A phase I dose-escalation trial of stereotactic body radiotherapy using 4 fractions for patients with localized prostate cancer
A phase I dose-escalation trial of stereotactic body radiotherapy using 4 fractions for patients with localized prostate cancer
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DOI：
10.1186/s13014-019-1369-y
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发表时间：
2019-09-02
影响因子：
3.6
通讯作者：
Ishiyama, Hiromichi
中科院分区：
文献类型：
--
作者：
Kainuma, Takuro;Kawakami, Shogo;Ishiyama, Hiromichi
目的报告我们的一期剂量递增研究的结果，立体定向放射治疗（SBRT）使用4个分量治疗局限性前列腺癌患者。材料和方法8gy、8.5 Gy和9gy的分数大小被定义为1、2和3级。规定剂量至少达到计划目标量的95%。所有患者均行图像引导、调强放疗。剂量限制性毒性（DLT）定义为3级或以上的急性毒性。最大耐受剂量（MTD）定义为>= 30%的患者出现DLT的水平。推荐剂量（RD）被定义为比MTD低一个剂量水平。如果3级没有患者出现DLT，则将3级定义为推荐剂量（RD）。结果每个级别入组9例患者。所有患者均为低危或中危。1-3级患者的中位随访时间分别为48.9个月、42.6个月和18.4个月。所有患者均完成方案治疗。每个剂量水平均未出现DLT。因此，Level 3被指定为II期研究的RD。虽然大多数毒性为1级，但与胃肠道毒性相比，泌尿生殖系统毒性更常见。3年生化控制率为90.3%。结论36 Gy分4次进行SBRT治疗局限性前列腺癌是可耐受的，治疗间隔为2天。确认这种治疗的疗效和毒性的II期试验目前正在进行中。
Purpose To report results from our phase I dose-escalation study of stereotactic body radiotherapy (SBRT) using 4 fractions for patients with localized prostate cancer. Materials & methods Fraction sizes of 8 Gy, 8.5 Gy, and 9 Gy were defined as levels 1, 2, and 3. The prescribed dose was delivered to at least 95% of the planning target volume. Image-guided, intensity-modulated radiotherapy was delivered to all patients. Dose-limiting toxicity (DLT) was defined as acute toxicity of Grade 3 or higher. The maximum tolerated dose (MTD) was defined as the level at which >= 30% of patients showed DLT. The recommended dose (RD) was defined to be one dose level below the MTD. If no patients at level 3 showed DLT, level 3 was defined as the recommended dose (RD). Results Nine patients were enrolled in each level. All patients were low or intermediate risk. Median durations of follow-up for patients at levels 1-3 were 48.9 months, 42.6 months, and 18.4 months, respectively. Protocol treatment was completed for all patients. No patient showed DLT at each dose level. Level 3 was therefore designated as the RD for the phase II study. Although most toxicities were Grade 1, genitourinary toxicity was common compared to gastrointestinal toxicity. Three-year biochemical control rate was 90.3%. Conclusion The dose level of 36 Gy in 4 fractions with a 2-day break was tolerable and highly encouraging for SBRT of localized prostate cancer. The phase II trial to confirm the efficacy and toxicity of this treatment is now on going.