D'Amico A V, Coleman C N
Joint Center for Radiation Therapy, Harvard Medical School, Boston, MA, USA.
J Clin Oncol. 1996 Jan;14(1):304-15. doi: 10.1200/JCO.1996.14.1.304.
To discuss the evolution of the use of brachytherapy in the treatment of clinically organ-confined prostate cancer and to review modern techniques, results of therapy, and optimal patient selection criteria.
Using modern localization and immobilization techniques, interstitial prostate radiotherapy for patients with a prostate-specific antigen (PSA) level less than 10 ng/mL yields an at least 87% rate of freedom from biochemical relapse at 3 years, which is numerically equivalent to results achieved with external-beam radiotherapy or radical prostatectomy. With a minimum median follow-up time of 24 months, 81% to 85% (2-year actuarial and 3-year crude) potency rates have been reported concomitant with 2-year actuarial rates of 12% for grade > or = 2 rectal complications and 10% for grade > or = 3 urethral complications.
The combination of clinical stage, PSA level, and biopsy Gleason sum allows for selection of patients with the highest probability of having all of the prostate cancer encompassed by the high-dose implant volume, while simultaneously respecting the normal-tissue tolerance doses of the juxtaposed normal tissues (rectum and bladder). In particular, patients with nonpalpable (T1c) lesions, a biopsy Gleason sum < or = 6 (ideally < or = 4), and a PSA level less than 10 ng/mL represent the optimal implant candidates. Differential loading of the implant away from the geometric center and not accepting patients with large prostate glands (> or = 60 cm3) or history of a transurethral resection of the prostate (TURP) as implant candidates, may reduce urethral toxicity. Further follow-up evaluation of prostate cancer patients treated with interstitial radiotherapy will verify if favorable potency preservation rates and rates of freedom from biochemical failure equivalent to those achieved with radical prostatectomy or external-beam radiation therapy are maintained.
探讨近距离放射疗法在临床局限于器官的前列腺癌治疗中的应用演变,并回顾现代技术、治疗结果及最佳患者选择标准。
采用现代定位和固定技术,对前列腺特异性抗原(PSA)水平低于10 ng/mL的患者进行间质前列腺放疗,3年时生化复发-free率至少为87%,在数值上等同于外照射放疗或根治性前列腺切除术的结果。在最短中位随访时间为24个月的情况下,报告的性功能保留率为81%至85%(2年精算和3年粗率),同时2级及以上直肠并发症的2年精算发生率为12%,3级及以上尿道并发症的发生率为10%。
临床分期、PSA水平和活检Gleason总分相结合,有助于选择那些高剂量植入体积能够覆盖所有前列腺癌且同时符合相邻正常组织(直肠和膀胱)正常组织耐受剂量的患者。特别是,不可触及(T1c)病变、活检Gleason总分≤6(理想情况下≤4)且PSA水平低于10 ng/mL的患者是最佳的植入候选者。将植入物的剂量加载远离几何中心,不接受前列腺体积大(≥60 cm³)或有经尿道前列腺切除术(TURP)病史的患者作为植入候选者,可能会降低尿道毒性。对接受间质放疗的前列腺癌患者进行进一步的随访评估,将验证是否能维持与根治性前列腺切除术或外照射放疗相当的良好性功能保留率和生化无失败率。