Abstract
PURPOSE
Commission and treatment setup of Leipzig surface applicators, because of the steep
dose gradient and lack of robust immobilization, is challenging. We aim to improve
commissioning reliability by investigating the impact of detector choice on percentage
depth dose (PDD) verifications, and to enhance accuracy and reproducibility in calibration/treatment
setup through a simple and novel immobilization device.
METHODS AND MATERIALS
PDD distributions were measured with radiochromic films, optically stimulated luminescent
dosimeters (OSLDs), a diode detector, and both cylindrical and parallel plate ionization
chambers. The films were aligned to the applicators in parallel and transverse orientations.
PDD data from a benchmarking Monte Carlo (MC) study were compared with the measured
results, where surface doses were acquired from extrapolation. To improve setup accuracy
and reproducibility, a custom-designed immobilization prototype device was made with
cost-effective materials using a 3D printer.
RESULTS
The measured PDD data with different detectors had an overall good agreement (). The parallel plate ionization chamber reported unreliable doses for the smallest
applicator. There was no remarkable dose difference between the two film setups. The
two-in-one prototype device provided a rigid immobilization and a flexible positioning
of the applicator. It enhanced accuracy and reproducibility in calibration and treatment
setup.
CONCLUSION
We recommend using radiochromic films in the transverse orientation for a reliable
and efficient PDD verification. The applicator's clinical applicability has been limited
by a lack of robust immobilization. We expect this economical, easy-to-use prototype
device can promote the use of Leipzig applicators in surface brachytherapy.
Keywords
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 accessOne-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:
Subscribe to BrachytherapyAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- The American Brachytherapy society consensus statement for skin brachytherapy.Brachytherapy. 2020; 19: 415-426
- GEC-ESTRO ACROP recommendations in skin brachytherapy.Radiotherapy and Oncology. 2018; 126: 377-385
- Aspects of dosimetry and clinical practice of skin brachytherapy: The American Brachytherapy Society working group report.Brachytherapy. 2015; 14: 840-858
- Skin surface brachytherapy: A survey of contemporary practice patterns.Brachytherapy. 2017; 16: 223-229
- Surface brachytherapy: Joint report of the AAPM and the GEC-ESTRO Task Group No. 253.Medical Physics. 2020; 47: e951-e987
- Clinically-implementable template plans for multidwell treatments using Leipzig-style applicators in 192Ir surface brachytherapy.Brachytherapy. 2021; 20: 401-409
- Feasibility of using multiple-dwell positions in 192Ir Leipzig-style brachytherapy surface applicators to expand target coverage and clinical application.Brachytherapy. 2020; 19: 532-543
- Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations.Medical physics. 2004; 31: 633-674
- Surface applicators for high dose rate brachytherapy in AIDS-related Kaposi's sarcoma.International journal of radiation oncology, biology, physics. 1997; 39: 769-774
- Alternative effective modality of Leipzig applicator with an electron beam for the treatment of superficial malignancies.Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 2003; 508: 460-466
- Dosimetric characteristics of the Leipzig surface applicators used in the high dose rate brachy radiotherapy: Dosimetric characteristics of Leipzig applicator in HDR brachytherapy.Medical physics. 2004; 31: 3372-3377
- A dosimetric study of Leipzig applicators.International Journal of Radiation Oncology* Biology* Physics. 2005; 62: 579-584
- Impact of source position on high-dose-rate skin surface applicator dosimetry.Brachytherapy. 2016; 15: 650-660
- Dosimetric characterization and output verification for conical brachytherapy surface applicators. Part II. High dose rate 192Ir sources.Medical Physics. 2014; 41022104
- Clinical implementation and failure mode and effects analysis of HDR skin brachytherapy using Valencia and Leipzig surface applicators.Brachytherapy. 2015; 14: 293-299
- The dosimetric effect of variations in source position on treatments using Leipzig-style brachytherapy skin applicators.Biomedical Physics & Engineering Express. 2020; 6015031
- Radiochromic film dosimetry: recommendations of AAPM radiation therapy committee task group 55.Medical physics. 1998; 25: 2093-2115
- Report of AAPM task group 235 radiochromic film dosimetry: an update to TG-55.Medical physics. 2020; 47: 5986-6025
- Influence of the phantom material on the absorbed-dose energy dependence of the EBT3 radiochromic film for photons in the energy range 3 keV–18 MeV.Medical Physics. 2014; 41112103
- Optically stimulated luminescent dosimetry for high dose rate brachytherapy.Frontiers in oncology. 2012; 2: 91
- Characterization of optically stimulated luminescent dosimeters, OSLDs, for clinical dosimetric measurements.Medical physics. 2007; 34: 4594-4604
- In vivo measurements for high dose rate brachytherapy with optically stimulated luminescent dosimeters.Medical physics. 2013; 40071730
- AAPM TG 191: Clinical use of luminescent dosimeters: TLDs and OSLDs.Medical physics. 2020; 47: e19-e51
- Eine neue Flachkammerkonstruktion fur die Elektronendosimetrie Mediz.Physik 1993: 24 Wissenschaftliche Tagung der Deutschen Geselleschaft fur Medicinische Physik. 1993;
- The clinical impact of detector choice for beam scanning.Journal of applied clinical medical physics. 2014; 15: 174-193
- Output correction factors for small static fields in megavoltage photon beams for seven ionization chambers in two orientations—perpendicular and parallel.Medical Physics. 2020; 47: 242-259
- Overview on the dosimetric uncertainty analysis for photon-emitting brachytherapy sources, in the light of the AAPM Task Group No 138 and GEC-ESTRO report.Metrologia. 2012; 49: S253
- Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry.Medical physics. 2013; 40112102
- Dosimetric audit in brachytherapy.The British journal of radiology. 2014; 8720140105
- Novel simple templates for reproducible positioning of skin applicators in brachytherapy.Journal of Contemporary Brachytherapy. 2016; 8: 344
Article Info
Publication History
Accepted:
January 24,
2022
Received in revised form:
January 21,
2022
Received:
September 21,
2021
Footnotes
Disclosures: The authors report no proprietary or commercial interest in any product mentioned or concept discussed in this article.
Identification
Copyright
© 2022 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.
