Crook J, Lukka H, Klotz L, Bestic N, Johnston M
Princess Margaret Hospital, Toronto, Ont.
CMAJ. 2001 Apr 3;164(7):975-81.
Brachytherapy (permanent implantation of radioactive seeds) has emerged as an alternative to existing standard therapy with radical prostatectomy or external beam radiotherapy in the treatment of clinically localized (T1 and T2) prostate cancer. The Genitourinary Cancer Disease Site Group of the Cancer Care Ontario Practice Guidelines Initiative examined the role of brachytherapy in treating clinically localized prostate cancer.
A systematic review of articles published from 1988 to April 1999, retrieved through a search of MEDLINE and CANCERLIT databases, was combined with a consensus interpretation of the evidence in the context of conventional practice.
Although there were no randomized trials comparing brachytherapy with standard treatment, evidence was available from 13 case series and 3 cohort studies. Rates of freedom from biochemical failure (biochemically no evidence of disease [bNED]) varied considerably from one series to another and were highly dependent on tumour stage, grade and pretreatment serum prostate-specific antigen (PSA) levels. Results in patients with favourable tumours (T1 or T2 tumour, Gleason score of 6 or lower, serum PSA level of 10 ng/mL [microgram/L] or less) were comparable to those in patients undergoing radical prostatectomy. Acute urinary retention was reported in 1%-14% of patients. Long-term sequelae occurred in less than 5% of patients and included urinary incontinence, cystitis, urethral strictures and proctitis. Sexual potency was maintained after implantation in 86%-96% of patients.
At present, there is insufficient evidence to recommend the use of brachytherapy over current standard therapy for localized prostate cancer. Brachytherapy using transrectal ultrasound guidance for seed implantation is promising in terms of freedom from biochemical failure in selected patients with early-stage prostate cancer. Brachytherapy is currently available outside of clinical trials, but whenever possible patients should be asked to participate in randomized trials comparing brachytherapy and current standard therapy. Brachytherapy should be available to selected patients (those with T1c or T2a tumours, a Gleason score of 6 or lower and a serum PSA level of 10 micrograms/L or less), after discussion of the available data and potential adverse effects.
近距离放射疗法（放射性粒子永久植入）已成为治疗临床局限性（T1和T2期）前列腺癌的一种替代现有标准疗法（根治性前列腺切除术或外照射放疗）的方法。安大略癌症护理实践指南倡议组织的泌尿生殖系统癌症疾病部位小组研究了近距离放射疗法在治疗临床局限性前列腺癌中的作用。
通过检索MEDLINE和CANCERLIT数据库，对1988年至1999年4月发表的文章进行系统回顾，并结合在传统实践背景下对证据的共识解读。
虽然没有将近距离放射疗法与标准治疗进行比较的随机试验，但有来自13个病例系列和3个队列研究的证据。生化无进展率（生化检查无疾病证据[bNED]）在不同系列之间差异很大，并且高度依赖于肿瘤分期、分级和治疗前血清前列腺特异性抗原（PSA）水平。肿瘤情况良好（T1或T2期肿瘤、Gleason评分6分或更低、血清PSA水平10 ng/mL[微克/升]或更低）的患者的结果与接受根治性前列腺切除术的患者相当。1%-14%的患者报告发生急性尿潴留。不到5%的患者出现长期后遗症，包括尿失禁、膀胱炎、尿道狭窄和直肠炎。86%-96%的患者植入后性功能得以维持。
目前，没有足够的证据推荐使用近距离放射疗法而非当前的局限性前列腺癌标准疗法。对于选定的早期前列腺癌患者，经直肠超声引导下进行粒子植入的近距离放射疗法在生化无进展方面很有前景。近距离放射疗法目前在临床试验之外也可应用，但只要有可能，应要求患者参与比较近距离放射疗法和当前标准疗法的随机试验。在讨论现有数据和潜在不良反应后，应向选定的患者（T1c或T2a期肿瘤、Gleason评分6分或更低且血清PSA水平10微克/升或更低的患者）提供近距离放射疗法。
