Table 4.
Summary of subgroup analysis results
| Outcome/subgroup | CIRT cohort no. | PRT cohort no. | IMRT cohort no. | Total cohort no. | Sample size | Mean follow‐up time (mo) | Survival, 95% CI | I 2, % |
|---|---|---|---|---|---|---|---|---|
| OS | ||||||||
| Naive | 6 | 15 | 14 | 35 | 1570 | 40.3 (34.7‐45.9) | 65.9% (59.9%‐75.4%) | 85.2% |
| Recurrent | 1 | 1 | 1 | 3 | 132 | 29.9 (21.2‐38.6) | 71.2% (52.4%‐89.9%) | 83.0% |
| Reirradiation | 1 | 1 | 0 | 2 | 57 | 18.6 (16.0‐21.4) | 77.9% (67.1%‐88.6%) | 0% |
| Post operation | 2 | 2 | 9 | 13 | 426 | 38.6 (28.8‐48.4) | 72.1% (62.2%‐82.1%) | 83.7% |
| Without operation | 6 | 11 | 4 | 21 | 938 | 40.4 (32.3‐48.5) | 61.6% (53.7%‐69.5%) | 79.4% |
| Received chemo. | 0 | 5 | 0 | 5 | 73 | 36.4 (21.3‐51.6) | 72.4% (59.8%‐85.0%) | 29.7% |
| Without chemo. | 1 | 0 | 2 | 3 | 119 | 29.8 (25.6‐34.0) | 67.6% (42.6%‐92.6%) | 89.8% |
| T4 | 2 | 4 | 3 | 9 | 507 | 36.6 (21.8‐51.3) | 60.3% (48.4%‐72.3%) | 83.0% |
| N0 | 4 | 5 | 4 | 13 | 789 | 35.5 (29.4‐41.8) | 67.0% (58.0%‐76.0%) | 82.5% |
| MM | 3 | 4 | 3 | 10 | 383 | 26.3 (19.0‐33.5) | 66.6% (53.7%‐79.4%) | 84.9% |
| SCC | 3 | 5 | 3 | 11 | 277 | 34.3 (26.2‐42.4) | 56.8% (46.6%‐66.9%) | 66.4% |
| ACC | 4 | 0 | 2 | 6 | 440 | 34.9 (21.1‐48.6) | 83.3% (71.9%‐94.6%) | 93.5% |
| ONB | 2 | 6 | 2 | 10 | 143 | 48.1 (34.0‐62.1) | 88.6% (81.2%‐96.1%) | 43.6% |
| UC | 1 | 0 | 3 | 4 | 42 | 37.3 (17.6‐53.4) | 64.4% (50.2%‐78.6%) | 0% |
| AC | 2 | 0 | 1 | 3 | 63 | 35.4 (21.3‐51.6) | 69.2% (45.1%‐93.2%) | 80.8% |
| Nasal cavity | 1 | 1 | 1 | 3 | 325 | 36.8 (22.9‐50.7) | 79.3% (70.6%‐87.9%) | 54.4% |
| Ethmoid sinus | 1 | 1 | 1 | 3 | 103 | 31.9 (22.6‐41.3) | 51.6% (7.9%‐95.4%) | 94.4% |
| Maxillary sinus | 1 | 1 | 1 | 3 | 154 | 31.4 (22.3‐40.4) | 73.2% (58.6%‐87.8%) | 65.2% |
| LC | ||||||||
| Naive | 6 | 10 | 11 | 27 | 1314 | 36.9 (30.6‐43.2) | 75.4% (70.4%‐80.4%) | 77.1% |
| Recurrent | 1 | 1 | 0 | 2 | 92 | 25.3 (20.1‐30.4) | 66.5% (3.7%‐129.3%) | 97.9% |
| Reirradiation | 1 | 1 | 0 | 2 | 57 | 18.6 (16.0‐21.4) | 55.2% (13.8%‐96.5%) | 91.9% |
| Post operation | 2 | 1 | 7 | 10 | 351 | 36.1 (25.1‐47.1) | 77.0% (68.6%‐82.1%) | 83.7% |
| Without operation | 6 | 7 | 4 | 17 | 874 | 37.1 (28.4‐45.9) | 67.7% (68.6%‐82.1%) | 82.0% |
| Received chemo. | 0 | 5 | 0 | 5 | 73 | 36.4 (21.3‐51.6) | 80.3% (70.8%‐89.8%) | 0% |
| Without chemo. | 1 | 0 | 2 | 3 | 119 | 30.0 (25.6‐34.4) | 64.9% (43.4%‐86.5%) | 81.9% |
| T4 | 2 | 3 | 1 | 6 | 443 | 37.7 (18.9‐56.6) | 65.2% (48.7%‐81.7%) | 88.8% |
| N0 | 4 | 3 | 3 | 10 | 730 | 34.6 (28.3‐41.0) | 78.1% (71.7%‐84.6%) | 62.2% |
| MM | 3 | 3 | 1 | 7 | 354 | 26.1 (18.4‐33.7) | 81.4% (73.8%‐88.9%) | 58.2% |
| SCC | 3 | 4 | 1 | 8 | 220 | 32.6 (22.4‐42.7) | 61.9% (49.0%‐74.7%) | 74.9% |
| ACC | 4 | 0 | 1 | 5 | 393 | 34.6 (18.6‐50.6) | 84.1% (80.1%‐88.1%) | 14.9% |
| ONB | 2 | 2 | 2 | 6 | 79 | 35.3 (21.5‐49.1) | 90.3% (83.2%‐97.5%) | 0% |
| UC | 1 | 0 | 2 | 3 | 44 | 24.0 (22.4‐25.7) | 73.5% (60.6%‐86.4%) | 0% |
| AC | 2 | 0 | 0 | 2 | 43 | 39.2 (11.0‐67.5) | 77.4% (64.9%‐89.9%) | 0% |
| Nasal cavity | 1 | 0 | 1 | 2 | 299 | 32.7 (17.3‐48.2) | 86.1% (79.1%‐93.1%) | 50.2% |
| Ethmoid sinus | 1 | 1 | 1 | 3 | 103 | 31.9 (22.6‐41.3) | 61.1% (26.9%‐95.4%) | 89.9% |
| Maxillary sinus | 1 | 1 | 1 | 3 | 154 | 31.4 (22.3‐40.4) | 81.7% (75.6%‐87.8%) | 0% |
Abbreviations: AC, adenocarcinoma; ACC, adenoid cystic carcinoma; Chemo., Chemotherapy; CI, confidence interval; CIRT, carbon ion radiation therapy; IMRT, intensity‐modulated radiation therapy; LC, local control; MM, mucosal melanoma; ONB, olfactory neuroblastoma; OS, overall survival; PRT, proton radiation therapy; SCC, squamous cell carcinoma; UC, undifferentiated carcinoma.