Estimation of midpoint dose for cervical cancer patients using EPID

• Autorzy: Balan, G. , Chandrasekaran, A. R. , Velayudham, R. , Annamalai, G. , Ramachandran, M.
• Języki publikacji: EN

Abstrakty

EN

Purpose: To estimate the midpoint dose delivered to cervical cancer patients treated by conventional technique using Electronic Portal Imaging Device (EPID). Materials and Methods: Clinac 2100 equipped with aS500 EPID was used in this study. A methodology was developed to generate a Gy/Calibration Unit (CU) look up table for the determination of midpoint dose of patients. 25 patients of cervical cancer were included in this study and the delivered dose to the midpoint of the patients was estimated using EPID. The deviation between the prescribed and the measured dose was calculated and analysed. Results: EPID showed a linear response with increase in Monitor unit and the Gy/CU look up table was validated for different field sizes and depth. 250 fields were measured for 25 patients, 10 measurements per patient, weekly once and for 5 weeks. The results show that out of 250 measurements, 98% of the measurements are within ±5% and 83.2% are within ±3% for with a standard deviation of 1.66%. Conclusion: The outcome of this study proves the efficacy of this methodology for the estimation of midpoint dose using EPID with minimal effort, time and without any inconvenience to the patients unlike other in-vivo dosimeters.

Słowa kluczowe

EN

cervical cancer; EPID; in-vivo dosimeter; ion chamber

• Czasopismo: Polish Journal of Medical Physics and Engineering
• Rocznik: 2018
• Tom: Vol. 24, Iss. 3
• Strony: 103--108
• Opis fizyczny: Bibliogr. 17 poz., rys., tab.

Twórcy

autor

Balan, G.

• School of Advanced Sciences, Vellore Institute of Technology, Vellore-632 014, India,
• Department of Medical Physics, Government Arignar Anna Memorial Cancer Hospital and Research Institute, RCC, Kanchipuram- 631 552, India

autor

Chandrasekaran, A. R.

• School of Advanced Sciences, Vellore Institute of Technology, Vellore-632 014, India

autor

Velayudham, R.

• School of Advanced Sciences, Vellore Institute of Technology, Vellore-632 014, India

autor

Annamalai, G.

• Department of Medical Physics, Government Arignar Anna Memorial Cancer Hospital and Research Institute, RCC, Kanchipuram- 631 552, India

autor

Ramachandran, M.

• Mediclinic Middle East, Dubai, United Arab Emirates

Bibliografia

• [1] IAEA (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 Report Series no.398. IAEA, Vienna. 2000.
• [2] Vasile G, Vasile M, Duliu OG. In-vivo dosimetry measurements for breast radiation treatments. Romanian Rep Phys. 2012;64(3):728-736.
• [3] Van Dam J, Marinello G. Methods for in-vivo dosimetry in external radiotherapy. ESTRO booklet No.1. 2006.
• [4] van Elmpt W, McDermott L, Nijstenn S, et al. A literature review of electronic portal imaging for radiation dosimetry. Radiother Oncol. 2008;88(3):289-309.
• [5] Shrivastava SK, Mahantshetty U, Narayan K. Principles of radiation therapy in low-resource and well-developed settings, with particular reference to cervical cancer. Int J Gynaecol Obstet. 2015;131(S2):153-158.
• [6] Leal MA, Viegas C, Viamonte A, et.al. Thermoluminescent chip detector for in-vivo dosimetry in pelvis and head and neck cancer treatment. Appl Radiat Isot. 2010;68(4-5):795-798.
• [7] Evwierhurhoma OB, Ibitoye ZA, Ojieh CA, et al. Verification of entrance dose measurements with thermoluminescent dosimeters in conventional radiotherapy procedures delivered with Co-60 teletherapy machine. Ann Med Health Sci Res. 2015;5(6):409-412.
• [8] Seco J, Clasie B, Partridge M. Review on the characteristics of radiation detectors for dosimetry and imaging. Phys Med Biol. 2014;59(20):R303-R347.
• [9] Greer PB, Popescu C. Dosimetric properties of an amphorous silicon electronic portal imaging device for verification of dynamic intensity modulated radiation therapy. Med.Phys. 2003;30(7):1618-1627.
• [10] McCurdy BM, Luchka K, Pistorius S. Dosimetric investigation and portal dose image prediction using an amorphous silicon electronic portal imaging device. Med.Phys. 2001;28(6):911-924.
• [11] Winkler P, Hefner A, Georg D. Dose-response characteristics of an amorphous silicon EPID. Med Phys. 2005;32(10):3095-3105.
• [12] Camilleri J, Mazurier J, Franck D, et.al. Clinical results of an EPID- based in- vivo dosimetry method for pelvic cancers treated by intenstity modulated radio therapy. Phys Med. 2014;30(6):690-695.
• [13] Huyskens D, Van Dam J, Dutreix A. Mid plane dose determination using in-vivo dose measurements in combination with portal imaging. Phys Med Biol. 1994;39(7):1089-1102.
• [14] Morton JP, Bhat M, Williams T, Kovendy A. Clinical results of entrance dose in-vivo dosimetry for high energy photons in external beam radiotherapy using MOSFETs. Austral Phys Eng Sci Med. 2007;30(4):252-259.
• [15] Strojnik A. In-vivo dosimetry with diodes in rectal cancer patients. Radiol Onco. 2007;41(4):196-202.
• [16] Costa AM, Barbi GL, Bertucci EV, et al. In-vivo dosimetry with thermoluminescent dosimeters in external photon beam radiotherapy. Appl Radiat Isot. 2010;68(4-5):760-762.
• [17] Gandhi MA, Buzdar SA, Fatmi S. In-Vivo dosimetry with diode for the treatment of pelvic malignancies. Austin Oncol Case Rep. 2016;1(1):1004:1-4.

Identyfikatory

DOI

10.2478/pjmpe-2018-0014