Table 1.
Characteristics of 12 included studies.
| Study (Publication Year) | Nation | Multicenter | Study Design | Recruitment Period | Response Criteria | Response Assessment Time after Initiation of Therapy | ICI Used | Radio-Therapy | Symptoms | Analysis | Treated No. | ICI - Line of Therapy | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1st | 2nd | 3rd | 3rd> | ||||||||||||
| ICI monotherapy | |||||||||||||||
| Bjornhart B et al (2019) [7] | Denmark | No | Retrospective | 2015.09–2018.04 | RECIST 1.1 | 8~9 weeks | Pembrolizumab or nivolumab |
- | Mixed | Per-patient | 21 | 2 * | 7 * | 7 * | 5 * |
| Dudnik E et al (2016) [8] | Israel | Yes | Retrospective | 2015.02–2015.12 | mRECIST 1.1 | NR | Nivolumab | - | Asymptomatic | Per-patient | 5 | - | |||
| Gauvain C et al (2018) [9] | France | Yes | Retrospective | 2015.05–2016.08 | RECIST 1.1 | 2 months | Nivolumab | - | NR | Per-patient | 30 | - | |||
| Goldberg SB et al (2016) [10] | USA | No | Phase II trial | 2014.03–2015.05 | mRECIST 1.1 | 8 weeks | Pembrolizumab | - | Asymptomatic | Per-patient | 18 | 5 * | 6 * | 3 * | 4 * |
| Hendriks LEL et al (2019) [24] | France, Netherlands | Yes | Retrospective | 2012.11–2018.07 | NR | 6–9 weeks | Nivolumab | - | Mixed | Per-patient | 5 | 0 | 1 | 2 | 2 |
| Kim R et al (2019) [11] | Korea | Yes | Retrospective | 2014.02–2016.11 | mRECIST 1.1 | NR | Pembrolizumab or nivolumab | - | NR | Per-patient | 18 | 0 * | 6 * | 7 * | 5 * |
| Song P et al (2019) [12] | China | No | Retrospective | 2015.08–2018.02 | RECIST 1.1 | NR | Pembrolizumab or nivolumab or atezolizumab |
- | Mixed | Per-patient | 5 | - | |||
| ICI combined with chemotherapy | |||||||||||||||
| Afzal MZ et al (2018) [25] | USA | No | Retrospective | 2016.01–2017.12 | RECIST 1.1 | NR | Pembrolizumab | - | NR | Per-patient | 5 | 3 ** | 3 ** | ||
| ICI combined with radiotherapy | |||||||||||||||
| Ahmed KA et al (2017) [26] | USA | No | Retrospective | 2014.02–2016.10 | iRANO | 2–3 months | Nivolumab or durvalumab |
SRS or FSRT | NR | Per-lesion | 49 | - | |||
| Schapira E et al (2018) [27] | USA | No | Retrospective | 2012.01–2017.12 | NR | NR | Pembrolizumab or nivolumab or atezolizumab |
SRS | NR | Per-lesion | 85 | 0 | - | ||
| Shepard MJ et al (2019) [13] | USA | No | Retrospective | 2012.01–2018.12 | RANO-BM | 2–3 months | Pembrolizumab or nivolumab or atezolizumab |
SRS | NR | Per-patient | 16 | - | |||
| Singh C et al (2019) [14] | USA | No | Retrospective | 2013.01–2016.12 | RANO-BM | 1.5, 3, 6, 9, and 12 months | Pembrolizumab or nivolumab or nivolumab + ipilimumab or atezolizumab |
SRS | NR | Per-lesion | 291 | 0 | - | ||
ICI = immune checkpoint inhibitor; NR = not reported; RECIST = Response Evaluation Criteria in Solid Tumors; mRECIST = modified RECIST; RANO = Response Assessment in Neuro-Oncology; iRANO = immunotherapy RANO; RANO-BM = RANO brain metastases; SRS = stereotactic radiosurgery; FSRT = fractionated stereotactic radiotherapy. * Only previous systemic therapies were considered when determining the line of therapy. ** One patient was not radiographically evaluated.