Tel Aviv University, Tel Aviv Israel Center for Disease Control, Sheba Medical Center, Tel Hashomer, Israel.
BJU Int. 2012 Jun;109(11):1661-5. doi: 10.1111/j.1464-410X.2011.10748.x. Epub 2011 Nov 24.
Study Type - Prognostic (cohort) Level of Evidence 2b What's known on the subject? and What does the study add? Nomograms are based on large patient population. Their applicability should be externally validated. Among 747 brachytherapy patients we evaluated two Kattan nonograms and conclude that they have limited value to predict PSA-free survival.
To validate and compare the preoperative and postoperative Kattan prediction nonograms for prostate cancer recurrence after brachytherapy.
Patients (n= 747) treated with (125) I-brachytherapy were evaluated. Both nomograms were used to calculate the prediction of 5-year biochemical-freedom from failure (BFFF) based on clinical stage, Gleason score, prostate-specific antigen (PSA) level, receipt of androgen deprivation therapy and the post-implant dosimetry variable D90 (values of the minimal dose received by 90% of the prostate volume). The predicted values using the Kattan nomograms and the observed values were compared. Predictive accuracy was determined using the concordance index.
The 5-year BFFF probability was 94% (95% confidence interval [CI], 92-96%) for the modified American Society for Radiation Oncology (ASTRO) definition and 97% (95% CI, 95-98%) for the Phoenix definition using Kaplan-Meier analysis. The predicted values of BFFF using both Kattan nomograms were lower than the observed rates in our cohort. The concordance index values were 0.51 and 0.52 for preoperative and postoperative nomograms, respectively. Concordance correlation coefficient between the two nomograms was 0.15.
In our population, the 5-year BFFF outcomes rates were superior to nomogram predictions. Neither nomogram predicted outcomes after (125) I-brachytherapy in this non-US cohort. The postoperative nomogram was also a poor predictor, although it included D90 dosimetry values, as a variable of treatment quality. Strict inclusion criteria, perhaps more favourable than the ones on which the Kattan nomograms were based, could be the explanation for these discrepancies.
研究类型-预后（队列）证据水平 2b 本领域已知内容：诺模图基于大量患者群体。其适用性应经过外部验证。在 747 例近距离放射治疗患者中，我们评估了两种 Kattan 非诺图，并得出结论，它们对预测 PSA 无复发生存率的价值有限。
验证和比较术前和术后 Kattan 预测前列腺癌近距离放射治疗后复发的非诺图。
评估了 747 例接受（125）I-近距离放射治疗的患者。基于临床分期、Gleason 评分、前列腺特异性抗原（PSA）水平、雄激素剥夺治疗的接受情况以及植入后剂量学变量 D90（前列腺体积 90%接受的最小剂量值），使用两种诺模图计算 5 年生化无失败（BFFF）预测值。比较 Kattan 诺模图预测值和观察值。使用一致性指数确定预测准确性。
Kaplan-Meier 分析显示，使用改良美国放射肿瘤学会（ASTRO）定义的 5 年 BFFF 概率为 94%（95%置信区间[CI]，92-96%），使用凤凰定义的概率为 97%（95%CI，95-98%）。在我们的队列中，使用两种 Kattan 诺模图预测的 BFFF 概率均低于观察值。术前和术后诺模图的一致性指数值分别为 0.51 和 0.52。两个诺模图之间的一致性相关系数为 0.15。
在我们的人群中，5 年 BFFF 结果率优于诺模图预测。这两个非美国队列的诺模图均不能预测（125）I-近距离放射治疗后的结果。尽管术后诺模图包含了作为治疗质量变量的 D90 剂量学值，但也是一个较差的预测因子。出现这些差异的原因可能是纳入标准更严格，或许比 Kattan 诺模图的纳入标准更有利。
