Background

The aim of this study was to evaluate the long-term efficacy and safety of whole pelvic intensity-modulated radiation therapy with a simultaneous-integrated boost (WP-SIB-IMRT) for locally advanced prostate cancer (LAPCa).

Methods

All patients with cT3–4N0M0 prostate cancer treated with WP-SIB-IMRT between February 2006 and September 2009 at our institution were analyzed retrospectively. The prescribed dose was 78 Gy to the prostate and 58.5 Gy to the prophylactic pelvic lymph nodal area in 39 fractions delivered using the simultaneous-integrated boost technique. All patients received short-term neoadjuvant androgen-deprivation therapy alone (median 8.3 months). Propensity-score matching (PSM) analysis was performed to evaluate the additional benefit of prophylactic whole pelvic radiation therapy (WPRT), using the cohort of 203 LAPCa patients treated with prostate-only IMRT (PO-IMRT).

Results

In total, 47 consecutive patients were analyzed. The median estimated risk of pelvic lymph node involvement was 57.5%. The median follow-up period was 10.5 years. The 10 year prostate cancer-specific survival and biochemical failure (BF) rates were 92.2 and 54.8%, respectively. The 10 year cumulative incidence rates of ≥ grade 2 late genitourinary and gastrointestinal toxicities were 21.6 and 17.2%, respectively. From a total of 250 patients, PSM analysis identified 76 patients with similar characteristics, and no significant difference in BF rates was observed between WP-SIB-IMRT and PO-IMRT cohorts (p = 0.261).

Conclusions

WP-SIB-IMRT for LAPCa was safe over long-term observation, although no clear benefit of WPRT was observed among our small and highly selected cohort. Regarding the additional efficacy of WPRT, further investigations are needed.

中文翻译：

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大剂量全盆腔 IMRT 治疗高危局限性前列腺癌的长期安全性通过 10 年随访

背景

本研究的目的是评估全盆腔调强放疗联合同步强化 (WP-SIB-IMRT) 治疗局部晚期前列腺癌 (LAPCa) 的长期疗效和安全性。

方法

回顾性分析了 2006 年 2 月至 2009 年 9 月在我们机构接受 WP-SIB-IMRT 治疗的所有 cT3-4N0M0 前列腺癌患者。处方剂量为前列腺 78 Gy 和预防性盆腔淋巴结区域 58.5 Gy，分 39 次使用同时整合加强技术递送。所有患者仅接受短期新辅助雄激素剥夺治疗（中位 8.3 个月）。使用 203 名仅接受前列腺 IMRT (PO-IMRT) 治疗的 LAPCa 患者队列，进行了倾向评分匹配 (PSM) 分析以评估预防性全盆腔放射治疗 (WPRT) 的额外益处。

结果

总共分析了 47 名连续患者。盆腔淋巴结受累的中位估计风险为 57.5%。中位随访期为 10.5 年。10 年前列腺癌特异性存活率和生化失败 (BF) 率分别为 92.2% 和 54.8%。≥ 2 级晚期泌尿生殖系统和胃肠道毒性的 10 年累积发生率分别为 21.6% 和 17.2%。从总共 250 名患者中，PSM 分析确定了 76 名具有相似特征的患者，并且在 WP-SIB-IMRT 和 PO-IMRT 队列之间没有观察到 BF 率的显着差异（p  = 0.261）。

结论

WP-SIB-IMRT 对 LAPCa 的长期观察是安全的，尽管在我们的小而高度选择的队列中没有观察到 WPRT 的明显益处。关于 WPRT 的额外功效，需要进一步研究。