Table 1.
Characteristics of all clinical trials included in the meta-analysis.
| Studies | Country |
Study Design |
Inclusion Period |
Age (Median, Range) |
Sample Size (LD/HD) |
Stage |
Location (Cervical/Upper/ Middle/Lower/ GJ/Unknown) |
Histology (SCC/AC/ Others) |
Radiation Technology |
Radiotherapy Dose |
Concurrent Chemotherapy |
Follow-Up Time (Median, Range) |
Studies' Quality* |
|
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| LD-RT | HD-RT | |||||||||||||
| (11) | China | Prospective | 2007.1–2007.12 | 57, 46–68 | 24/20 | I–III* | 44 (cervical and upper) | 44/0/0 | IMRT | 60 Gy/2 Gy | 63.9 Gy/2.27 Gy | PF | 36 m, – | 5 |
| (12) | France | Retrospective | 2003.1–2006.12 | 65, 42–81 | 60/83 | I–IVa* | 4/29/52/56/2 | 113/30/0 | 3D-CRT | 38–50.4 Gy/ 1.8–2 Gy |
50.7–72 Gy/ 1.8–2.5 Gy |
Cisplatin/5- FU/taxane |
20.8 m, 2.8–92.4 m |
6 |
| (13) | USA | Retrospective | 1998.5–2012.5 | 68, 30–89 | 137/56 | I–IV*/** | 0/66/40/87/0/0 | 193/0/0 | 3D-CRT/IMRT | 41.4–50.4 Gy/1.6–2.4 Gy | 52.2–66 Gy/1.6–2.4 Gy | Platin-/taxane-based | 32.4 m, 2.5–161.3 m |
6 |
| (14) | USA | Retrospective | 2004–2012 | 69, 26–90 | 3821/3033 | I–III*/** | 859 (cervical and upper)/1549/ 3693/753/0 |
3049/ 3602/203 |
3D-CRT/IMRT | ≤ 50.4 Gy/– | >50.4 Gy/– | – | – | 6 |
| (15) | Taiwan area | Retrospective | 2008–2013 | – | 324/324 | I–IVa | 40/608 (/upper/middle/ lower/GJ/ unknown) |
648/0/0 | CRT/IMRT | 50–50.4 Gy/– | ≥60 Gy/– | – | – | 5 |
| (16) | Taiwan area | Retrospective | 2006.1–2014.12 | 57, 29–92 | 1134/927 | I–III | 2061 (thoracic) | 2061/0/0 | IMRT | 45–59.4 Gy/1.8 Gy | 60–72 Gy/1.8 Gy | – | 26.4 m, 19.4–33.2 m |
7 |
| (17) | China | Retrospective | 2010–2016 | 68, 36–81 | 63/74 | I–III** | 0/29/57/51/0/0 | 137/0/0 | 3D-CRT/IMRT | 50–50.4 Gy/1.8–2 Gy | ≥59.4 Gy/1.8–2 Gy | 5-FU based | 27.5 m, 6.4–79.5 m |
7 |
| (18) | Korea | Retrospective | 1994.2–2013.5 | 67, 30–86 | 120/116 | II–III** | 16/58/113/49/0 | 230/6/0 | 3D-CRT/IMRT/TOMO | <60 Gy/1.8–2 Gy | ≥60 Gy/1.8–2 Gy | PF/5-FU/ Cisplatin |
19.4 m, 2.2–164.7 m |
6 |
| (19) | Taiwan area | Retrospective | 2007–2015 | 56, 40–83 | 42/42 | I–III** | 38/28/18 (cervical and upper/ middle/lower) |
84/0/0 | IMRT/VMAT | 44–50.4 Gy/– | 52.2–70 Gy/– | – | 23.2 m, – | 6 |
| (20) | China | Retrospective | 2004–2013 | – | 190/190 | I–IVa*** | 137/243 (cervical and upper/ middle and lower) |
380/0/0 | 3D-CRT/IMRT | 50.4–54 Gy/1.8 Gy | 60 Gy/2 Gy | PF/TP | 87 m, – | 8 |
| (21) | China | Retrospective | 2009.1–2014.3 | 67, 46–79 | 43/37 | II–III** | 0/14/31/35/0/0 | 80/0/0 | 3D-CRT/IMRT | 50.4–56 Gy/1.8–2 Gy | 59.4–64.8 Gy/1.8–2 Gy | PF/TP/S-1 | 54 m, −91 m | 6 |
| (22) | Taiwan area | Retrospective | 2011–2015 | 59, – | 18/18 | I–III** | – | 36/0/0 | IMRT | 50 Gy/1.8–2 Gy | 60 Gy/1.8–2 Gy | – | 10 m, 2–82 m | 6 |
LD, low dose; HD, high dose; RT, radiotherapy; SCC, squamous cell cancer; AC, adenocarcinoma; 3DRT, three-dimensional conformal radiotherapy; IMRT, intensity-modulated radiotherapy; VMAT, volume-modulated arc therapy; TOMO, helical tomotherapy; 5-FU, 5-fluorouracil; PF, cisplatin + 5-fluorouracil; PF, cisplatin + 5-fluorouracil; TP, paclitaxel + cisplatin;
staged according to the sixth edition of the American Joint Committee on Cancer (AJCC) staging manual for esophageal carcinoma;
staged according to the seventh edition of the American Joint Committee on Cancer (AJCC) staging manual for esophageal carcinoma;
staged according to the eighth edition of the American Joint Committee on Cancer (AJCC) staging manual for esophageal carcinoma; m, month.