Iranian Journal of Medical Physics

Iranian Journal of Medical Physics

Absorbed Dose Measurements for Teletheraphy Prediction of Superficial Dose Using Halcyon Linear Accelerator

Document Type : Original Paper

Authors
Raymond Limen Njinga 1
Adeneye O Samuel 2
Akinyode Ojumoola Ajimo 1
Christopher J Olowookere 1
1 Department of Physics, University of Medical Sciences Ondo, Ondo State, Nigeria
2 Department of Radio Biology, Radio Diagnosis and Radiotherapy, College of Medicine University of Lagos/NSIA-LUTH Cancer Centre: Idiaraba, Lagos, Nigeria
10.22038/ijmp.2023.64557.2107
Abstract
Introduction: Measurement of entrance dose and dose at different depth is essential to avoid over dose and under dose of patients. The aim of this study is to verify the variation in the absorbed dose using a water equivalent material.
Material and Methods: The plastic phantom was arranged on the couch of the halcyon linear accelerator by Varian with the farmer ionization chamber inserted and connected to the electrometer. The image of the setup was taken using the High-Quality Single 1280x1280x16 higher on the service mode, to check the alignment with the isocenter. The beam quality TPR20,10 (Tissue phantom ratio) was done to check the beam quality of the machine at a field size of 10 cm x 10 cm.  The calibration was done using SAD type set-up at a depth of 5 cm. This process was repeated for ten consecutive weeks and the values recorded.
Results: The results of the beam output for the teletherapy machine were satisfactory and accepted in comparison with the commissioned measurement of 0.62. The beam quality TPR20,10 (Tissue phantom ratio) was reasonable with respect to the beam quality of the machine at a field size of 10 cm x 10 cm.
Conclusion: The results of the beam quality and the absorbed dose rate showed a good consistency over the period of ten weeks with the commissioned measurement value.
Keywords
Linear Accelerator Multi
Leaf Collimator Volumetric Modulated Arc Therapy Drum Phantom
Subjects
  1. Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, et al. Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2021;71(3):209–
  2. Sousa R V, Sousa R V. Dose Rate Influence on Deep Dose Deposition Using a 6 MV X-Ray Beam From a Linear Accelerator. 2009;292–
  3. Pokhrel D, Webster A, Stephen J, St Clair W. SBRT treatment of abdominal and pelvic oligometastatic lymph nodes using ring‐mounted Halcyon Linac. J Appl Clin Med Phys. 2021;22(6):162–
  4. Sun T, Lin X, Zhang G, Qiu Q, Li C, Yin Y. Treatment planning comparison of volumetric modulated arc therapy with the trilogy and the Halcyon for bilateral breast cancer. Radiat Oncol. 2021;16(1):1–
  5. Georg D, Knöös T, McClean B. Current status and future perspective of flattening filter free photon beams. Med Phys. 2011;38(3):1280–
  6. Kim H, Huq MS, Lalonde R, Houser CJ, Beriwal S, Heron DE. Early clinical experience with Varian halcyon V2 linear accelerator: dual‐isocenter IMRT planning and delivery with portal dosimetry for gynecological cancer treatments. J Appl Clin Med Phys. 2019;20(11):111–
  7. Ardekani MA, Haghparast M, Nourollahi S, Refahi S. Design of a slab phantom for breast dosimetry applications. J Cancer Res Ther. 2018;14(5):1126–
  8. Wickman G, Johansson B, Bahar-gogani J, Holmström T, Grindborg JE, Johansson B, et al. Liquid ionization chambers for absorbed dose measurements in water at low dose rates and intermediate photon energies Liquid ionization chambers for absorbed dose measurements in water at low dose rates and intermediate photon energies. 2013;900(1998).
  9. Andreo P, Seuntjens JP, Podgorsak EB. Chapter 9 Calibration of Photon and Electron Beams. Radiation Oncology. 2006. 1–95 p.
  10. Andreo P. Calibration of Photon and Electron Beams. Rev Radiat Oncol Phys a Handb Teach students. 2005;301–
  11. Seuntjens J, Olivares M, Evans M, Podgorsak E. Absorbed dose to water reference dosimetry using solid phantoms in the context of absorbed‐dose protocols. Med Phys. 2005;32(9):2945–
  12. Andreo P, Huq MS, Westermark M, Song H, Tilikidis A, DeWerd L, et al. Protocols for the dosimetry of high-energy photon and electron beams: a comparison of the IAEA TRS-398 and previous international Codes of Practice. Phys Med Biol. 2002;47(17):3033.
  13. Organization WH. Absorbed dose determination in external beam radiotherapy. An international code of practice for dosimetry based on standards of absorbed dose to water. 2004;
  14. Huq MS, Andreo P, Song H. Comparison of the IAEA TRS-398 and AAPM TG-51 absorbed dose to water protocols in the dosimetry of high-energy photon and electron beams. Phys Med Biol. 2001;46(11):2985.
  15. Slab Phantom. 2011;4182011.
  16. Niamatullah SN. Predictors of Outcome and Survival In Prostate Cancer – Data From Tertiary Care Urology Institute In Pakistan. Hematol Transfus Cell Ther. 2021;43.
  17. Stancu E, Vancea C, Valenta J, Zeman J, Badita E, Scarisoreanu A. Absorbed dose to water measurements in high energy electron beams using different plane parallel chambers. Rom Reports Phys. 2015;67(3):1152–
  18. Beir VII. Health risks from exposure to low levels of ionizing radiation. Natl Acad Rep Br. 2005;
  19. Sruti RN, Islam MM, Rana MM, Bhuiyan MMH, Khan KA, Newaz MK, et al. Measurement of percentage depth dose of a linear accelerator for 6 MV and 10 MV photon energies. Nucl Sci Appl. 2015;24(1).
  20. Florio M, Bastianin A, Castelnovo P. The socio-economic impact of a breakthrough in the particle accelerators’ technology: a research agenda. Nucl Instruments Methods Phys Res Sect A Accel Spectrometers, Detect Assoc Equip. 2018;909:21–

 

 

 

 

 

Iranian Journal of Medical Physics
Volume 21, Issue 4 - Serial Number 4
July and August 2024
Pages 265-271

  • Receive Date 25 March 2022
  • Revise Date 05 July 2024
  • Accept Date 20 June 2023