Table 1.
Characteristics of studies included in the meta-analysis and meta-regression analysis of categorical and continuous moderator variables related to overall response rate
| Variables | Study level n, median % (range) | Patients | Age | Gender | KPS |
|---|---|---|---|---|---|
| Number of studies Median/% (range) |
28 studies (2 studies with two arms counted as a study) | 28 studies 1986 (15–505) |
28 studies 66 years (65–78 y) |
26 studies Female: 24% patients (18–73%) Male: 76% patients (27–82%) |
24 studies 70 (60–80) |
| Metaregression analysis | |||||
|
Histology Squamous cell carcinoma |
26 studies, 93% patients (60–100%) | Coefficients | Lower bound | Upper bound | p-value |
| Total BED Gy10 | 22 studies, median 56 Gy10 (30–72 Gy10) BED > 60 Gy10 BED 40–60 Gy10 BED < 40 Gy10 |
Ref −0.4 −0.7 |
−0.6 −1.1 |
−0.2 −0.3 |
0.001 0.001 |
|
RT course Cycled Long Short |
8 studies — 315 (21–75) patients 10 studies — 660 (25–158) patients 10 studies — 1011 (17–505) patients |
Ref −0.012 0.23 |
−0.13 0.10 |
0.10 0.44 |
0.88 0.01 |
|
RT technique 2D-RT 3D-RT Mixed IMRT SBRT |
12 studies — 1289 (23–550) patients 3 studies — 98 (30–35) patients 5 studies — 393 (21–148) patients 5 studies — 127 (17–34) patients 3 studies — 79 (15–44) patients |
Ref 0.08 −0.06 −0.13 0.47 |
−0.08 −0.24 −0.32 0.06 |
0.25 0.10 0.05 0.88 |
0.31 0.44 0.16 0.02 |
|
Study design Prospective Randomized Retrospective |
10 studies — 592 (25–158) patients 2 studies — 80 (17–23) patients 16 studies — 1314 (15–505) patients |
Ref 0.23 0.24 |
0.04 0.10 |
0.4 0.38 |
0.015 0.001 |
|
Intercept Total BED |
22 studies, median 56 Gy10 (30–72 Gy10) | 2.4 0.03 |
1.4 0.01 |
3.4 0.4 |
0.001 0.001 |
BED— biological effective dose; 2D-RT — conventional radiotherapy; 3D-RT — conformational radiation therapy; IMRT — intensity-modulated radiation therapy; SBRT — stereotactic body radiation therapy