Kilburn Jeremy M, Lucas John T, Soike Michael H, Ayala-Peacock Diandra N, Blackstock Arthur W, Hinson William H, Munley Michael T, Petty William J, Urbanic James J
Radiation Oncology, Wake Forest School of Medicine.
Medicine, Division of Hematology/Oncology, Wake Forest School of Medicine.
Cureus. 2016 Jan 23;8(1):e466. doi: 10.7759/cureus.466.
We hypothesized that omission of clinical target volumes (CTV) in lung cancer radiotherapy would not compromise control by determining retrospectively if the addition of a CTV would encompass the site of failure.
Stage II-III patients were treated from 2009-2012 with daily cone-beam imaging and a 5 mm planning target volume (PTV) without a CTV. PTVs were expanded 1 cm and termed CTVretro. Recurrences were scored as 1) within the PTV, 2) within CTVretro, or 3) outside the PTV. Locoregional control (LRC), distant control (DC), progression-free survival (PFS), and overall survival (OS) were estimated.
Among 110 patients, Stage IIIA 57%, IIIB 32%, IIA 4%, and IIB 7%. Eighty-six percent of Stage III patients received chemotherapy. Median dose was 70 Gy (45-74 Gy) and fraction size ranged from 1.5-2.7 Gy. Median follow-up was 12 months, median OS was 22 months (95% CI 19-30 months), and LRC at two years was 69%. Fourteen local and eight regional events were scored with two CTVretro failures equating to a two-year CTV failure-free survival of 98%.
Omission of a 1 cm CTV expansion appears feasible based on only two events among 110 patients and should be considered in radiation planning.
我们假设在肺癌放疗中省略临床靶区（CTV）不会影响治疗效果，通过回顾性分析添加CTV是否会覆盖失败部位来进行验证。
2009年至2012年期间，对II - III期患者采用每日锥形束成像和5毫米的计划靶区（PTV）进行治疗，不设CTV。将PTV扩大1厘米并称为CTVretro。复发情况分为1）在PTV内，2）在CTVretro内，或3）在PTV外。评估局部区域控制（LRC）、远处控制（DC）、无进展生存期（PFS）和总生存期（OS）。
110例患者中，IIIA期占57%，IIIB期占32%，IIA期占4%，IIB期占7%。86%的III期患者接受了化疗。中位剂量为70 Gy（45 - 74 Gy），分次剂量范围为1.5 - 2.7 Gy。中位随访时间为12个月，中位OS为22个月（95% CI 19 - 30个月），两年的LRC为69%。记录到14例局部和8例区域事件，其中两例CTVretro失败，相当于两年的CTV无失败生存期为98%。
基于110例患者中仅出现两例事件，省略1厘米的CTV扩展似乎是可行的，在放疗计划中应予以考虑。
