Table 2.
Radiotherapy Characteristics and Associations With IR Pneumonitis
| Characteristic | No IR Pneumonitis | IR Pneumonitis | All Patients | P |
|---|---|---|---|---|
| RT Characteristic | N = 152 (81) | N = 36 (19) | N = 188 | |
| Any RT | ||||
| Yes | 111 (73) | 21 (58.3) | 132 (70.2) | |
| No | 41 (27) | 15 (41.7) | 56 (29.8) | .11 |
| RT Within 1 Year of Anti—PD-1 /PD-L1 Therapy | ||||
| Yes | 88 (57.9) | 16 (44.4) | 104 (55.3) | |
| No | 64 (42.1) | 20 (55.6) | 84 (44.7) | .19 |
| Any Chest RT | ||||
| Yes | 81 (53.3) | 19 (52.8) | 100 (53.2) | |
| No | 71 (46.7) | 17 (47.2) | 88 (46.8) | 1.00 |
| > 1 Course Chest RT | ||||
| Yes | 21 (13.8) | 5 (13.9) | 26 (13.8) | |
| No | 131 (86.2) | 31 (86.1) | 162 (86.2) | 1.00 |
| Chest RT Within 1 Year of/anti—PD-1 /PD-L1 Therapy | ||||
| Yes | 56 (36.8) | 12(33.3) | 68 (36.2) | |
| No | 96 (63.2) | 24 (66.7) | 120 (63.8) | .85 |
| > 1 Course Chest RT Within 1 Year of Anti—PD-1 /PD-L1 Therapy | ||||
| Yes | 8 (5.3) | 2 (5.6) | 10 (5.3) | |
| No | 144 (94.7) | 34 (94.4) | 178 (94.7) | 1.00 |
| Chest-RT Characteristic | N = 81 (81) | N = 19 (19) | N = 100 | |
| Chest RT indication | ||||
| Palliative | 28 (34.6) | 2(10.5) | 30 (30) | |
| Curative intent | 53 (65.4) | 17 (89.5) | 70 (70) | .051 |
| Chest RT Dose (Gy) | ||||
| Available | 65 | 19 | 84 | |
| Median | 60 | 60 | 60 | |
| Range | 20–70 | 20–66.6 | 20–70 | .46 |
| Radiation Dosimetric Parameter | N = 43 | N = 12 | N = 53 | |
| Mean lung dose (Gy) | 12.46 (0.6–20.8) | 12.4 (1.4–19.8) | 12.4 (0.6–20.8) | .72 |
| Lung V20a | 23 (1–36) | 20.5 (0–34) | 22 (0–36) | .79 |
| Any SBRT Chest RT | ||||
| Yes | 7 (8.6) | 2 (10.5) | 9(9) | |
| No | 74 (91.4) | 17 (89.5) | 91 (91) | .68 |
| Any IMRT/VMAT Chest RT | ||||
| Yes | 36 (44.4) | 10 (52.6) | 46 (46) | |
| No | 45 (55.6) | 9 (47.4) | 54 (54) | .61 |
| Any 2-D/3-D Conformai Chest RT | ||||
| Yes | 23 (28.4) | 6(31.6) | 29 (29) | |
| No | 58 (71.6) | 13 (68.4) | 71 (71) | .78 |
| Curative-Intent Chest-RT Characteristic | N = 53 (76) | N = 17 (24) | N = 70 | |
| Curative intent Chest RT Before Anti—PD-1 /PD-L1 | ||||
| Yes | 49 (92.5) | 16 (94.1) | 65 (92.9) | |
| No | 4(7.5) | 1 (5.9) | 5(7.1) | 1.00 |
| RT Dosimetric Parameter | N = 30 | N = 10 | N = 38 | |
| Mean lung dose (Gy) | 15.1 (2.8–20.8) | 12.8 (8.7–19.8) | 14.8 (2.8–20.8) | .62 |
| Lung V20 | 25.5 (2–36) | 22 (14–34) | 24 (2–36) | .78 |
Data are presented as n (%) unless otherwise indicated.
Abbreviations: 2-D = 2-dimensional; 3-D = 3-dimensional; curative intent = definitive, adjuvant, or consolidative radiation; IMRT = intensity-modulated radiotherapy; IR = immune related; PD-I = programmed cell death I receptor; PD-L1 = programmed cell death ligand 1; RT = radiotherapy; SBRT = stereotactic body radiotherapy; VMAT = volumetric modulated arc therapy; V20 = percentage lung volume receiving 20 Gy.
a
Three patients in no-IR pneumonitis group had mean lung dose available, but did not have V20 available.