Monte Carlo dosimetry for BEBIG Cobalt-60 brachytherapy source with gynecological applicator in the presence of inhomogeneities

Moradi, Farhad; Sani, Siti Fairus Abdul; Mahyuddin, Azman; Ung, Ngie Min; Bradley, David Andrew; Almugren, Kholoud; Rashid, Hairul Azhar Abdul

doi:10.2478/pjmpe-2024-0017

Abstract

Introduction: High-dose-rate (HDR) ⁶⁰Co brachytherapy necessitates accurate dose calculations to minimize normal tissue toxicity and late malignancy risks. Conventionally, the American Association of Physicists in Medicine (AAPM) Task Group 43 (TG-43) formalism, utilizing table-based dose superposition, has been employed for dose calculations, overlooking tissue inhomogeneity effects.

Material and methods: This study focuses on characterizing the high-dose-rate BEBIG ⁶⁰Co brachytherapy source, in combination with a gynecological applicator, using Monte Carlo simulations. The investigation is based on the model of the modified BEBIG ⁶⁰Co source (Co0.A86) implemented at the University of Malaya Medical Center. Dosimetric properties are evaluated according to AAPM TG-43 formalism, with validation against existing published data.

Results: Our investigation presents comprehensive MC dosimetric properties of the high-dose-rate BEBIG ⁶⁰Co brachytherapy source, highlighting its accuracy in dose calculations compared to established data. The study also examined the impact of the applicator on depth dose calculations within a Krieger phantom and explored the influence of various tissue inhomogeneities on the depth dose.

Conclusions: Our findings revealed that the applicator had a relatively minimal effect on the delivered dose, with only marginal differences observed. Furthermore, we investigated the depth doses along the central axis of the applicator, within a segment characterized by various tissue inhomogeneities where dose differences of up to 12% were observed, with the lowest and highest doses recorded within bone and adipose tissues, respectively. This study underscores the valuable role of MC simulations in estimating doses at locations where physical measurements are unfeasible, such as the intra-uterine tube surface, as well as in scenarios featuring tissue inhomogeneities.

References

Jones D. ICRU Report 50—Prescribing, Recording and Reporting Photon Beam Therapy. Medical Physics. 1994;21(6):833-834. https://doi.org/10.1118/1.597396
Search in Google Scholar Back to article
Nag S, Erickson B, Thomadsen B, et al. The American Brachytherapy Society recommendations for high-dose-rate brachytherapy for carcinoma of the cervix. Int J Radiat Oncol Biol Phys. 2000;48(1):201-211. https://doi.org/10.1016/S0360-3016(00)00497-1
Search in Google Scholar Back to article
Richter J, Baier K, Flentje M. Comparison of 60 Cobalt and 192 Iridium sources in high dose rate afterloading brachytherapy. Strahlenther Onkol. 2008;184(4):187-192. https://doi.org/10.1007/s00066-008-1684-y
Search in Google Scholar Back to article
Campos LT, de Almeida CEV. Monte Carlo dosimetry of the 60Co BEBIG high dose rate for brachytherapy. PLoS One. 2015;10(9). https://doi.org/10.1371/journal.pone.0139032
Search in Google Scholar Back to article
Grigsby PW, Georgiou A, Jeffrey FW, Perez CA. Anatomic variation of gynecologic brachytherapy prescription points. Int J Radiat Oncol Biol Phys. 1993;27(3):725-729. https://doi.org/10.1016/0360-3016(93)90402-H
Search in Google Scholar Back to article
Elhanafy OA, Das RK, Paliwal BR, Migahed MD, Sakr HA, Elleithy M. Anatomic variation of prescription points and treatment volume with fractionated high-dose rate gynecological brachytherapy. J Appl Clin Med Phys. 2002;3(1):1-5. https://doi.org/10.1120/jacmp.v3i1.2586
Search in Google Scholar Back to article
Co JL, Bojador MR, Mejia MBA, Ortin TTS, Ganzon DE. Interfraction variation and dosimetric changes in patients with cervical cancer treated with intracavitary brachytherapy. J Glob Oncol. 2017;4:1-7. https://doi.org/10.1200/JGO.2016.008557
Search in Google Scholar Back to article
Chernavsky NE, Morcos M, Wu P, Viswanathan AN, Siewerdsen JH. Technical assessment of a mobile CT scanner for image-guided brachytherapy. J Appl Clin Med Phys. 2019;20(10):187-200. https://doi.org/10.1002/acm2.12738
Search in Google Scholar Back to article
Moradi F, Ung NM, Khandaker MU, et al. Monte Carlo skin dose simulation in intraoperative radiotherapy of breast cancer using spherical applicators. Phys Med Biol. 2017;62(16):6550. https://doi.org/10.1088/1361-6560/aa7fe6
Search in Google Scholar Back to article
Setilo I, Oderinde OM, du Plessis FC. The effect of SSD, Field size, Energy and Detector type for Relative Output Factor measurement in small photon beams as compared with Monte Carlo simulation. Polish J Med Phys Eng. 2019;25(2):101-110. https://doi.org/10.2478/pjmpe-2019-0014
Search in Google Scholar Back to article
11 Fardi Z, Taherparvar P. A Monte Carlo investigation of the dose distribution for new I-125 low dose rate brachytherapy source in water and in different media. Polish J Med Phys Eng. 2019;25(1):15-22. https://doi.org/10.2478/pjmpe-2019-0003
Back to article
Moradi F, Khandaker MU, Alrefae T, Ramazanian H, Bradley DA. Monte Carlo simulations and analysis of transmitted gamma ray spectra through various tissue phantoms. Appl Radiat Isot. 2019;146:120-126. https://doi.org/10.1016/j.apradiso.2019.01.031
Search in Google Scholar Back to article
Granero D, Perez-Calatayud J, Ballester F. Dosimetric study of a new Co-60 source used in brachytherapy. Med Phys. 2007;34(9):3485-3488. https://doi.org/10.1118/1.2759602
Search in Google Scholar Back to article
Badry H, Oufni L, Ouabi H, Hirayama H. Monte Carlo dose calculation for HDR brachytherapy source using EGS5 code. Radiat Phys Chem. 2018;150:76-81. https://doi.org/10.1016/j.radphyschem.2018.04.025
Search in Google Scholar Back to article
Rivard MJ, Coursey BM, DeWerd LA, et al. Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations. Med Phys. 2004;31(3):633-674. https://doi.org/10.1118/1.1646040
Search in Google Scholar Back to article
Selvam TP, Bhola S. EGSnrc-based dosimetric study of the BEBIG HDR brachytherapy sources. Med Phys. 2010;37(3):1365-1370. https://doi.org/10.1118/1.3326948
Search in Google Scholar Back to article
White DR, Booz J, Griffith RV, Spokas JJ, Wilson IJ. ICRU Report 44: tissue substitutes in radiation dosimetry and measurement. J Int Comm Rad Units Meas. 1989;23. https://doi.org/10.1093/jicru/os23.1.Report44
Search in Google Scholar Back to article
Jamalludin Z, Jong WL, Malik RA, Rosenfeld A, Ung NM. Characterization of MOSkin detector for in vivo dose verification during Cobalt-60 high dose-rate intracavitary brachytherapy. Phys Med. 2019;58:1-7. https://doi.org/10.1016/j.ejmp.2019.01.010
Search in Google Scholar Back to article

Monte Carlo dosimetry for BEBIG Cobalt-60 brachytherapy source with gynecological applicator in the presence of inhomogeneities

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