Davis B J, Pisansky T M, Wilson T M, Rothenberg H J, Pacelli A, Hillman D W, Sargent D J, Bostwick D G
Division of Radiation Oncology, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
Cancer. 1999 Jun 15;85(12):2630-7.
Extraprostatic extension (EPE) is an unfavorable prognostic factor in patients with prostate carcinoma. Prior studies have reported the linear extent of EPE measured circumferentially along the edge of the prostate. In this study, the authors defined and evaluated a novel measure of EPE in a large series of radical prostatectomy specimens. These results have important clinical implications in the management of localized prostate carcinoma by brachytherapy and other modalities.
The authors reviewed the preoperative records and biopsy findings from 376 patients who underwent radical retropubic prostatectomy between September 1991 and June 1993. Whole mount radical prostatectomy specimens were examined, and the location of EPE for each specimen was recorded. The radial EPE distance was measured perpendicular to the edge of the prostate. For specimens with multiple EPE sites, the maximum radial EPE distance was recorded. Established eligibility criteria for prostate brachytherapy were evaluated using these results, with emphasis placed on achieving adequate radiation dose coverage 3-5 mm beyond the capsule or the edge of the prostate.
EPE was identified in 105 of 376 specimens (28%) at 248 sites. The radial EPE distance in these specimens had a mean of 0.8 mm (range, 0.04-4.4 mm) and a median of 0.5 mm. Of these 105 patients, the median and mean preoperative prostate specific antigen (PSA) concentrations were 11.8 ng/mL and 17.9 ng/mL, respectively. The mean and range of the Gleason score and prostate volume for all specimens were 6.3 (range, 3-9) and 39 cc (range, 8-294 cc), respectively. In 107 patients who met the selection criteria for prostate brachytherapy eligibility of a PSA level < 10 ng/mL, Gleason score < 7, and gland volume < 60 cc, the maximum and mean radial EPE distances were 0.6 mm and 0.03 mm, respectively.
The radial distance of EPE is an important measure that influences treatment strategies for patients with localized prostate carcinoma. Currently described criteria for the treatment of early stage prostate carcinoma by brachytherapy alone appear satisfactory to ensure effective radiation dose coverage of EPE of prostate tumors. Treating the prostate with a 3-5 mm margin by brachytherapy would encompass all known tumor in approximately 99% of the specimens examined in this study.
前列腺外侵犯（EPE）是前列腺癌患者预后不良的一个因素。既往研究报道了沿前列腺边缘周向测量的EPE线性范围。在本研究中，作者定义并评估了一系列根治性前列腺切除标本中EPE的一种新测量方法。这些结果对通过近距离放射治疗和其他方式治疗局限性前列腺癌具有重要的临床意义。
作者回顾了1991年9月至1993年6月间接受耻骨后根治性前列腺切除术的376例患者的术前记录和活检结果。检查了整块根治性前列腺切除标本，并记录每个标本EPE的位置。垂直于前列腺边缘测量径向EPE距离。对于有多个EPE部位的标本，记录最大径向EPE距离。使用这些结果评估已确立的前列腺近距离放射治疗的入选标准，重点是在前列腺包膜或边缘以外3 - 5 mm处实现足够的放射剂量覆盖。
在376例标本中的105例（28%）的248个部位发现了EPE。这些标本的径向EPE距离平均为0.8 mm（范围0.04 - 4.4 mm），中位数为0.5 mm。在这105例患者中，术前前列腺特异性抗原（PSA）浓度的中位数和平均值分别为11.8 ng/mL和17.9 ng/mL。所有标本的Gleason评分平均值和范围分别为6.3（范围为3 - 9）和39 cc（范围为8 - 294 cc）。在107例符合前列腺近距离放射治疗入选标准（PSA水平< 10 ng/mL、Gleason评分< 7且腺体体积< 60 cc）的患者中，最大和平均径向EPE距离分别为0.6 mm和0.03 mm。
EPE的径向距离是影响局限性前列腺癌患者治疗策略的一项重要指标。目前描述的仅通过近距离放射治疗早期前列腺癌的标准似乎足以确保对前列腺肿瘤EPE进行有效的放射剂量覆盖。通过近距离放射治疗以3 - 5 mm的边缘治疗前列腺将涵盖本研究中约99%的检查标本中的所有已知肿瘤。
