Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Department of Radiation Oncology, University of Toronto, Canada.
Department of Biostatistics, Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.
Radiother Oncol. 2017 Jun;123(3):459-465. doi: 10.1016/j.radonc.2017.04.003. Epub 2017 Apr 20.
Dose-escalated radiotherapy (DE) improves outcomes in localized prostate cancer (PCa). The impact of DE in the context of image-guided radiotherapy (IGRT) remains unknown. Herein, we determined outcomes of three sequential cohorts treated with progressive DE-IGRT.
We analyzed data from 1998 to 2012. Patients treated with radical radiotherapy were included, with three sequential institutional schedules: (A) 75.6Gy, (B) 79.8Gy, (C) 78Gy, with 1.8, 1.9 and 2Gy/fraction, respectively. IGRT consisted of fiducial markers and daily EPID (A, B) or CBCT (C).
961 patients were included, with median follow-up of 6.1y. 30.5%, 32.6% and 36.9% were treated in A, B and C, respectively. Risk category distribution was 179 (18.6%) low-, 653 (67.9%) intermediate- and 129 (13.5%) high-risk. PSA, T-category, androgen deprivation use and risk distribution were similar among groups. BCR (biochemical recurrence) was different (p<0.001) between A, B and C with 5-year rates of 23%, 17% and 9%, respectively (HR 2.68 [95% CI 1.87-3.85] and 1.92 [95% CI 1.33-2.78] for A and B compared to C, respectively). Findings were most significant in the intermediate-risk category. Metastasis, cause-specific-death and toxicities were not different between cohorts.
Our findings suggest continuous BCR improvement with progressive DE-IGRT. Prospective validation considering further DE with IGRT seems warranted.
递增剂量放疗（DE）可改善局限性前列腺癌（PCa）的治疗效果。在图像引导放疗（IGRT）的背景下，DE 的影响尚不清楚。在此，我们分析了采用逐步递增 DE-IGRT 治疗的 3 个连续队列的结果。
我们分析了 1998 年至 2012 年的数据。纳入接受根治性放疗的患者，采用 3 种连续的机构治疗方案：（A）75.6Gy、（B）79.8Gy、（C）78Gy，分次剂量分别为 1.8、1.9 和 2Gy。IGRT 包括基准标记物和每日 EPID（A、B）或 CBCT（C）。
共纳入 961 例患者，中位随访时间为 6.1 年。A、B 和 C 组的患者分别占 30.5%、32.6%和 36.9%。风险类别分布为 179 例（18.6%）低危、653 例（67.9%）中危和 129 例（13.5%）高危。各组间 PSA、T 分期、雄激素剥夺治疗和风险分布相似。A、B 和 C 组之间的 BCR（生化复发）不同（p<0.001），5 年 BCR 发生率分别为 23%、17%和 9%（A 和 B 组与 C 组相比，HR 分别为 2.68[95%CI 1.87-3.85]和 1.92[95%CI 1.33-2.78]）。在中危组中，结果最为显著。各组间转移、特定原因死亡和毒性无差异。
我们的研究结果表明，随着递增剂量 IGRT 的应用，BCR 不断改善。考虑进一步递增 DE 结合 IGRT 的前瞻性验证似乎是合理的。
