This study aims to measure the radial dose function and anisotropy function F(r, θ) of high Dose Rate (HDR) 192Ir source in a fabricated water-equivalent phantom using Gafchromic® EBT3 film and TLD-100H and to compare the results obtained with the MCNP5 calculated values. The phantom was fabricated using Perspex PMMA material. For, the EBT3 films with a required dimension and TLD-100H chips were placed at r=1, 2, 3, 5, and 10 cm from the source. The F(r, θ) measurements were carried out at r=1, 2, 3, 5, and 10 cm with the angle range from 10° to 170°. The result of from EBT3 film and TLD-100H was in good agreement (2.10%±1.99). Compared to MCNP5, the differences are within 0.31% to 11.47% for EBT3 film and 0.08% to 10.58% for TLD-100H. For the F(r, θ), an average deviation with the MCNP5 calculation is 4.94%±2.7. For both and F(r, θ), the effects are prominent at r=10 cm. At this distance, the response of both Gafchromic® EBT3 film and TLD-100H shows less sensitivity as the dose followed the inverse square law. This work demonstrates that Gafchromic® EBT3 film dosimeter and TLD-100H are suitable dosimeters in 192Ir dosimetric measurements at a radial distance of ˂5 cm

• Adelnia, A., & Fatehi, D. (2016). Estimation and evaluation of tissue inhomogeneity effect on dose distribution for high dose rate iridium 192 source Using Monte Carlo simulation and film dosimetery. Journal of Nuclear Medicine & Radiation Therapy, 7(6), Article 1000312. https://doi.org/10.4172/2155-9619.1000312

• Ayoobian, N., Asl, A. S., Poorbaygi, H., & Javanshir, M. R. (2016). Gafchromic film dosimetry of a new HDR 192Ir brachytherapy source. Journal of Applied Clinical Medical Physics, 17(2), 194-205. https://doi.org/10.1120/jacmp.v17i2.6005

• Bassi, S., Cummins, D., & McCavana, P. (2020). Energy and dose dependence of GafChromic EBT3-V3 film across a wide energy range. Reports of Practical Oncology and Radiotherapy, 25(1), 60-63. https://doi.org/10.1016/j.rpor.2019.12.007

• Borca, V. C., Pasquino, M., Russo, G., Grosso, P., Cante, D., Sciacero, P., Girelli, G., La Porta, M. R., & Tofani, S. (2013). Dosimetric characterization and use of GAFCHROMIC EBT3 film for IMRT dose verification. Journal of Applied Clinical Medical Physics, 14(2), 158-171. https://doi.org/10.1120/jacmp.v14i2.4111

• Buchapudi, R., Manickam, R., & Chandaraj, V. (2019). Experimental determination of radial dose function and anisotropy function of GammaMed plus 192Ir high-dose-rate brachytherapy source in a bounded water phantom and its comparison with egs-brachy Monte Carlo simulation. Journal of Medical Physics, 44(4), 246-253. https://doi.org/10.4103/jmp.JMP_60_19

• Chandola, R., Tiwari, S., Kowar, M., & Choudhary, V. (2010). Monte Carlo and experimental dosimetric study of the mHDR-v2 brachytherapy source. Journal of Cancer Research and Therapeutics, 6(4), 421-426. https://doi.org/10.4103/0973-1482.77068

• Chen, T. C., Stoebe, T. G., Horowitz, Y. S., & Oster, L. (2002). Role of impurities in the thermoluminescence of LiF:Mg,Cu,P. Radiation Protection Dosimetry, 100(1-4), 243-246. https://doi.org/10.1093/OXFORDJOURNALS.RPD.A005857

• Chiu-Tsao, S. T., Napoli, J. J., Davis, S. D., Hanley, J., & Rivard, M. J. (2014). Dosimetry for 131Cs and 125I seeds in solid water phantom using radiochromic EBT film. Applied Radiation and Isotopes, 92, 102-114. https://doi.org/10.1016/j.apradiso.2014.06.014

• de Almeida, C. E., Rodriguez, M., Vianello, E., Ferreira, I. H., & Sibata, C. (2002). An anthropomorphic phantom for quality assurance and training in gynaecological brachytherapy. Radiotherapy and Oncology, 63(1), 75-81. https://doi.org/10.1016/S0167-8140(02)00065-8

• DeWerd, L. A., Ibbott, G. S., Meigooni, A. S., Mitch, M. G., Rivard, M. J., Stump, K. E., Thomadsen, B. R., & Venselaar, J. L. M. (2011). A dosimetric uncertainty analysis for photon-emitting brachytherapy sources: Report of AAPM Task Group No. 138 and GEC-ESTRO. Medical Physics, 38(2), 782-801. https://doi.org/10.1118/1.3533720

• DeWerd, L. A., Liang, Q., Reed, J. L., & Culberson, W. S. (2014). The use of TLDs for brachytherapy dosimetry. Radiation Measurements, 71, 276-281. https://doi.org/10.1016/j.radmeas.2014.05.005

• Faghihi, R., & Street, M. (2015). Investigation of LiF, Mg and Ti (TLD-100) reproducibility. Journal of Biomedical Physics & Engineering, 5(4), 217-222.

• Fazli, Z., Sadeghi, M., Zahmatkesh, M. H., Mahdavi, S. R., & Tenreiro, C. (2013). Dosimetric comparison between three dimensional treatment planning system, Monte Carlo simulation and gel dosimetry in nasopharynx phantom for high dose rate brachytherapy. Journal of Cancer Research and Therapeutics, 9(3), 402-409. https://doi.org/10.4103/0973-1482.119316

• Fiandra, C., Fusella, M., Giglioli, F. R., Filippi, A. R., Mantovani, C., Ricardi, U., & Ragona, R. (2013). Comparison of Gafchromic EBT2 and EBT3 for patient‐specific quality assurance: cranial stereotactic radiosurgery using volumetric modulated arc therapy with multiple noncoplanar arcs. Medical Physics, 40(8), Article 082105. https://doi.org/10.1118/1.4816300

• Freire, L., Calado, A., Cardoso, J. V, Santos, L. M., & Alves, J. G. (2008). Comparison of LiF (TLD-100 and TLD-100H) detectors for extremity monitoring. Radiation Measurements, 43(2), 646-650. https://doi.org/https://doi.org/10.1016/j.radmeas.2007.12.013

• Ghiassi-Nejad, M., Jafarizadeh, M., Ahmadian-Pour, M. R., & Ghahramani, A. R. (2001). Dosimetric characteristics of 192Ir sources used in interstitial brachytherapy. Applied Radiation and Isotopes, 55(2), 189-195. https://doi.org/10.1016/S0969-8043(00)00375-4

• Granero, D., Vijande, J., Ballester, F., & Rivard, M. J. (2011). Dosimetry revisited for the HDR brachytherapy source model mHDR-v2. Medical Physics, 38(1), 487-494. https://doi.org/https://doi.org/10.1118/1.3531973

• Haworth, A., Butler, D. J., Wilfert, L., Ebert, M. A., Todd, S. P., Hayton, A. J. M., & Kron, T. (2013). Comparison of TLD calibration methods for 192 Ir dosimetry. Journal of Applied Clinical Medical Physics, 14(1), 258-272. https://doi.org/10.1120/jacmp.v14i1.4037

• Hsu, S. M., Wu, C. H., Lee, J. H., Hsieh, Y. J., Yu, C. Y., Liao, Y. J., Kuo, L. C., Liang, J. A., & Huang, D. Y. C. (2012). A study on the dose distributions in various materials from an Ir-192 HDR brachytherapy source. PLoS ONE, 7(9), Article e44528. https://doi.org/10.1371/journal.pone.0044528

• Kirisits, C., Rivard, M. J., Baltas, D., Ballester, F., De Brabandere, M., Van Der Laarse, R., Niatsetski, Y., Papagiannis, P., Paulsen Hellebust, T., Perez-Calatayud, J., Tanderup, K., Venselaar, J. L. M., & Siebert, F. A. (2014). Review of clinical brachytherapy uncertainties: Analysis guidelines of GEC-ESTRO and the AAPM q. Radiotherapy and Oncology, 110, 199-212. https://doi.org/10.1016/j.radonc.2013.11.002

• López, J. A., Donaire, J. T., & Alcalde, R. G. (2011). Monte Carlo dosimetry of the most commonly used 192 Ir high dose rate brachytherapy sources. Revista de Física Médica, 12(3), 159-168.

• Niroomand-Rad, A., Chiu-Tsao, S. T., Grams, M. P., Lewis, D. F., Soares, C. G., Van Battum, L. J., Das, I. J., Trichter, S., Kissick, M. W., Massillon-JL, G., Alvarez, P. E., & Chan, M. F. (2020). Report of AAPM Task group 235 radiochromic film dosimetry: An update to TG-55. Medical Physics, 47(12), 5986-6025. https://doi.org/https://doi.org/10.1002/mp.14497

• Palmer, A. L., Bradley, D. A., & Nisbet, A. (2014). Dosimetric audit in brachytherapy. The British Journal of Radiology, 87(1041), Article 20140105. https://doi.org/10.1259/bjr.20140105

• Palmer, A. L., Nisbet, A., & Bradley, D. A. (2013). Semi-3D dosimetry of high dose rate brachytherapy using a novel Gafchromic EBT3 film-array water phantom. Journal of Physics: Conference Series, 444(1), Article 012101. https://doi.org/10.1088/1742-6596/444/1/012101

• Patel, N. P., Majumdar, B., & Vijayan, V. (2010). Comparative dosimetry of GammaMed Plus high-dose rate 192Ir brachytherapy source. Journal of Medical Physics, 35(3), 137-143. https://doi.org/10.4103/0971-6203.66761

• Reinhardt, S., Hillbrand, M., Wilkens, J. J., & Assmann, W. (2012). Comparison of Gafchromic EBT2 and EBT3 films for clinical photon and proton beams. Medical Physics, 39(8), 5257-5262. https://doi.org/10.1118/1.4737890

• Rivard, M. J., Coursey, B. M., DeWerd, L. A., Hanson, W. F., Huq, M. S., Ibbott, G. S., Mitch, M. G., Nath, R., & Williamson, J. F. (2004). Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations. Medical Physics, 31(3), 633-674. https://doi.org/10.1118/1.1646040

• Sellakumar, P., Sathish Kumar, A., Supe, S. S., Anand, M. R., Nithya, K., & Sajitha, S. (2009). Evaluation of dosimetric functions for Ir-192 source using radiochromic film. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 267(10), 1862-1866. https://doi.org/https://doi.org/10.1016/j.nimb.2009.03.003

• Shukor, N. S. A., Musarudin, M., Abdullah, R., & Aziz, M. Z. A. (2020). Effects of different volumes of inhomogeneous medium to the radial dose and anisotropy functions in HDR brachytherapy. Journal of Physics: Conference Series, 1497(1), Article 012027. https://doi.org/10.1088/1742-6596/1497/1/012027

• Sina, S., Lotfalizadeh, F., Karimipourfard, M., Zaker, N., Amanat, B., Zehtabian, M., & Meigooni, A. S. (2015). Material-specific conversion factors for different solid phantoms used in the dosimetry of different brachytherapy sources. Iranian Journal of Medical Physics, 12(2), 109-120. https://doi.org/10.22038/ijmp.2015.4774

• Subhalaxmi, M., & Selvam, T. P. (2015). Phantom scatter corrections of radiochromic films in high-energy brachytherapy dosimetry: A Monte Carlo study. Radiological Physics and Technology, 8(2), 215-223. https://doi.org/10.1007/s12194-015-0310-9

• Uniyal, S. C., Naithani, U. C., & Sharma, S. D. (2011). Evaluation of Gafchromic EBT2 film for the measurement of anisotropy function for high-dose-rate 192Ir brachytherapy source with respect to thermoluminescent dosimetry. Reports of Practical Oncology and Radiotherapy, 16(1), 14-20. https://doi.org/10.1016/j.rpor.2010.11.003

• Wu, C. H., Liao, Y. J., Liu, Y. W. H., Hung, S. K., Lee, M. S., & Hsu, S. M. (2014). Dose distributions of an 192Ir brachytherapy source in different media. BioMed Research International, 2014, Article 946213. https://doi.org/10.1155/2014/946213