Nickers P, Coppens L, Beauduin M, Sabatier J, Albert A, de Leval J, Deneufbourg J M
Radiation Oncology Department, University Hospital, Liège, Belgium.
Strahlenther Onkol. 2001 Feb;177(2):90-5. doi: 10.1007/pl00002389.
Increasing the dose to prostatic adenocarcinoma in conformal external beam therapy (EBT) has resulted in increased levels of PSA normalization and increased percentage of biochemical disease-free survival rates. However technical problems due to prostate motion inside the pelvis or patients' set-up make difficult the realization of the EBT boost fields above 72 Gy. Brachytherapy which overcomes these problems was investigated to deliver the boost dose to achieve 85 Gy. PSA nadir which has been identified as the strongest independent predictor of any failure in many studies has been used as the end point for early evaluation of this work.
In a retrospective way we report on 163 patients' PSA kinetics after EBT alone to 68 Gy or EBT first and a brachytherapy boost up to 75 or 85 Gy.
At 12 months follow-up, PSA nadirs percentage < or = 0.5 or < or = 1 ng/ml increased from 7.5 and 20.7% after 68 Gy EBT to 49.8 and 71.2% after a brachytherapy boost to deliver 85 Gy (p < 0.0001). In the Cox PH model analysis, the total dose remained the most important factor for predicting PSA normalization.
These results are in accordance with the most recent results published after conformal EBT at the same 80 Gy level of dose. If confirmed on a higher number of patients they could place brachytherapy among the most accurate methods of boosting in the radiation treatment of prostatic carcinoma.
在适形外照射治疗（EBT）中增加前列腺癌的剂量已使前列腺特异性抗原（PSA）正常化水平提高，生化无病生存率百分比增加。然而，由于骨盆内前列腺运动或患者摆位导致的技术问题，使得实现高于72 Gy的EBT加量野变得困难。为了给予85 Gy的加量剂量，对克服这些问题的近距离放射治疗进行了研究。在许多研究中，PSA最低点已被确定为任何失败的最强独立预测因子，它已被用作这项工作早期评估的终点。
我们以回顾性方式报告了163例患者在单独接受68 Gy EBT或先接受EBT然后接受近距离放射治疗加量至75或85 Gy后的PSA动力学情况。
在12个月的随访中，PSA最低点≤0.5或≤1 ng/ml的百分比从68 Gy EBT后的7.5%和20.7%增加到近距离放射治疗加量至85 Gy后的49.8%和71.2%（p<0.0001）。在Cox比例风险模型分析中，总剂量仍然是预测PSA正常化的最重要因素。
这些结果与在相同80 Gy剂量水平的适形EBT后发表的最新结果一致。如果在更多患者中得到证实，它们可能会使近距离放射治疗成为前列腺癌放射治疗中最精确的加量方法之一。
