Dosimetric consequences of using a surrogate urethra to estimate urethral dose after brachytherapy for prostate cancer
Dosimetric consequences of using a surrogate urethra to estimate urethral dose after brachytherapy for prostate cancer
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DOI：
10.1016/s0360-3016(03)00583-2
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发表时间：
2003-10-01
影响因子：
7
通讯作者：
Kuban, DA
中科院分区：
文献类型：
--
作者：
Lee, HK;D'Souza, WD;Kuban, DA
目的：为了评估的准确性和剂量测定的后果，定义一个替代尿道的几何中心的前列腺在postimplant CT scannes.Methods和材料：80 postimplant CT扫描获得了一个Foley导管到位在0天，并在1个月的40例患者谁经历了I-125前列腺近距离放射治疗。测量Foley导尿管和替代尿道接受至少275%处方剂量的尿道体积百分比（uV（275））、uV（250）、uV（200）、uV（150）、90%尿道体积接受的最大剂量（uD（90））、uD（70）、uD（30）和uD（1）。Foley导管和替代尿道之间的距离进行了测量，在基地，中间，和apex的prostates.Results：一个统计学上的显着差异被发现在所有上述列出的剂量测定参数之间的Foley导管和替代尿道在第0天（p小于或等于0.001）。1个月时，导尿管和替代尿道之间的uD（90）、uD（70）和uD（1）仍存在显著差异（p ≤ 0.05）。1个月时，Foley导管和替代尿道之间的uV 275（p = 0.055）和uV（150）（p = 0.059）差异显示出统计学显著性趋势。1个月时，替代尿道的uV（250）、uV（200）和uD（30）大于Foley导管，但在统计学上无显著差异。Foley导管和替代尿道之间的平均距离是最大的基地（1.2厘米）在垂直轴在第0天，并大幅下降至0.87厘米，在1个月（p = 0.0004）。结论：使用替代尿道的几何中心的前列腺可能会显着高估尿道剂量在第0天和某些剂量测定参数在1个月。在未来的研究中，可以考虑替代尿道的替代位置，以解释第0天和第1个月时前列腺基底附近Foley导管位置的差异。(C)2003爱思唯尔公司
Purpose: To assess the accuracy and dosimetric consequences of defining a surrogate urethra at the geometric center of the prostate in postimplant CT scans.Methods and Materials: Eighty postimplant CT scans were obtained with a Foley catheter in place at Day 0 and at 1 month for 40 patients who had undergone I-125 prostate brachytherapy. The percentage of urethral volume receiving at least 275% of the prescribed dose (uV(275)), uV(250), uV(200), uV(150), maximal dose received by 90% of urethral volume (uD(90)), uD(70), uD(30), and uD(1) were measured for the Foley catheter and surrogate urethra. The distance between the Foley catheter and surrogate urethra was measured at the base, middle, and apex of the prostate.Results: A statistically significant difference was found in all the above-listed dosimetric parameters between the Foley catheter and surrogate urethra at Day 0 (p less than or equal to 0.001). At 1 month, the uD(90), uD(70), and uD(1) remained significantly different between the Foley catheter and surrogate urethra (p less than or equal to 0.05). The difference in the uV275 (p = 0.055) and uV(150) (p = 0.059) between the Foley catheter and surrogate urethra showed a trend toward statistical significance at 1 month. The uV(250), uV(200), and uD(30) were greater for the surrogate urethra than for the Foley catheter at 1 month, but were not significantly different statistically. The mean distance between the Foley catheter and the surrogate urethra was greatest at the base (1.2 cm) in the vertical axis at Day 0 and decreased substantially to 0.87 cm at 1 month (p = 0.0004).Conclusion: Using a surrogate urethra at the geometric center of the prostate may significantly overestimate the urethral dose at Day 0 and certain dosimetric parameters at 1 month. An alternative position for a surrogate urethra accounting for the difference in the location of the Foley catheter near the base of the prostate at Day 0 and 1 month could be considered in future studies. (C) 2003 Elsevier Inc.