Crook Juanita, Gillan Caitlin, Yeung Ivan, Austen Lynette, McLean Michael, Lockwood Gina
Department of Radiation Oncology, University Health Network, Princess Margaret Hospital, Toronto, Ontario, Canada.
Int J Radiat Oncol Biol Phys. 2007 Oct 1;69(2):426-33. doi: 10.1016/j.ijrobp.2007.03.031.
To report the incidence, timing, and magnitude of the benign prostate-specific antigen (PSA) bounce after 125I prostate brachytherapy and correlate the bounce with clinical and/or dosimetric factors.
From March 1999 to August 2003, a total of 292 men received 125I prostate brachytherapy without androgen deprivation or supplemental beam radiotherapy and have PSA follow-up >30 months. Implants were preplanned using transrectal ultrasound (TRUS) and performed under transrectal ultrasound/fluoroscopy guidance using preloaded needles. A PSA bounce is defined as an increase >or=0.2 ng/ml with spontaneous return to prebounce level or lower.
Resolved PSA bounces were seen in 40% of men with follow-up >30 months. Median onset was 15 months, and median magnitude was 0.76 ng/ml. Magnitude >2 ng/ml was seen in 15%. The only clinical or dosimetric factor predictive of bounce in multivariate analysis was younger age. Median time to increasing PSA level indicative of failure was 30 months.
Benign PSA bounces are common after 125I prostate brachytherapy, especially in younger men. An increase >2 ng/ml above the nadir was seen in 15%. Magnitude of increase does not distinguish bounce from failure. Time to the start of the PSA increase can be helpful, but is not absolute. The PSA bounce does not predict subsequent failure. Caution is advised in interpreting an early increasing PSA level in the first 30 months after 125I brachytherapy in favorable-risk patients.
报告¹²⁵I前列腺近距离放疗后良性前列腺特异性抗原（PSA）反弹的发生率、时间及幅度，并将反弹与临床和/或剂量学因素相关联。
1999年3月至2003年8月，共有292名男性接受¹²⁵I前列腺近距离放疗，未进行雄激素剥夺或辅助外照射放疗，且PSA随访时间>30个月。植入治疗采用经直肠超声（TRUS）预先规划，并在经直肠超声/荧光透视引导下使用预装针进行。PSA反弹定义为升高≥0.2 ng/ml且随后自发恢复至反弹前水平或更低。
随访时间>30个月的男性中，40%出现了可缓解的PSA反弹。中位发生时间为15个月，中位幅度为0.76 ng/ml。15%的患者反弹幅度>2 ng/ml。多因素分析中唯一可预测反弹的临床或剂量学因素是年龄较轻。提示治疗失败的PSA水平升高的中位时间为30个月。
¹²⁵I前列腺近距离放疗后良性PSA反弹很常见，尤其是在年轻男性中。最低点以上升高>2 ng/ml的情况在15%的患者中出现。升高幅度无法区分反弹与治疗失败。PSA升高开始的时间可能有帮助，但不绝对。PSA反弹不能预测随后的治疗失败。对于低危患者，在¹²⁵I近距离放疗后最初30个月内解读早期升高的PSA水平时建议谨慎。
