Patient characteristics
| Level | Overall | GR | Erlangen | Ghent | P value | |
| n | 94 | 38 | 16 | 40 | ||
| Age (median(IQR)) | 60.38 (50.68 to 69.04) | 57.38 (48.75 to 67.77) | 64.04 (55.84 to 69.12) | 62.80 (50.28 to 71.36) | 0.320 | |
| Sex (%) | F | 26 (27.7) | 14 (36.8) | 2 (12.5) | 10 (25.0) | 0.179 |
| M | 68 (72.3) | 24 (63.2) | 14 (87.5) | 30 (75.0) | ||
| Performance status (%) | 0 | 53 (56.4) | 18 (47.4) | 0 (0.0) | 35 (87.5) | <0.001 |
| 1 | 24 (25.5) | 19 (50.0) | 0 (0.0) | 5 (12.5) | ||
| 2 | 1 (1.1) | 1 (2.6) | 0 (0.0) | 0 (0.0) | ||
| NA | 16 (17.0) | 0 (0.0) | 16 (100.0) | 0 (0.0) | ||
| Histology (%) | CRC adenocarcinoma | 21 (22.3) | 21 (55.3) | 0 (0.0) | 0 (0.0) | NA |
| HNSCC | 5 (5.3) | 0 (0.0) | 5 (31.2) | 0 (0.0) | ||
| Melanoma | 39 (41.5) | 14 (36.8) | 0 (0.0) | 25 (62.5) | ||
| NSCLC | 14 (14.9) | 3 (7.9) | 11 (68.8) | 0 (0.0) | ||
| TCC | 13 (13.8) | 0 (0.0) | 0 (0.0) | 13 (32.5) | ||
| Unknown primary | 2 (2.1) | 0 (0.0) | 0 (0.0) | 2 (5.0) | ||
| Number of prior lines of therapy (median(IQR)) | 1.00 (0.00 to 1.00) | 1.00 (1.00 to 2.00) | NA (NA, NA) | 0.00 (0.00 to 1.00) | <0.001 | |
| CT interval (median(IQR)) | 85.50 (61.75 to 103.75) | 63.00 (44.25 to 89.75) | 128.00 (106.25 to 141.00) | 83.50 (69.75 to 102.00) | <0.001 | |
| N of VOI at baseline (median(IQR)) | 3.00 (2.00 to 4.00) | 3.00 (2.00 to 4.00) | 3.00 (3.00 to 4.25) | 3.00 (2.00 to 3.00) | 0.089 | |
| N of VOI of irradiated lesions at baseline (median(IQR)) | 1.00 (1.00 to 1.00) | 1.00 (1.00 to 1.00) | 1.00 (1.00 to 2.00) | 1.00 (1.00 to 1.00) | 0.012 | |
| N of VOI of non-irradiated lesions at baseline (median(IQR)) | 2.00 (1.00 to 3.00) | 2.00 (1.00 to 3.00) | 2.50 (1.00 to 3.00) | 2.00 (1.00 to 2.00) | 0.583 | |
| N of organs involved (%) | < or =2 | 56 (59.6) | 20 (52.6) | 3 (18.8) | 33 (82.5) | <0.001 |
| > or =3 | 38 (40.4) | 18 (47.4) | 13 (81.2) | 7 (17.5) | ||
| IO therapy (%) | Atezolizumab | 24 (25.5) | 24 (63.2) | 0 (0.0) | 0 (0.0) | |
| Ipilimumab | 25 (26.6) | 14 (36.8) | 0 (0.0) | 11 (27.5) | ||
| Nivolumab | 29 (30.9) | 0 (0.0) | 13 (81.2) | 16 (40.0) | ||
| Pembro | 16 (17.0) | 0 (0.0) | 3 (18.8) | 13 (32.5) | ||
| N of IO cycles (median(IQR)) | 4.00 (3.00 to 10.00) | 4.00 (3.00 to 6.00) | 3.00 (0.00 to 12.00) | 5.50 (4.00 to 16.00) | ||
| Time between RT and IO therapy (%) | < or =14 days | 35 (37.2) | 0 (0.0) | 14 (87.5) | 21 (52.5) | |
| > day 14 | 59 (62.8) | 38 (100.0) | 2 (12.5) | 19 (47.5) | ||
| Hypofractionated RT (%) | 0 | 3 (3.2) | 0 (0.0) | 3 (18.8) | 0 (0.0) | |
| 1 | 91 (96.8) | 38 (100.0) | 13 (81.2) | 40 (100.0) | ||
| Stereotactic RT (%) | 0 | 7 (7.4) | 0 (0.0) | 7 (43.8) | 0 (0.0) | |
| 1 | 87 (92.6) | 38 (100.0) | 9 (56.2) | 40 (100.0) | ||
| RT: N of fractions (median(IQR)) | 3.00 (3.00 to 3.00) | 3.00 (3.00 to 3.00) | 12.00 (10.75 to 15.00) | 3.00 (3.00 to 3.00) | ||
| RT: dose per fraction (median(IQR)) | 8.00 (6.00 to 12.00) | 13.00 (5.00 to 15.00) | 3.50 (3.00 to 6.00) | 8.00 (8.00 to 8.00) | ||
| RT: total dose in EQD2 (median(IQR)) | 36.00 (36.00 to 69.00) | 75.00 (18.75 to 93.75) | 51.55 (41.25 to 70.00) | 36.00 (36.00 to 36.00) | ||
| Follow-up (median(IQR)) | 451.50 (256.50 to 633.75) | 360.50 (243.00 to 624.75) | 277.50 (187.50 to 394.25) | 540.00 (376.00–817.75) | ||
| PD-L1 (tumor cells) (median(IQR)) | 5.00 (0.00–33.75) | NA (NA, NA) | 30.00 (12.50–80.00) | 1.00 (0.00–10.00) | ||
| PD-L1 (immune cells) (median(IQR)) | 5.00 (0.00–12.50) | NA (NA, NA) | 8.75 (5.00–17.50) | 1.00 (0.00–10.00) | ||
| Baseline absolute neutrophil count (%) | < or =7.5 G/L | 68 (72.3) | 27 (71.1) | 5 (31.2) | 36 (90.0) | |
| >7.5 G/L | 17 (18.1) | 11 (28.9) | 2 (12.5) | 4 (10.0) | ||
| NA | 9 (9.6) | 0 (0.0) | 9 (56.2) | 0 (0.0) | ||
| Baseline absolute lymphocyte count (%) | > or =1 G/L | 64 (68.1) | 30 (78.9) | 1 (6.2) | 33 (82.5) | |
| <1 G/L | 21 (22.3) | 8 (21.1) | 6 (37.5) | 7 (17.5) | ||
| NA | 9 (9.6) | 0 (0.0) | 9 (56.2) | 0 (0.0) | ||
| Baseline neutrophil-to-lymphocyte ratio (%) | < or =6 | 65 (69.1) | 29 (76.3) | 2 (12.5) | 34 (85.0) | |
| >6 | 20 (21.3) | 9 (23.7) | 5 (31.2) | 6 (15.0) | ||
| NA | 9 (9.6) | 0 (0.0) | 9 (56.2) | 0 (0.0) | ||
| Baseline LDH (%) | < or =250 | 56 (59.6) | 21 (55.3) | 6 (37.5) | 29 (72.5) | |
| >250 | 30 (31.9) | 17 (44.7) | 2 (12.5) | 11 (27.5) | ||
| NA | 8 (8.5) | 0 (0.0) | 8 (50.0) | 0 (0.0) | ||
| Baseline albumin (%) | > or =35 | 58 (61.7) | 32 (84.2) | 11 (68.8) | 15 (37.5) | |
| <35 | 6 (6.4) | 5 (13.2) | 1 (6.2) | 0 (0.0) | ||
| NA | 30 (31.9) | 1 (2.6) | 4 (25.0) | 25 (62.5) | ||
| Baseline CRP (%) | < or =10 mg/L | 58 (61.7) | 18 (47.4) | 9 (56.2) | 31 (77.5) | |
| >10 mg/L | 32 (34.0) | 20 (52.6) | 7 (43.8) | 5 (12.5) | ||
| NA | 4 (4.3) | 0 (0.0) | 0 (0.0) | 4 (10.0) | ||
| Baseline RMH score (%) | 0 | 23 (24.5) | 10 (26.3) | 0 (0.0) | 13 (32.5) | |
| 1 | 25 (26.6) | 18 (47.4) | 5 (31.2) | 2 (5.0) | ||
| 2 | 7 (7.4) | 6 (15.8) | 1 (6.2) | 0 (0.0) | ||
| 3 | 3 (3.2) | 3 (7.9) | 0 (0.0) | 0 (0.0) | ||
| NA | 36 (38.3) | 1 (2.6) | 10 (62.5) | 25 (62.5) | ||
| Baseline GR immune score (%) | Low | 26 (27.7) | 16 (42.1) | 0 (0.0) | 10 (25.0) | |
| High | 29 (30.9) | 21 (55.3) | 3 (18.8) | 5 (12.5) | ||
| NA | 39 (41.5) | 1 (2.6) | 13 (81.2) | 25 (62.5) | ||
CRC, colorectal cancer; CRP, C reactive protein; EQD2, equivalent dose in 2 Gy fraction; GR, Gustave Roussy ; HNSCC, squamous cell cancers of the head and neck; IO, immuno-oncology; LDH, lactate dehydrogenase; NA, not available; NSCLC, non-small cell lung cancer; PD-L1, programmed death-ligand 1; RMH, Royal Marsden Hospital score; RT, radiotherapy; TCC, Transitional cell carcinoma; VOI, volume of interest.