Valicenti R K, Gomella L G, Ismail M, Mulholland S G, Petersen R O, Corn B W
Department of Radiation Oncology, Jefferson Medical College and Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107, USA.
Int J Radiat Oncol Biol Phys. 1998 Oct 1;42(3):501-6. doi: 10.1016/s0360-3016(98)00270-3.
The appropriate radiation dose has not been determined for postoperative radiation therapy (RT) of prostate cancer. Postoperative PSA level is a useful marker of local residual disease, and may allow evaluation of RT dose-response after radical prostatectomy.
Between 1989 and 1996, 86 consecutive patients with pT3N0 prostate cancer who did not receive prior hormonal therapy or chemotherapy were irradiated postoperatively. All patients received 55.8 to 70.2 Gy (median = 64.8 Gy) to the prostatic/seminal vesicle bed. Patients were judged to be free of biochemical failure (bNED) if their PSA remained undetectable or decreased to undetectable level (< 0.2 ng/ml). The median follow-up time was 32 months from time of irradiation.
Univariate and multivariate analyses of variables showed that the preRT PSA level was the most significant predictor of improved bNED survival (p < 0.001). Actuarial analyses of radiation dose grouped with preRT PSA levels found higher radiation dose to be significant (p < 0.05). For the 52 patients with an undetectable preRT PSA level, the 3-year bNED rate was 91% for patients irradiated to 61.5 Gy or more and 57% for those irradiated to lower doses (p = 0.01). For the 21 patients with preRT PSA level > 0.2 and < or = 2.0 ng/ml, the 3-year bNED rate was 79% for patients irradiated to 64.8 Gy or more and 33% for those irradiated to a lower dose (p = 0.02). No other preRT PSA interval or radiation dose level was associated with a dose-response function.
In patients with pT3N0 prostate cancer after radical prostatectomy, a radiation dose-response function may be present and depends on the preRT PSA value. Patients with high postoperative PSA levels (> 2.0 ng/ml) may be less likely to benefit from higher doses of RT, and should be considered a group for which systemic therapy should be tested.
前列腺癌术后放射治疗（RT）的合适辐射剂量尚未确定。术后前列腺特异抗原（PSA）水平是局部残留疾病的一个有用标志物，并且可能有助于评估根治性前列腺切除术后放疗的剂量反应。
1989年至1996年间，86例连续的pT3N0前列腺癌患者在术后接受放疗，这些患者未接受过先前的激素治疗或化疗。所有患者均接受55.8至70.2 Gy（中位数 = 64.8 Gy）的前列腺/精囊床照射。如果患者的PSA仍无法检测到或降至无法检测水平（< 0.2 ng/ml），则判定为无生化失败（bNED）。从放疗时间起，中位随访时间为32个月。
变量的单因素和多因素分析表明，放疗前PSA水平是改善bNED生存率的最显著预测因素（p < 0.001）。对与放疗前PSA水平分组的辐射剂量进行精算分析发现，较高的辐射剂量具有显著性（p < 0.05）。对于52例放疗前PSA水平无法检测到的患者，接受61.5 Gy或更高剂量照射的患者3年bNED率为91%，而接受较低剂量照射的患者为57%（p = 0.01）。对于21例放疗前PSA水平> 0.2且≤ 2.0 ng/ml的患者，接受64.8 Gy或更高剂量照射的患者3年bNED率为79%，而接受较低剂量照射的患者为33%（p = 0.02）。没有其他放疗前PSA区间或辐射剂量水平与剂量反应函数相关。
在根治性前列腺切除术后的pT3N0前列腺癌患者中，可能存在辐射剂量反应函数，且取决于放疗前PSA值。术后PSA水平高（> 2.0 ng/ml）的患者可能不太可能从更高剂量的放疗中获益，应被视为一个可进行全身治疗试验的群体。
