Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital, 3 Lok Man Road, Chai Wan, Hong Kong.
Radiother Oncol. 2011 Nov;101(2):298-302. doi: 10.1016/j.radonc.2011.08.015. Epub 2011 Sep 8.
To compare the dosimetric performance of three different treatment techniques - conformal radiotherapy (CRT), double arcs volumetric modulated arc therapy (RapidArc, RA) and Hybrid-RapidArc (H-RA) for locally-advanced non-small cell lung cancer (NSCLC).
CRT, RA and H-RA plans were optimized for 24 stage III NSCLC patients. The target prescription dose was 60Gy. CRT consisted of 5-7 coplanar fields, while RA comprised of two 204(o) arcs. H-RA referred to two 204(o) arcs plus 2 static fields, which accounted for approximately half of the total dose. The plans were optimized to fulfill the departmental plan acceptance criteria.
RA and H-RA yielded a 20% better conformity compared with CRT. Lung volume receiving >20Gy (V20) and mean lung dose (MLD) were the lowest in H-RA (V20 1.7% and 2.1% lower, MLD 0.59Gy and 0.41Gy lower than CRT & RA respectively) without jeopardizing the low-dose lung volume (V5). H-RA plans gave the lowest mean maximum spinal cord dose (34.4Gy, 3.9Gy<CRT and 2.2Gy<RA plans) and NTCP of lung. Higher average MU per fraction (addition 52.4MU) was observed with a reduced treatment time compared with CRT plans.
The H-RA technique was superior in dosimetric outcomes for treating locally-advanced NSCLC compared to CRT and RA.
比较三种不同治疗技术——适形放疗（CRT）、双弧容积调强弧形放疗（RapidArc，RA）和混合 RapidArc（H-RA）——治疗局部晚期非小细胞肺癌（NSCLC）的剂量学性能。
为 24 例 III 期 NSCLC 患者优化 CRT、RA 和 H-RA 计划。靶区处方剂量为 60Gy。CRT 由 5-7 个共面野组成，而 RA 由两个 204(o) 弧组成。H-RA 是指两个 204(o) 弧加 2 个静态野，占总剂量的一半左右。计划优化以满足部门计划接受标准。
RA 和 H-RA 与 CRT 相比，一致性提高了 20%。接受 >20Gy 的肺体积（V20）和平均肺剂量（MLD）在 H-RA 中最低（V20 分别低 2.1%和 2.1%，MLD 分别低 0.59Gy 和 0.41Gy），而不会危及低剂量肺体积（V5）。H-RA 计划使平均脊髓最大剂量（34.4Gy）和肺 NTCP 最低（分别比 CRT 和 RA 计划低 3.9Gy 和 2.2Gy）。与 CRT 计划相比，每个分数的平均 MU 更高（增加 52.4MU），同时治疗时间缩短。
与 CRT 和 RA 相比，H-RA 技术在治疗局部晚期 NSCLC 的剂量学结果方面更优。
