In vivo Dose Measurement in Cervical Cancer Brachytherapy Using Dysprosium-doped Calcium Sulfate Thermoluminescent Dosimeters: A Phantom Study
Abstract
Aims: High-dose-rate (HDR) brachytherapy (BT) is an important part of the treatment of cervical cancer. Although there have been advances in three-dimensional image-guided treatment planning systems (TPSs), uncertainties in applicator positioning and anatomical variations can produce discrepancies in planned and delivered doses. This study aimed to evaluate the clinical feasibility and reliability of dysprosium-doped calcium sulfate (CaSO4:Dy) Teflon thermoluminescent dosimeters (TLDs) for independent dose verification in Co-60 HDR cervical BT. Materials and Methods: For calibration, the CaSO4:Dy Teflon TLD discs were held at a 5-cm depth in a phantom to closely mimic the conditions of dose measurements in a phantom. We specially constructed a phantom compatible with vaginal cylinders and Fletcher–Suit applicators to place TLDs at clinically significant sites. The measured doses were compared with TPS-calculated values by uncertainty analysis and statistical evaluation. Results: In-depth phantom measurements demonstrated that, for the same delivered dose, the response of CaSO4:Dy TLDs at 1-cm and 5-cm depth in the phantom differed by only about 4%. The TLD system demonstrated a combined uncertainty of 11.80% (c = 2), with absolute mean deviation ranging from 6% to 9% across all measurement points. Bland–Altman analysis demonstrates that more than 95% of the paired observations were distributed within the limit. Conclusion: The results confirm that with proper calibration, CaSO4:Dy Teflon TLD discs could also be a useful and trustworthy tool for independent dose verification in HDR BT. This approach can enhance routine quality assurance practices and improve confidence in dose delivery accuracy.
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BibTeX
@article{sharma2026vivo,
title = {{In vivo Dose Measurement in Cervical Cancer Brachytherapy Using Dysprosium-doped Calcium Sulfate Thermoluminescent Dosimeters: A Phantom Study}},
author = {Prabhat Krishna Sharma and Saral Kumar Gupta and Devesh Gupta},
journal = {Journal of Medical Physics},
year = {2026},
month = jul,
doi = {10.4103/jmp.jmp_107_26},
url = {https://doi.org/10.4103/jmp.jmp_107_26},
note = {CC BY-NC-SA},
}
RIS
TY - JOUR
TI - In vivo Dose Measurement in Cervical Cancer Brachytherapy Using Dysprosium-doped Calcium Sulfate Thermoluminescent Dosimeters: A Phantom Study
AU - Prabhat Krishna Sharma
AU - Saral Kumar Gupta
AU - Devesh Gupta
PY - 2026
DA - 2026/07/01
JO - Journal of Medical Physics
DO - 10.4103/jmp.jmp_107_26
UR - https://doi.org/10.4103/jmp.jmp_107_26
AB - Aims: High-dose-rate (HDR) brachytherapy (BT) is an important part of the treatment of cervical cancer. Although there have been advances in three-dimensional image-guided treatment planning systems (TPSs), uncertainties in applicator positioning and anatomical variations can produce discrepancies in planned and delivered doses. This study aimed to evaluate the clinical feasibility and reliability of dysprosium-doped calcium sulfate (CaSO4:Dy) Teflon thermoluminescent dosimeters (TLDs) for independent dose verification in Co-60 HDR cervical BT. Materials and Methods: For calibration, the CaSO4:Dy Teflon TLD discs were held at a 5-cm depth in a phantom to closely mimic the conditions of dose measurements in a phantom. We specially constructed a phantom compatible with vaginal cylinders and Fletcher–Suit applicators to place TLDs at clinically significant sites. The measured doses were compared with TPS-calculated values by uncertainty analysis and statistical evaluation. Results: In-depth phantom measurements demonstrated that, for the same delivered dose, the response of CaSO4:Dy TLDs at 1-cm and 5-cm depth in the phantom differed by only about 4%. The TLD system demonstrated a combined uncertainty of 11.80% (c = 2), with absolute mean deviation ranging from 6% to 9% across all measurement points. Bland–Altman analysis demonstrates that more than 95% of the paired observations were distributed within the limit. Conclusion: The results confirm that with proper calibration, CaSO4:Dy Teflon TLD discs could also be a useful and trustworthy tool for independent dose verification in HDR BT. This approach can enhance routine quality assurance practices and improve confidence in dose delivery accuracy.
SN - 0971-6203
SN - 1998-3913
ER -