Table 1. Overview of the studies included in the meta-analysis.
| Author | Year | Sample size (LD/HD) |
Median Age | Study period |
Geographic area |
Radiation technology |
Median dose (Gy) | Chemotherapy regimens | Radiation dose (LD/HD, Gy) | Pathological types | Clinical stage | Median follow-up (month) | Quality* | Reference |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tanisada K (<75Y-cohort) | 1998 | 37/125 | 64 | 1992-1994 | Japan | - | 60 | 44%with CT | <60/≥60 | SCC/Ad/Ad-SCC | Ⅰ-Ⅲ | 0.46@ | 7 | [9] |
| Tanisada K (≥75Y-cohort) | 1998 | 27/63 | 80 | 1992-1994 | Japan | - | 60 | 22%with CT | <60/≥60 | SCC/Ad/Ad-SCC | Ⅰ-Ⅲ | 0.46@ | 7 | [9] |
| Minsky BD | 2002 | 109/109 | - | 1995-1999 | USA | Multiple field technique | - | 5-FU/CDDP | 50.4/64.8 | SCC/Ad | T1-4N0-1M0 | 16.4 | 5# | [4] |
| Zhang Z | 2005 | 43/26 | - | 1990-1998 | USA | - | - | 5-FU based or other | 30-51.0/54.0-64.8 | SCC/Ad/other | Ⅱ-Ⅲ | 22 | 7 | [10] |
| Nallapareddy | 2005 | 11/19 | 72.5 | 1999-2004 | USA | - | - | Paclitaxel alone or 5-FU alone or with CDDP/oxaliplatin | <50.4/≥50.4 | SCC/Ad | Ⅰ-Ⅳ | 10 | 6 | [11] |
| Wang S | 2006 | 11/24 | 64 | 1985-2001 | USA | Conventional techniques/3D | - | 5-FU or paclitaxel based | <50/≥50 | SCC/Ad | Ⅰ-Ⅲ | 39 | 6 | [12] |
| Di Fiore F | 2007 | 105& | - | 1997-2003 | France | - | 43.5 | 5-FU /Irinotecan +CDDP | ≤50/>50 | SCC/Ad | Ⅰ-Ⅲ | - | 8 | [13] |
| Huang SH | 2008 | 21/29 | 68 | 1997-2005 | Canada | Hypofractionated RT /3D/IMRT | - | 5-FU-based or CDDP-based | 54/70 | SCC/Ad | Ⅰ-Ⅳ | 3.3@ | 6 | [14] |
| Shen WB | 2011 | 20/48 | 60 | 2003-2008 | China | 2D/3D/IMRT | 60 | 51.5% CT with CDDP based | <60/≥60 | SCC | with supraclavicular LNM | 15 | 6 | [15] |
| Semrau R | 2012 | 203& | 63 | 1995-2005 | Germany | 2D/3D | - | 57.1% CT with 5-FU/CDDP | 40–59.9/≥60 | SCC/Ad | Ⅰ-Ⅳ | 47.9 | 7 | [16] |
| Mirinezhad | 2013 | 151/111 | - | 2006-2011 | Iran | - | 44 | 65.5% CT with CDDP or 5-FU or combined or other | <50/≥50 | SCC/Ad | T2-3N0-1 | - | 7 | [17] |
| Clavier JB | 2013 | 60/83 | - | 2003-2006 | France | 3D | - | CDDP/5FU/Taxane | 38-50.4/50.7-72 | SCC/Ad | Ⅰ-ⅣA | 20.8 | 7 | [18] |
| He L | 2014 | 137/56 | 68 | 1998-2012 | USA | 3D/IMRT /proton beam |
50.4 | 5-FU with platin/taxane | 41.4-50.4/52.2-66 | SCC/Ad | Ⅰ-Ⅳ | 32.4 | 8 | [19] |
| Suh YG | 2014 | 49/77 | - | 1998-2008 | South Korea | 2D/3D | - | 5-FU based or other | 45-59.4/60-75.6 | SCC/Ad/unknown | Ⅱ-Ⅲ | - | 7 | [20] |
| Xu H | 2014 | 16/21 | 76 | 2003-2012 | China | 2D/3D/IMRT /IGRT/VMAT |
51.5 | 54.1% CT with 5-FU or paclitaxel based | ≤50/>50 | SCC | Ⅰ-Ⅳ | 64$ | 5 | [21] |
| Li X | 2015 | 40/76 | 76 | 2008-2013 | China | 3D/IMRT | 60 | 5-FU or taxane based | <60/≥60 | SCC | I-Ⅳ | 16.97 | 7 | [22] |
| Chen CY | 2016 | 324/324 | - | 2008-2013 | Taiwan | 3D/IMRT/IGRT | - | - | 50–50.4/≥60 | SCC | Ⅱ-ⅣA | - | 8 | [23] |
| Gemici C | 2016 | 38/11 | - | - | Turkey | 2D/3D | - | CDDP based or paclitaxel+5-FU | 40-50/50.01-60 | SCC/Ad | T3-4N0-1 | - | 6 | [24] |
| Hirano H | 2016 | 62/180 | - | 2000-2011 | Japan | - | - | CDDP with 5-FU | 50.4/64.8 | SCC | Ⅱ-Ⅲ | - | 8 | [25] |
LD: low dose; HD: high dose; 2D: two dimensional radiation therapy; 3D: three dimensional conformal radiotherapy; IMRT: intensity-modulated radiation therapy; IGRT: image guided radiation therapy; VMAT: volumetric modulated Arc therapy; CT: chemotherapy; CDDP: cisplatin; 5-FU: 5-Fluorouracil; EC: esophageal cancer; SCC: squamous cell carcinomas; Ad: adenocarcinoma; LNM: lymph node metastasis; & in total; @ Year; $ week.
*The quality of non-radomized studies were evaluated by the 9-star Newcastle-Ottawa Scale. # Quality was assessed by the JADAD scale.