Multi-Institutional Study of End-to-End Dose Delivery Quality Assurance Testing for Image-Guided Brachytherapy Using a Gel Dosimeter



      To quantify dose delivery errors for high-dose-rate image-guided brachytherapy (HDR-IGBT) using an independent end-to-end dose delivery quality assurance test at multiple institutions. The novelty of our study is that this is the first multi-institutional end-to-end dose delivery study in the world.


      The postal audit used a polymer gel dosimeter in a cylindrical acrylic container for the afterloading system. Image acquisition using computed tomography, treatment planning, and irradiation were performed at each institution. Dose distribution comparison between the plan and gel measurement was performed. The percentage of pixels satisfying the absolute-dose gamma criterion was reviewed.


      Thirty-five institutions participated in this study. The dose uncertainty was 3.6% ± 2.3% (mean ± 1.96σ). The geometric uncertainty with a coverage factor of k = 2 was 3.5 mm. The tolerance level was set to the gamma passing rate of 95% with the agreement criterion of 5% (global)/3 mm, which was determined from the uncertainty estimation. The percentage of pixels satisfying the gamma criterion was 90.4% ± 32.2% (mean ± 1.96σ). Sixty-six percent (23/35) of the institutions passed the verification. Of the institutions that failed the verification, 75% (9/12) had incorrect inputs of the offset between the catheter tip and indexer length in treatment planning and 17% (2/12) had incorrect catheter reconstruction in treatment planning.


      The methodology should be useful for comprehensively checking the accuracy of HDR-IGBT dose delivery and credentialing clinical studies. The results of our study highlight the high risk of large source positional errors while delivering dose for HDR-IGBT in clinical practices.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Brachytherapy
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • DeWerd LA
        • Ibbott GS
        • Meigooni AS
        • et al.
        A dosimetric uncertainty analysis for photon-emitting brachytherapy sources: report of AAPM Task Group No. 138 and GEC-ESTRO.
        Med Phys. 2011; 38: 782-801
        • Elfrink RJ
        • Kolkman-Deurloo IK
        • van Kleffens HJ
        • et al.
        Quality control of brachytherapy equipment in the Netherlands and Belgium: current practice and minimum requirements.
        Radiother Oncol. 2002; 62: 95-102
        • Nath R
        • Anderson LL
        • Meli JA
        • et al.
        Code of practice for brachytherapy physics: report of the AAPM Radiation Therapy Committee Task Group No. 56. American Association of Physicists in Medicine.
        Med Phys. 1997; 24: 1557-1598
        • 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: 633-674
        • Healy B
        • Frantzis J
        • Murry R
        • et al.
        Results from a multicenter prostate IMRT dosimetry intercomparison for an OCOG-TROG clinical trial.
        Med Phys. 2013; 40071706
        • Molineu A
        • Hernandez N
        • Nguyen T
        • et al.
        Credentialing results from IMRT irradiations of an anthropomorphic head and neck phantom.
        Med Phys. 2013; 40022101
        • Okamoto H
        • Minemura T
        • Nakamura M
        • et al.
        Establishment of postal audit system in intensity-modulated radiotherapy by radiophotoluminescent glass dosimeters and a radiochromic film.
        Phys Med. 2018; 48: 119-126
        • Weber DC
        • Vallet V
        • Molineu A
        • et al.
        IMRT credentialing for prospective trials using institutional virtual phantoms: results of a joint European Organization for the Research and Treatment of Cancer and Radiological Physics Center project.
        Radiat Oncol. 2014; 9: 123
        • Duke SL
        • Tan LT
        • Jensen NBK
        • et al.
        Implementing an online radiotherapy quality assurance programme with supporting continuous medical education - report from the EMBRACE-II evaluation of cervix cancer IMRT contouring.
        Radiother Oncol. 2020; 147: 22-29
        • Kirisits C
        • Federico M
        • Nkiwane K
        • et al.
        Quality assurance in MR image guided adaptive brachytherapy for cervical cancer: final results of the EMBRACE study dummy run.
        Radiother Oncol. 2015; 117: 548-554
      1. A randomized, phase 3, double-blind study of chemoradiotherapy with or without pembrolizumab for the treatment of high-risk, locally advanced cervical cancer (KEYNOTE-A18/ENGOT-cx11/GOG-3047). Available at: Access date: 2022/06/16.

        • Awunor O
        • Berger D
        • Kirisits C
        A multicenter study to quantify systematic variations and associated uncertainties in source positioning with commonly used HDR afterloaders and ring applicators for the treatment of cervical carcinomas.
        Med Phys. 2015; 42: 4472-4483
      2. IAEA. New CRP: development of methodology for dosimetry audits in brachytherapy (E24023). Available at: Access date: 2022/06/16.

        • Palmer AL
        • Bradley DA
        • Nisbet A
        Dosimetric audit in brachytherapy.
        Br J Radiol. 2014; 8720140105
        • Krause F
        • Risske F
        • Bohn S
        • et al.
        End-to-end test for computed tomography-based high-dose-rate brachytherapy.
        J Contemp Brachytherapy. 2018; 10: 551-558
        • Okamoto H
        • Nakamura S
        • Nishioka S
        • et al.
        Independent assessment of source position for gynecological applicator in high-dose-rate brachytherapy.
        J Contemp Brachytherapy. 2017; 9: 477-486
        • Persson M
        • Nilsson J
        • Carlsson Tedgren A
        Experience of using MOSFET detectors for dose verification measurements in an end-to-end (192)Ir brachytherapy quality assurance system.
        Brachytherapy. 2018; 17: 227-233
        • Bassi S
        • Berrigan L
        • Zuchora A
        • et al.
        End-to-end dosimetric audit: a novel procedure developed for Irish HDR brachytherapy centres.
        Phys Med. 2020; 80: 221-229
        • Tachibana H
        • Watanabe Y
        • Mizukami S
        • et al.
        End-to-end delivery quality assurance of computed tomography-based high-dose-rate brachytherapy using a gel dosimeter.
        Brachytherapy. 2020; 19: 362-371
        • Roue A
        • Ferreira IH
        • Van Dam J
        • et al.
        The EQUAL-ESTRO audit on geometric reconstruction techniques in brachytherapy.
        Radiother Oncol. 2006; 78: 78-83
        • Roue A
        • Venselaar JL
        • Ferreira IH
        • et al.
        Development of a TLD mailed system for remote dosimetry audit for (192)Ir HDR and PDR sources.
        Radiother Oncol. 2007; 83: 86-93
        • Watanabe Y
        • Mizukami S
        • Eguchi K
        • et al.
        Dose distribution verification in high-dose-rate brachytherapy using a highly sensitive normoxic N-vinylpyrrolidone polymer gel dosimeter.
        Phys Med. 2019; 57: 72-79
        • Adamson J
        • Carroll J
        • Trager M
        • et al.
        Delivered dose distribution visualized directly with onboard kV-CBCT: proof of principle.
        Int J Radiat Oncol Biol Phys. 2019; 103: 1271-1279
        • Yeo UJ
        • Taylor ML
        • Dunn L
        • et al.
        A novel methodology for 3D deformable dosimetry.
        Med Phys. 2012; 39: 2203-2213
        • Hayashi SI
        • Kawamura H
        • Usui S
        • et al.
        Influence of magnesium chloride on the dose-response of polyacrylamide-type gel dosimeters.
        Radiol Phys Technol. 2018; 11: 375-381
        • De Deene Y
        Essential characteristics of polymer gel dosimeters.
        J Phys. 2004; 3: 34-57
        • Pantelis E
        • Karlis AK
        • Kozicki M
        • et al.
        Polymer gel water equivalence and relative energy response with emphasis on low photon energy dosimetry in brachytherapy.
        Phys Med Biol. 2004; 49: 3495-3514
        • Baldock C
        • Murry P
        • Kron T
        Uncertainty analysis in polymer gel dosimetry.
        Phys Med Biol. 1999; 44: N243-N246
      3. JCGM100:2008. Evaluation of measurement data-Guide to the expression of uncertainty in measurement. International Organization for Standardization (ISO), Joint Committee for Guides in Metrology. Access date: 2022/06/16.

        • Miften M
        • Olch A
        • Mihailidis D
        • et al.
        Tolerance limits and methodologies for IMRT measurement-based verification QA: recommendations of AAPM Task Group No. 218.
        Med Phys. 2018; 45: e53-e83
        • Thomadsen BR
        • Erickson BA
        • Eifel PJ
        • et al.
        A review of safety, quality management, and practice guidelines for high-dose-rate brachytherapy: executive summary.
        Pract Radiat Oncol. 2014; 4: 65-70
        • Melhus C.S.
        • Rivard M.J.
        Approaches to calculating AAPM TG-43 brachytherapy dosimetry parameters for 137Cs, 125I, 192Ir, 103Pd, and 169Yb sources.
        Med Phys. 2006; 33: 1729-1737
        • Deene YD
        Essential characteristics of polymer gel dosimeters.
        J Phys. 2004; 3: 34-57
        • Tanderup K
        • Beddar S
        • Andersen CE
        • et al.
        In vivo dosimetry in brachytherapy.
        Med Phys. 2013; 40070902
        • Fonseca GP
        • Johansen JG
        • Smith RL
        • et al.
        In vivo dosimetry in brachytherapy: requirements and future directions for research, development, and clinical practice.
        Phys Imaging Radiat Oncol. 2020; 16: 1-11
        • Kertzscher G
        • Rosenfeld A
        • Beddar S
        • et al.
        In vivo dosimetry: trends and prospects for brachytherapy.
        Br J Radiol. 2014; 8720140206
        • Kirisits C
        • Rivard MJ
        • Baltas D
        • et al.
        Review of clinical brachytherapy uncertainties: analysis guidelines of GEC-ESTRO and the AAPM.
        Radiother Oncol. 2014; 110: 199-212
        • Tanderup K
        • Nesvacil N
        • Potter R
        • et al.
        Uncertainties in image guided adaptive cervix cancer brachytherapy: impact on planning and prescription.
        Radiother Oncol. 2013; 107: 1-5