巴巴原子研究中心OcuProsta I-125种子源的剂量测定参数。

Dosimetry parameters of BARC OcuProsta I-125 seed source.

作者信息

Sharma S D, Basu M, Shanta A, Selvam T Palani, Tripathi U B, Bhatt B C

机构信息

Radiological Physics & Advisory Division, Bhabha Atomic Research Centre, Mumbai, India.

出版信息

Australas Phys Eng Sci Med. 2005 Mar;28(1):14-20. doi: 10.1007/BF03178859.

DOI:10.1007/BF03178859

PMID:15920985

Abstract

A new model of 125I seed source, named OcuProsta seed, was designed and fabricated by Radiopharmaceuticals Division of Bhabha Atomic Research Centre for ophthalmic and interstitial applications. AAPM TG 43 recommended dosimetry parameters for this seed source were determined experimentally using TLD as well as by Monte Carlo (MC) simulation. Measured and MC calculated values of the dose rate constant (DRC) are 0.95 +/- 0.065 cGyh(-1)U(-1) and 0.972 +/- 0.005 cGyh(-1)U(-1), respectively. The mean of measured and calculated DRC (lambda = 0.96 cGyh(-1)U(-1)) was recommended for the clinical dosimetry of OcuProsta seed. Measured and MC calculated radial dose function, g(r), anisotropy function, F(r,theta), anisotropy factor and anisotropy constants are also found to be in good agreement to each other. Dosimetry parameters of OcuProsta seed were compared with the published values of similar in-design 125I seed sources. The DRC of BARC OcuProsta seed is very close to Amersham 6711 seed and is also comparable to the DRC of Best model 2301, Syncor PharmaSeed and Isotron selectSeed within the uncertainty of measurement/calculation. The g(r) of OcuProsta seed shows a difference of up to 10% in comparison to the g(r) values of the similar in-design seed sources. The values of anisotropy function of OcuProsta are 7-13% different from the anisotropy function of Amersham 6711 and Syncor PharmaSeed. The anisotropy constant of OcuProsta is close to Amersham 6711 seed while it is about 9% smaller than the anisotropy constant of Best model 2301 and Synchor PharmaSeed.

摘要

巴巴原子研究中心放射性药物分部设计并制造了一种名为OcuProsta种子的新型125I种子源，用于眼科和间质应用。使用热释光剂量计（TLD）以及蒙特卡罗（MC）模拟实验确定了AAPM TG 43推荐的该种子源剂量学参数。剂量率常数（DRC）的测量值和MC计算值分别为0.95±0.065 cGy h-1U-1和0.972±0.005 cGy h-1U-1。建议将测量值和计算值的DRC平均值（λ = 0.96 cGy h-1U-1）用于OcuProsta种子的临床剂量学。还发现测量的和MC计算的径向剂量函数g(r)、各向异性函数F(r,θ)、各向异性因子和各向异性常数彼此之间非常吻合。将OcuProsta种子的剂量学参数与设计类似的125I种子源的已发表值进行了比较。BARC OcuProsta种子的DRC非常接近Amersham 6711种子，并且在测量/计算的不确定度范围内也与Best model 2301、Syncor PharmaSeed和Isotron selectSeed的DRC相当。与设计类似的种子源的g(r)值相比，OcuProsta种子的g(r)显示出高达10%的差异。OcuProsta的各向异性函数值与Amersham 6711和Syncor PharmaSeed的各向异性函数值相差7%-13%。OcuProsta的各向异性常数接近Amersham 6711种子，而比Best model 2301和Synchor PharmaSeed的各向异性常数小约9%。