criteria. Similarly, the mean %difference in GPR was 5.8% for 1% 1 mm, 2.4% for 2% 2 mm, 1.6% for 3% 2 mm and 0.96% for 3% 3 mm criteria.

Conclusion: The results suggest that placing a compression plate over the film during scanning provided a great advantage in achieving a more accurate gamma passing rate irrespective of gamma criteria.

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References

  1. Mirza J, Park H, Park SY, et al. Use of radiochromic film as a high-spatial resolution dosimeter by Raman spectroscopy. Med Phys. 2016; 43(8Part1): 4520–4528.
  2. Chełmiński K, Bulski W, Georg D, et al. Energy dependence of radiochromic dosimetry films for use in radiotherapy verification. Rep Pract Oncol Radiother. 2010; 15(2): 40–46.
  3. Karsch L, Beyreuther E, Burris‐Mog T, et al. Dose rate dependence for different dosimeters and detectors: TLD, OSL, EBT films, and diamond detectors. Med Phys. 2012; 39(5): 2447–2455.
  4. Devic S, Tomic N, Lewis D. Reference radiochromic film dosimetry: Review of technical aspects. Phys Med. 2016; 32(4): 541–556.
  5. Marroquin E, González JH, López MC, et al. Evaluation of the uncertainty in an EBT3 film dosimetry system utilizing net optical density. J Appl Clin Med Phys. 2016; 17(5): 466–481.
  6. Xhaferllari I, Kim J, Liyanage R, et al. Clinical utility of Gafchromic film in an MRI-guided linear accelerator. Radiat Oncol. 2021; 16(1).
  7. Méndez I, Rovira-Escutia J, Casar B. A protocol for accurate radiochromic film dosimetry using Radiochromic.com. Radiol Oncol. 2021; 55(3): 369–378.
  8. Palmer A, Bradley D, Nisbet A. Evaluation and mitigation of potential errors in radiochromic film dosimetry due to film curvature at scanning. J Appl Clin Med Phys. 2015; 16(2): 425–431.
  9. International Atomic Enery Agency. Absorbed Dose Determination in External Beam Radiotherapy. Tech Rep Ser. 2024; 398(Rev. 1).
  10. Palmer A, Bradley D, Nisbet A. Evaluation and implementation of triple‐channel radiochromic film dosimetry in brachytherapy. J Appl Clin Med Phys. 2014; 15(4): 280–296.