Table 2 The margins to encompass the CTVpost in anterior-posterior, lateral, and superior-inferior directions

CTV-N (upper)

≤ 1 mm

1 (0.4) *

0*

0*

1(0.4) *

47 (18.6) *

-

≤ 2 mm

9 (3.6) *

5 (2) *

9 (3.6) *

22 (8.7) *

114 (45.1) *

-

≤ 3 mm

154 (60.9) *

199 (78.7) *

189 (74.7) *

206 (81.4) *

226 (89.3) *

-

≤ 4 mm

237 (93.7)

241 (95.3)

243 (96.0)

246 (97.2)

246 (97.2)

-

≤ 5 mm

253 (100)

253 (100)

253 (100)

253 (100)

253 (100)

-

CTV-N (middle)

≤ 1 mm

0*

0*

0*

1 (0.4) *

-

-

≤ 2 mm

4 (1.6) *

7 (2.8) *

6 (23.7) *

9 (3.6) *

-

-

≤ 3 mm

145 (57.3) *

218 (86.2) *

205 (81) *

217 (85.8) *

-

-

≤ 4 mm

232 (91.7)

249 (98.4)

242 (95.7)

247 (97.6)

-

-

≤ 5 mm

253 (100)

253 (100)

253 (100)

253 (100)

-

-

CTV-N (lower)

≤ 1 mm

0*

0*

0*

0*

-

37 (14.6) *

≤ 2 mm

17 (6.7) *

5 (2) *

2 (0.8) *

1 (0.4) *

-

135 (53.4) *

≤ 3 mm

172 (70) *

179 (70.8) *

158 (62.5) *

167 (66.0) *

-

238 (94.1)

≤ 4 mm

234 (92.5)

239 (94.5)

236 (93.3)

241 (95.3)

-

251 (99.2)

≤ 5 mm

253 (100)

253 (100)

253 (100)

253 (100)

-

253 (100)

CTV-V

≤ 1 mm

5 (2) *

3 (1.2) *

1 (0.4) *

3 (1.2) *

66 (26.1) *

67 (26.5) *

≤ 2 mm

31 (12.3) *

17 (6.7) *

26 (10.3) *

27 (10.7) *

129 (51) *

146 (57.7) *

≤ 3 mm

121 (47.8) *

91 (40) *

159 (62.8) *

159 (62.8) *

224 (88.5) *

223 (88.1) *

≤ 4 mm

193 (76.3) *

184 (72.7) *

216 (85.4) *

220 (87) *

238 (94.1)

236 (93.3)

≤ 5 mm

251 (99.2)

251 (99.2)

252 (99.6)

252 (99.6)

253 (100)

253 (100)