A Suitably Designed Lip Applicator for Radiation Therapy of Lips Carcinoma

Document Type : مقاله کوتاه

Authors

1 Associate Professor, Department of Medical Physics and Medical Engineering, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

2 PhD Student, Medical Students Research Center, Department of Medical Physics and Medical Engineering, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran

3 PhD Student, Department of Medical Physics, School of Medicine, Ahwaz Jundishapour University of Medical Sciences, Ahwaz, Iran

Abstract

Background: The aim of this study was to evaluate a novel boosting technique in radiation therapy of lip carcinoma using a suitably designed lip applicator, called (in this study) internal dose enhancer tool.Methods: The internal dose enhancer tool was designed with proper thickness of lead for reducing transmission to tissues located beyond the lips. A 0.5 cm thickness of polystyrene was used to cover the lead and reduce the backscattered electron dose, while an opening in the polystyrene layer allowed electrons to reach the target. Monte-Carlo models of 6 and 8 MeV electron beams were developed using BEAMnrc code and were validated against experimental measurements. Using the developed models, dose distributions in a lip phantom were calculated and the effect of an internal dose enhancer tool on target dose enhancement was evaluated.Findings: Using the internal dose enhancer tool, the maximum dose enhancement as a percentage of dose at dmax of the unshielded field were 57.6% and 36.1% for 6 and 8 MeV beams, respectively. The best outcome was achieved for lip thickness of less than 1.5 cm and target thickness of less than 1 cm. For lateral dose coverage of planning target volume (PTV), the 80% isodose curve at the lip-internal dose enhancer tool interface showed a 12 mm expansion, compared to the unshielded field.Conclusion: This study showed that a conformal external beam radiation therapy (EBRT) of lip is possible by using an internal dose enhancer tool. This boosting method is especially applicable to cases in which other treatment modalities, such as brachytherapy, faces limitations.

Keywords

References

  1. Regezi JA, Sciubba JJ, Jordan RCK. Oral pathology: clinical pathologic correlations. 2nd ed. Philadelphia, PA: Saunders; 1994.
  2. Bilkay U, Kerem H, Ozek C, Gundogan H, Guner U, Gurler T, et al. Management of lower lip cancer: a retrospective analysis of 118 patients and review of the literature. Ann Plast Surg 2003; 50(1): 43-50.
  3. Zitsch RP, III. Carcinoma of the lip. Otolaryngol Clin North Am 1993; 26(2): 265-77.
  4. Khan FD. The physics of radiation therapy. 4th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009.
  5. Kwan W, Wilson D, Moravan V. Radiotherapy for locally advanced basal cell and squamous cell carcinomas of the skin. Int J Radiat Oncol Biol Phys 2004; 60(2): 406-11.
  6. Dasher B, Wiggers N, Vann AM. Portal design in radiation therapy. 1st ed. South Houston, TX: DWV Enterprises; 1994.
  7. Sykes AJ, Allan E, Irwin C. Squamous cell carcinoma of the lip: the role of electron treatment. Clin Oncol (R Coll Radiol ) 1996; 8(6): 384-6.
  8. Schleicher UM, Andreopoulos D, Ammon J. Palliative radiotherapy in recurrent head-and-neck tumors by a percutaneous superfractionated treatment schedule. Int J Radiat Oncol Biol Phys 2001; 50(1): 65-8.
  9. Shokrani P, Baradaran-Ghahfarokhi M, Khoramizadeh MK. A novel approach in electron beam radiation therapy of lips carcinoma: a Monte Carlo study. Med Phys 2013; 40(4): 041720.
  10. Spezi E, Lewis G. An overview of Monte Carlo treatment planning for radiotherapy. Radiat Prot Dosimetry 2008; 131(1): 123-9.
  11. Mosleh-Shirazi MA, Hadad K, Faghihi R, Baradaran-Ghahfarokhi M, Naghshnezhad Z, Meigooni AS. EchoSeed Model 6733 Iodine-125 brachytherapy source: improved dosimetric characterization using the MCNP5 Monte Carlo code. Med Phys 2012; 39(8): 4653-9.
  12. Das IJ, Cheng CW, Mitra RK, Kassaee A, Tochner Z, Solin LJ. Transmission and dose perturbations with high-Z materials in clinical electron beams. Med Phys. 2004; 31(12): 3213-21.
  13. Hu YA, Song H, Chen Z, Zhou S, Yin FF. Evaluation of an electron Monte Carlo dose calculation algorithm for electron beam. J Appl Clin Med Phys 2008; 9(3): 2720.
  14. Chow JC, Grigorov GN. Monte Carlo simulation of backscatter from lead for clinical electron beams using EGSnrc. Med Phys 2008; 35(4): 1241-50.
  15. Kawrakow I, Rogers DWO. The EGSnrc code system: Monte Carlo simulation of electron and photon transport. Technical Report No. PIRS-701. Ottawa, ON: National Research Council of Canada; 2000.
  16. International Atomic Energy Agency. Treatment machines for external beam radiotherapy. A handbook for teachers and students. Vienna, Austria: IAEA; 2005.
  17. Verhaegen F, Seuntjens J. Monte Carlo modelling of external radiotherapy photon beams. Phys Med Biol 2003; 48(21): R107-R164.
  18. International Atomic Energy Agency. Absorbed dose determination in external beam radiotherapy: an international code of practice for dosimetry based on standards of absorbed dose to water. Technical Reports Series no 398. Vienna, Austria: IAEA; 2000.
Journal of Isfahan Medical School
Volume 32, Issue 297 - Serial Number 297
July and August 2014
Pages 1310-1318

Files

History

  • Receive Date: 26 June 2014
  • Revise Date: 03 May 2024
  • Accept Date: 06 April 2022

Share

How to cite

Statistics