Dosimetry on transverse axes of 125I and 192Ir interstitial brachytherapy sources.
Dosimetry on transverse axes of 125I and 192Ir interstitial brachytherapy sources.
复制标题
125I 和 192Ir 间质近距离放射治疗源横轴剂量测定。
DOI：
10.1118/1.596584
复制
发表时间：
1990
期刊：
影响因子：
3.8
通讯作者：
Meli,JA
中科院分区：
文献类型：
--
作者：
Nath,R;Meigooni,AS;Meli,JA
使用LiF热释光剂量计（TLD），在固体水体模中测量了用于组织间近距离放射治疗的125 I型号6702、125 I型号6711和192 Ir 0.2-mm钢源的沿着横轴的剂量率，测量距离达10 cm。125 I 6702型、125 I 6711型和192 Ir 0.2 mm钢源的比剂量率常数（沿源垂直平分线沿着1 cm每单位源强度在水中的剂量率）分别为0.90±0.03、0.85±0.03和1.09±0.03 cGy h− 1 U − 1，分别（1 U=空气比释动能强度单位=1 μ戈伊m2 h-1=1 c戈伊cm 2 h-1）。在旧的和过时的源强度单位（即，mCi表观），分别为1.14±0.03、1.08±0.03和4.59±0.15 cGy h− 1 mCi −1（表观）。目前公认的125 I源的比剂量率常数值比我们的测量值高出20%，这与我们的Monte Carlo模拟结果很好地吻合。但对于192 Ir，我们的比剂量率常数的测量值与目前公认的值之间有很好的一致性。发现125 I模型6702的径向剂量函数始终大于125 I模型6711的径向剂量函数，并且随着与源的距离增加，差异增大。我们对125 I源的径向剂量函数的测量值与我们的MonteCarlo模拟结果以及Schelletal的测量值符合得很好。[Int. J. Radiat. Oncol. Biol.Phys.13，795-799（1987）]。[Int. J. Radiat. Oncol. Biol.Phys.9，1747-1752（1983）]。然而，一些最近报道的蒙特卡罗值的径向剂量函数for 125 I源显着大于测量值，高达18%，在5厘米的距离。我们测量的径向剂量函数的192 Ir种子是在很好的协议与我们的Monte Carlo计算值，并与我们的早期数据的高活性192 Ir源的远程后装机和建议值Meisbergeretal。[Radiol.90，953-957（1968）]。
Dose rates along the transverse axes of125I model 6702,125I model 6711 and192Ir 0.2‐mm steel sources for interstitial brachytherapy have been measured in a solid‐water phantom for distances up to 10 cm using LiF thermoluminescent dosimeters (TLDs). Specific dose rate constants, the dose rates in water per unit source strength 1 cm along the perpendicular bisector of the source, are determined to be 0.90±0.03, 0.85±0.03, and 1.09±0.03 cGy h−1U−1for125I model 6702,125I model 6711 and192Ir 0.2‐mm steel sources, respectively (1 U=unit of air kerma strength =1 μGy m2h−1=1 cGy cm2h−1). In older and obsolete units of source strength (i.e., mCi apparent), these are 1.14±0.03, 1.08±0.03, and 4.59±0.15 cGy h−1mCi−1(apparent). Currently accepted values of specific dose rate constant for125I sources are up to 20% higher than our measured values which are in good agreement with the results of our Monte Carlo simulations. But for192Ir there is good agreement between our measured value of the specific dose rate constant and currently accepted values. The radial dose function for125I model 6702 is found to be consistently larger than that for125I model 6711, with an increasing difference as the distance from the source increases. Our measured values for the radial dose function for125I sources are in good agreement with the results of our Monte Carlo simulation as well as the measured values of Schelletal. [Int. J. Radiat. Oncol. Biol. Phys.13, 795–799 (1987)] for model 6702 and Lingetal. [Int. J. Radiat. Oncol. Biol. Phys.9, 1747–1752 (1983)] for model 6711. However, some of the recently reported Monte Carlo values of the radial dose function for125I sources are significantly larger than measured values; up to 18% at a distance of 5 cm. Our measured radial dose function for the192Ir seed is in good agreement with our Monte Carlo calculated values, and with both our earlier data for the high activity192Ir source of a remote afterloader and recommended values by Meisbergeretal. [Radiol.90, 953–957 (1968)].