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. 2014 Mar;6(1):45-53.
doi: 10.5114/jcb.2014.40770. Epub 2014 Feb 19.

Dosimetric Characteristics of a New Unit for Electronic Skin Brachytherapy

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Free PMC article

Dosimetric Characteristics of a New Unit for Electronic Skin Brachytherapy

Teresa Garcia-Martinez et al. J Contemp Brachytherapy. .
Free PMC article

Abstract

Purpose: Brachytherapy with radioactive high dose rate (HDR) (192)Ir source is applied to small skin cancer lesions, using surface applicators, i.e. Leipzig or Valencia type. New developments in the field of radiotherapy for skin cancer include electronic brachytherapy. This technique involves the placement of an HDR X-ray source close to the skin, therefore combining the benefits of brachytherapy with the reduced shielding requirements and targeted energy of low energy X-rays. Recently, the Esteya(®) Electronic Brachytherapy System (Esteya EBS, Elekta AB-Nucletron, Stockholm, Sweden) has been developed specifically for HDR brachytherapy treatment of surface lesions. The system provides radionuclide free HDR brachytherapy by means of a small 69.5 kV X-ray source. The purpose of this study is to obtain the dosimetric characterization required for clinical implementation, providing the detailed methodology to perform the commissioning.

Material and methods: Flatness, symmetry and penumbra, percentage of depth dose (PDD), kV stability, HVL, output, spectrum, linearity, and leakage have been evaluated for a set of applicators (from 10 mm to 30 mm in diameter).

Results: Flatness and symmetry resulted better than 5% with around 1 mm of penumbra. The depth dose gradient is about 7%/mm. A kV value of 68.4 ± 1.0 kV (k = 1) was obtained, in good agreement with manufacturer data (69.5 kV). HVL was 1.85 mm Al. Dose rate for a typical 6 Gy to 7 Gy prescription resulted about 3.3 Gy/min and the leakage value was < 100 µGy/min.

Conclusions: The new Esteya(®) Electronic Brachytherapy System presents excellent flatness and penumbra as with the Valencia applicator case, combined with an improved PDD, allowing treatment of lesions of up to a depth of 5 mm in combination with reduced treatment duration. The Esteya unit allows HDR brachytherapy superficial treatment within a minimally shielded environment due its low energy.

Keywords: electronic brachytherapy; nonmelanoma skin-cancer; skin brachytherapy; superficial radiotherapy.

Figures

Fig. 1
Fig. 1
The Esteya Electronic Brachytherapy System
Fig. 2
Fig. 2
Schematic view of the spectrum measurement setup
Fig. 3
Fig. 3
Schematic representation of the setup for the leakage evaluation
Fig. 4
Fig. 4
Esteya electronic brachytherapy system spectrum
Fig. 5
Fig. 5
30 mm applicator central axis depth dose normalized @ 3 mm
Fig. 6
Fig. 6
Half profiles at 5 mm depth normalized to the central axis value for the 30 mm in diameter applicators

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References

    1. Guix B, Finestres F, Tello J, et al. Treatment of skin carcinomas of the face by high-dose-rate brachytherapy and custom-made surface molds. Int J Rad Onc Biol Phys. 2000;47:95–102. - PubMed
    1. Granero D, Perez-Calatayud J, Gimeno J, et al. Design and evaluation of a HDR skin applicator with flattening filter. Med Phys. 2008;35:495–503. - PubMed
    1. Perez-Calatayud J, Granero D, Ballester F, et al. A dosimetric study of Leipzig applicators. Int J Rad Onc Biol Phys. 2005;62:579–584. - PubMed
    1. Niu H, Hsi WC, Chu JC, et al. Dosimetric characteristics of the Leipzig surface applicators used in the high dose rate brachy radiotherapy. Med Phys. 2004;31:3372–3377. - PubMed
    1. Evans MD, Yassa M, Podgorsak EB, et al. Surface applicators for high dose rate brachytherapy in AIDS-related Kaposi's sarcoma. Int J Rad Onc Biol Phys. 1997;39:769–774. - PubMed

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