Department of Radiation Oncology, University of Pittsburgh Cancer Institute, UPMC Cancer Centers, Pittsburgh, PA 15232, USA.
J Appl Clin Med Phys. 2013 Jan 7;14(1):3862. doi: 10.1120/jacmp.v14i1.3862.
The study is designed to investigate the effect of edema on the delivered dose, tumor cell surviving fraction (SF), and tumor control probability (TCP) in the patients of prostate cancer who underwent (131)Cs permanent seed implantation. The dose reduction, the SF, and the TCP for edematous prostate implants were calculated for 31 patients who underwent real-time (131)Cs permanent seed implantation for edema half-lives (EHL), ranging from 4 days to 34 days and for edema magnitudes (M0) varying from 5% to 60% of the actual prostate volume. A dose reduction in (131)Cs implants varied from 1.1% (for EHL = 4 days and M(0) = 5%) to 32.3% (for EHL = 34 days and M(0) = 60%). These are higher than the dose reduction in 125I implants, which vary from 0.3% (for EHL = 4 days and M(0) = 5%) to 17.5% (for EHL = 34 days and M(0) = 60%). As EHL increased from 4 days to 34 days and edema magnitude increased from 5% to 60%, the natural logarithmic value of SF increased by 4.57 and the TCP decreased by 0.80. Edema induced increase in the SF and decrease in the TCP in (131)Cs seed implants, is significantly more pronounced in a combination of higher edema magnitude and larger edema half-lives than for less edema magnitude and lower edema half-lives, as compared for M(0) = 60% and EHL = 34, and M(0) = 5% and EHL = 4 days.
本研究旨在探讨前列腺癌患者接受（131）Cs 永久性种子植入术后水肿对放射性剂量、肿瘤细胞存活分数（SF）和肿瘤控制概率（TCP）的影响。对于接受实时（131）Cs 永久性种子植入术的 31 例水肿半衰期（EHL）为 4 天至 34 天、水肿幅度（M0）为实际前列腺体积的 5%至 60%的患者，计算了放射性剂量减少、SF 和 TCP。（131）Cs 植入物的放射性剂量减少幅度从 EHL = 4 天和 M0 = 5%时的 1.1%（1.1%）到 EHL = 34 天和 M0 = 60%时的 32.3%。这些剂量减少幅度高于 125I 植入物的剂量减少幅度，从 EHL = 4 天和 M0 = 5%时的 0.3%（0.3%）到 EHL = 34 天和 M0 = 60%时的 17.5%。随着 EHL 从 4 天增加到 34 天，水肿幅度从 5%增加到 60%，SF 的自然对数增加了 4.57，TCP 减少了 0.80。与水肿幅度和水肿半衰期较小的情况相比，（131）Cs 种子植入物中水肿引起的 SF 增加和 TCP 降低在较高的水肿幅度和较大的水肿半衰期组合中更为显著，与 M0 = 60%和 EHL = 34 相比，以及 M0 = 5%和 EHL = 4 天。
