Table 3.
IR Pneumonitis and IR Pneumonitis Radiographic Features in Relation to RT Fields
| Characteristic | Value |
|---|---|
| IR Pneumonitis (CTCAE grade) | n (%) |
| All grades | 36 (100) |
| Grade 2 | 14 (38.9) |
| Grade 3 | 14 (38.9) |
| Grade 4 | 2 (5.6) |
| Grade 5 | 5 (13.9) |
| Unknown | 1 (2.8) |
| IR Pneumonitis Radiographic Features With Overlaid Chest RT Plans | N = 13 |
| Chest RT Indication | |
| Palliative intent (20–30 Gy) | 2(15) |
| Curative intent (52.5–66 Gy) | 11 (85) |
| Predominant IR Pneumonitis Feature | |
| Moderate to marked GGO | 7(54) |
| Minimal to mild GGO | 3 (23) |
| Organizing pneumonia | 2(15) |
| Centrilobular tree-in-bud nodularity | 1 (8) |
| Predominant Location of IR Pneumonitis Feature in Relation to Chest-RT Dose Regionsa | |
| High-dose RT | 0 |
| Intermediate-dose RT | 1 (8) |
| Low-dose RT | 5 (38) |
| Outside RT dose fall-off region | 7(58) |
High dose, > 45 Gy; intermediate dose, > 20 Gy and < 45 Gy; low dose, < 20 Gy; outside RT fall-off region, < 1 Gy.
Abbreviations: CT = computed tomography; CTCAE = Common Terminology Criteria for Adverse Events version 4.0; Curative intent = definitive, adjuvant, or consolidative radiation; GGO = ground-glass opacity; IR = immune related; RT = radiotherapy.
a
One patient with minimal GGO pattern of IR pneumonitis was not categorized in relation to radiation dose zones, given minimal radiographic extent. One patient had GGOs equally distributed between low RT dose region and beyond RT dose fall-off region.