Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, North 15 West 7, Kita-ku, Sapporo 060-8638, Japan.
Radiat Oncol. 2013 Mar 21;8:69. doi: 10.1186/1748-717X-8-69.
To clarify the clinical outcomes of two dose schedule of stereotactic body radiotherapy (SBRT) for stage I non-small cell lung cancer (NSCLC) using a real-time tumor-tracking radiation therapy (RTRT) system in single institution.
Using a superposition algorithm, we administered 48 Gy in 4 fractions at the isocenter in 2005-2006 and 40 Gy in 4 fractions to the 95% volume of PTV in 2007-2010 with a treatment period of 4 to 7 days. Target volume margins were fixed irrespective of the tumor amplitude.
In total, 109 patients (79 T1N0M0 and 30 T2N0M0). With a median follow-up period of 25 months (range, 4 to 72 months), the 5-year local control rate (LC) was 78% and the 5-year overall survival rate (OS) was 64%. Grade 2, 3, 4, and 5 radiation pneumonitis (RP) was experienced by 15 (13.8%), 3 (2.8%), 0, and 0 patients, respectively. The mean lung dose (MLD) and the volume of lung receiving 20 Gy (V20) were significantly higher in patients with RP Grade 2/3 than in those with RP Grade 0/1 (MLD p = 0.002, V20 p = 0.003). There was no correlation between larger maximum amplitude of marker movement and larger PTV (r = 0.137), MLD (r = 0.046), or V20 (r = 0.158).
SBRT using the RTRT system achieved LC and OS comparable to other SBRT studies with very low incidence of RP, which was consistent with the small MLD and V20 irrespective of tumor amplitude. For stage I NSCLC, SBRT using RTRT was suggested to be reliable and effective, especially for patients with large amplitude of tumor movement.
为了明确在单机构中使用实时肿瘤跟踪放射治疗（RTRT）系统对 I 期非小细胞肺癌（NSCLC）进行两种剂量分割立体定向体放射治疗（SBRT）的临床结果。
在 2005-2006 年，我们使用叠加算法在等中心点给予 48 Gy/4 次分割，在 2007-2010 年给予 40 Gy/4 次分割，使 PTV 的 95%体积达到 40 Gy。目标体积边界固定，与肿瘤幅度无关。
共纳入 109 例患者（79 例 T1N0M0 和 30 例 T2N0M0）。中位随访时间为 25 个月（4-72 个月），5 年局部控制率（LC）为 78%，5 年总生存率（OS）为 64%。2 级、3 级、4 级和 5 级放射性肺炎（RP）的发生率分别为 15（13.8%）、3（2.8%）、0 和 0 例。RP 2/3 级患者的平均肺剂量（MLD）和 20 Gy 体积（V20）明显高于 RP 0/1 级患者（MLD p=0.002，V20 p=0.003）。标记物运动最大幅度与 PTV 较大（r=0.137）、MLD 较大（r=0.046）或 V20 较大（r=0.158）之间无相关性。
使用 RTRT 系统的 SBRT 实现了与其他 SBRT 研究相当的 LC 和 OS，放射性肺炎发生率非常低，这与 MLD 和 V20 较小有关，而与肿瘤幅度无关。对于 I 期 NSCLC，使用 RTRT 的 SBRT 是可靠和有效的，特别是对于肿瘤运动幅度较大的患者。
