Shah Jinesh N, Wuu Cheng-Shie, Katz Aaron E, Laguna Joseph L, Benson Mitchell C, Ennis Ronald D
Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, New York, New York 10019, USA.
Cancer J. 2006 Jul-Aug;12(4):289-97. doi: 10.1097/00130404-200607000-00007.
We hypothesized that intraoperative preplanning for transperineal interstitial permanent prostate brachytherapy may yield better prostate cancer control than preoperative preplanning. We tested this hypothesis by comparing treatment outcomes of patients who underwent implantation using these two preplanning methods.
We analyzed the data of 135 consecutive patients with localized prostate cancer treated from 1996 to 2001 with transperineal interstitial permanent prostate brachytherapy+/-preimplantation hormonal therapy: 42 received preoperative preplanning (group 1), and 93 underwent intraoperative preplanning (group 2). Biochemical status was assessed using two failure definitions: American Society for Therapeutic Radiology and Oncology (ASTRO) (three consecutive rises in prostate-specific antigen level) and Houston (prostate-specific antigen level>or=current nadir+2 ng/mL). Clinical disease-free survival and postimplantation dosimetry were also examined.
All disease control outcomes were superior for group 2. The 4-year ASTRO biochemical no evidence of disease rate was 80% for group 1 versus 94% for group 2. The 4-year Houston biochemical no evidence of disease rate was 82% for group 1 versus 96% for group 2. The 4-year clinical disease-free survival rate was 87% for group 1 versus 99% for group 2. Preplanning method (preoperative versus intraoperative) remained predictive of disease control outcomes in multivariate analyses with the covariates of pretreatment prostate-specific antigen level, Gleason score, clinical stage, and case sequence number (proxy for brachytherapist experience and "stage migration"). Dosimetric prostate coverage was superior for group 2. The mean percentage of the prescription dose delivered to 90% of the prostate volume (%D90) was 75% for group 1 versus 90% for group 2. A %D90>or=70% predicted for improved disease control; fewer group 1 than 2 patients met this dosimetric criterion (55% versus 87%).
Intraoperative preplanning yielded superior disease control outcomes in this analysis, likely due at least in part to improved dosimetric prostate coverage with this method. Although not mandatory for obtaining high prostate brachytherapy efficacy, intraoperative preplanning nevertheless may offer an excellent means of improving dosimetric prostate coverage and therefore disease control outcomes.
我们推测，与术前预规划相比，经会阴间质永久性前列腺近距离放射治疗术中预规划可能会更好地控制前列腺癌。我们通过比较采用这两种预规划方法进行植入的患者的治疗结果来验证这一假设。
我们分析了1996年至2001年接受经会阴间质永久性前列腺近距离放射治疗±植入前激素治疗的135例连续性局限性前列腺癌患者的数据：42例接受术前预规划（第1组），93例接受术中预规划（第2组）。使用两种失败定义评估生化状态：美国放射肿瘤学会（ASTRO）（前列腺特异性抗原水平连续三次升高）和休斯顿标准（前列腺特异性抗原水平≥当前最低点+2 ng/mL）。还检查了临床无病生存率和植入后剂量测定。
第2组的所有疾病控制结果均更优。第1组4年的ASTRO生化无疾病证据率为80%，而第2组为94%。第1组4年的休斯顿生化无疾病证据率为82%，而第2组为96%。第1组4年的临床无病生存率为87%，而第2组为99%。在多变量分析中，预规划方法（术前与术中）仍然是疾病控制结果的预测因素，协变量包括治疗前前列腺特异性抗原水平、 Gleason评分、临床分期和病例序号（代表近距离放射治疗师经验和“分期迁移”）。第2组的剂量学前列腺覆盖更好。第1组输送至90%前列腺体积的处方剂量平均百分比（%D90）为75%，而第2组为90%。%D90≥70%预示疾病控制改善；达到该剂量学标准的第1组患者少于第2组患者（55%对87%）。
在本分析中，术中预规划产生了更好的疾病控制结果，这可能至少部分归因于该方法改善了剂量学前列腺覆盖。尽管术中预规划并非获得高前列腺近距离放射治疗疗效的必要条件，但它仍然可能是改善剂量学前列腺覆盖从而改善疾病控制结果的一种极佳方法。
