Garcia-Martinez Teresa, Chan Jan-Pieter, Perez-Calatayud Jose, Ballester Facundo
Department of Radiation Oncology, La Fe University and Polytechnic Hospital, Valencia, Spain.
PANalytical B.V., Eindhoven, the Netherlands.
J Contemp Brachytherapy. 2014 Mar;6(1):45-53. doi: 10.5114/jcb.2014.40770. Epub 2014 Feb 19.
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.
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).
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.
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.
使用表面敷贴器，即莱比锡型或巴伦西亚型，将放射性高剂量率（HDR）（192）铱源近距离放射治疗应用于小皮肤癌病变。皮肤癌放射治疗领域的新进展包括电子近距离放射治疗。该技术涉及将HDR X射线源放置在靠近皮肤的位置，因此将近距离放射治疗的优点与减少的屏蔽要求以及低能X射线的靶向能量相结合。最近，Esteya（®）电子近距离放射治疗系统（Esteya EBS，医科达公司 - 核通，瑞典斯德哥尔摩）已专门开发用于表面病变的HDR近距离放射治疗。该系统通过一个小型69.5 kV X射线源提供无放射性核素的HDR近距离放射治疗。本研究的目的是获得临床实施所需的剂量学特征，提供进行调试的详细方法。
对一组敷贴器（直径从10毫米到30毫米）的平坦度、对称性和半值层、深度剂量百分比（PDD）、千伏稳定性、半价层（HVL）、输出、能谱、线性度和泄漏进行了评估。
平坦度和对称性优于5%，半值层约为1毫米。深度剂量梯度约为7%/毫米。获得的千伏值为68.4±1.0 kV（k = 1），与制造商数据（69.5 kV）高度一致。半价层为1.85毫米铝。典型的6 Gy至7 Gy处方的剂量率约为3.3 Gy/分钟，泄漏值<100μGy/分钟。
新型Esteya（®）电子近距离放射治疗系统与巴伦西亚敷贴器情况一样，具有出色的平坦度和半值层，同时改善了深度剂量百分比，允许治疗深度达5毫米的病变，并缩短治疗时间。由于其低能量，Esteya装置允许在最小屏蔽环境内进行HDR近距离放射治疗浅表治疗。
