Table 2. Trial design of the included trials.
| Parameters | Number | Percentage |
|---|---|---|
| Type of ICI | ||
| Pembrolizumab | 81 | 20.1 |
| Nivolumab | 37 | 9.2 |
| Avelumab | 14 | 3.5 |
| Atezolizumab | 25 | 6.2 |
| Durvalumab | 46 | 11.4 |
| Ipilimumab | 1 | 0.2 |
| Camrelizumab | 31 | 7.7 |
| Sintilimab | 16 | 4.0 |
| Toripalimab | 33 | 8.2 |
| Tislelizumab | 7 | 1.7 |
| PD-1/CTLA-4 combination | 28 | 6.9 |
| ICIs (not specified or novel agents) | 84 | 20.8 |
| Type of RT | ||
| Ultra-hypofractionation (SBRT/SABR) | 132 | 32.8 |
| Conventional fractionation | 187 | 46.4 |
| Moderate fractionation | 16 | 4.0 |
| Unknown | 68 | 16.9 |
| Enrollment | ||
| 0–30 | 149 | 37.0 |
| 31–50 | 91 | 22.6 |
| 51–100 | 72 | 17.9 |
| >100 | 91 | 22.6 |
| Allocation | ||
| Randomized | 116 | 28.8 |
| Nonrandomized | 277 | 68.7 |
| Observation | 10 | 2.5 |
| Conditions | ||
| Head and neck cancer | 75 | 18.6 |
| Breast cancer | 14 | 3.5 |
| GBM | 13 | 3.2 |
| NSCLC | 72 | 17.9 |
| SCLC | 12 | 3.0 |
| Skin cancer | 6 | 1.5 |
| Gastrointestinal cancer | 104 | 25.8 |
| Genitourinary cancer | 23 | 5.7 |
| Gynecological cancer | 17 | 4.2 |
| Lymphoma | 14 | 3.5 |
| Melanoma | 11 | 2.7 |
| Others# | 42 | 10.4 |
| Region | ||
| China | 136 | 33.7 |
| Other Asia | 10 | 2.5 |
| United States | 160 | 39.7 |
| Europe | 78 | 19.4 |
| Canada | 8 | 2.0 |
| Austria | 8 | 2.0 |
| Missing | 3 | 0.7 |
| Funding source | ||
| NIH | 16 | 4.0 |
| Industry | 28 | 6.9 |
| Other | 359 | 89.1 |
#, including multiple solid tumors. ICI, immune checkpoint inhibitor; PD-1, programmed death-1; CTLA-4, cytotoxic T-lymphocyte-associated protein 4; RT, radiotherapy; SBRT, stereotactic body radiotherapy; SABR, stereotactic ablative radiotherapy; GBM, glioblastoma; NSCLC, non-small cell lung cancer; SCLC, small cell lung cancer; NIH, National Institutes of Health.