ACRF Image X Institute, University of Sydney, Sydney, Australia.
ACRF Image X Institute, University of Sydney, Sydney, Australia; School of Biomedical Engineering, University of Technology, Sydney, Sydney, Australia.
Int J Radiat Oncol Biol Phys. 2020 Jul 1;107(3):530-538. doi: 10.1016/j.ijrobp.2020.03.014. Epub 2020 Mar 29.
Kilovoltage intrafraction monitoring (KIM) is a novel software platform implemented on standard radiation therapy systems and enabling real-time image guided radiation therapy (IGRT). In a multi-institutional prospective trial, we investigated whether real-time IGRT improved the accuracy of the dose patients with prostate cancer received during radiation therapy.
Forty-eight patients with prostate cancer were treated with KIM-guided SABR with 36.25 Gy in 5 fractions. During KIM-guided treatment, the prostate motion was corrected for by either beam gating with couch shifts or multileaf collimator tracking. A dose reconstruction method was used to evaluate the dose delivered to the target and organs at risk with and without real-time IGRT. Primary outcome was the effect of real-time IGRT on dose distributions. Secondary outcomes included patient-reported outcomes and toxicity.
Motion correction occurred in ≥1 treatment for 88% of patients (42 of 48) and 51% of treatments (121 of 235). With real-time IGRT, no treatments had prostate clinical target volume (CTV) D98% dose 5% less than planned. Without real-time IGRT, 13 treatments (5.5%) had prostate CTV D98% doses 5% less than planned. The prostate CTV D98% dose with real-time IGRT was closer to the plan by an average of 1.0% (range, -2.8% to 20.3%). Patient outcomes showed no change in the 12-month patient-reported outcomes compared with baseline and no grade ≥3 genitourinary or gastrointestinal toxicities.
Real-time IGRT is clinically effective for prostate cancer SABR.
千伏级分次内监测（KIM）是一种在标准放射治疗系统上实现的新型软件平台，能够实现实时图像引导放射治疗（IGRT）。在一项多机构前瞻性试验中，我们研究了实时 IGRT 是否能提高接受放射治疗的前列腺癌患者的剂量准确性。
48 例前列腺癌患者接受 KIM 引导的 SABR 治疗，单次剂量 36.25Gy，共 5 次。在 KIM 引导治疗过程中，通过床位移位或多叶准直器跟踪来校正前列腺运动。采用剂量重建方法评估有无实时 IGRT 时靶区和危及器官的剂量分布。主要结果是实时 IGRT 对剂量分布的影响。次要结果包括患者报告的结果和毒性。
88%（42/48）的患者和 51%（121/235）的治疗有≥1 次运动校正。有实时 IGRT 时，没有治疗的前列腺临床靶区（CTV）D98%剂量比计划少 5%。无实时 IGRT 时，有 13 次治疗（5.5%）的前列腺 CTV D98%剂量比计划少 5%。有实时 IGRT 时，前列腺 CTV D98%剂量比计划平均更接近 1.0%（范围：-2.8%至 20.3%）。与基线相比，患者在 12 个月时的报告结果没有变化，也没有出现≥3 级的泌尿生殖系统或胃肠道毒性。
实时 IGRT 对前列腺癌 SABR 是有效的。
