In patients presenting with limited nodal recurrence following radical prostatectomy (RP), stereotactic body radiotherapy (SBRT) results might improve with a better case selection. Single-institution retrospective analysis of patients presenting with 1–3 lymph node (LN) recurrences (N1 or M1a) on 18F-Choline PET/CT. Prior therapy included radical prostatectomy (RP) ± salvage radiotherapy (RT), in absence of any systemic therapy. Outcome parameters were biochemical response (BR), time to biochemical recurrence (TBR) and time interval between SBRT and androgen deprivation therapy start (TADT). Time to event endpoints was analysed using Kaplan-Meier method. Potential prognostic factors were examined using univariate proportional hazards regression for TADT and logistic regression for BR. The optimal cut-off point for LN size was calculated using the Contal and O’Quigley method. 25 patients fulfilling study criteria were treated with SBRT from January 2010 to January 2015 and retrospectively analysed. Median follow up was 18 months and median LN diameter 10.5 mm. SBRT was delivered to a median dose of 36 Gy in three fractions (range: 30–45 Gy). BR was reached in 52% of cases. Median TBR was 11.9 months and significantly longer in patients with larger LN (Hazard ratio [HR] = 0.87, P = 0.03). Using 14 mm as cut off for LN, median TBR was 10.8 months for patients with small LN (18 patients), and 21.2 months for patients with large LN (6 patients) (P unadjusted = 0.009; P adjusted = 0.099). ADT was started in 32% of patients after a median follow-up of 18 months. For PCa patients with 1–3 LN recurrence after RP (± salvage RT), SBRT might result in a better biochemical control when delivered to larger sized (≥ 14 mm) LN metastases. This study is hypothesis generating and results should be tested in a larger prospective trial.

中文翻译：

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仅限于淋巴结的少发性前列腺癌对挽救性立体定向放射疗法的反应的预测因素：单一机构的经验

对于根治性前列腺切除术（RP）后淋巴结复发受限的患者，采用更好的病例选择可能会改善立体定向身体放疗（SBRT）的结果。对18F-胆碱PET / CT上出现1-3个淋巴结（LN）复发（N1或M1a）的患者进行单机构回顾性分析。先前的治疗方法包括在没有任何全身治疗的情况下进行前列腺癌根治术（RP）±抢救性放疗（RT）。结果参数是生化反应（BR），生化复发时间（TBR）以及SBRT和雄激素剥夺治疗开始之间的时间间隔（TADT）。使用Kaplan-Meier方法分析事件到达终点的时间。使用TADT的单变量比例风险回归和BR的logistic回归检查潜在的预后因素。使用Contal和O'Quigley方法计算LN尺寸的最佳截止点。从2010年1月至2015年1月，对25例符合研究标准的患者进行SBRT治疗，并进行回顾性分析。中位随访期为18个月，中位LN直径为10.5 mm。SBRT分三部分（范围：30–45 Gy）递送至中值剂量，剂量为36 Gy。在52％的病例中达到了BR。LN中位值TBR为11.9个月，而LN值较大的患者则明显更长（危险比[HR] = 0.87，P = 0.03）。使用14 mm作为LN的截止值，小LN患者（18例）的中位TBR为10.8个月，大LN患者（6例）的中位TBR为21.2个月（P未调整= 0.009； P调整= 0.099）。中位随访18个月后，有32％的患者开始进行ADT。对于RP后（±抢救性RT）复发1-3 LN的PCa患者，当SBRT传递至更大尺寸（≥14 mm）的LN转移灶时，可能会更好地控制生化。该研究是产生假设的结果，应在较大的前瞻性试验中测试结果。