Table 4. .
Most frequent late radiation effects of radiotherapy in childhood NPC, and impact of the IMRT use
| All grades (2D–3D CRT) |
All grades (IMRT) | Grade 3–4 (2D–3D CRT) |
Grade 3–4 (IMRT) |
Positive impact of IMRT vs 2D–3D CRT on late effect incidence | |
| Hearing loss | 40–54%1,12,27 | 22–50%1,27,45 | 5–10%12,27 | 027 | Yes1 No27 |
| Xerostomia | 52–97%1,74 | 34–48%1,45 | 0%27 | 0%27 | Yes1,27 |
| Neck fibrosis | 34–94%1,27 | 22–85%1,27,35 | 7–19%27,74) | 9%27 | Yes1 No27 |
| Hypothyroidism | 3–52%27,64,74 | 0–50%27,45 | 0% (27,80) | 0%27 | No1,27 |
| Growth retardation | 4–17%1,12 | 2–20%62,71 | NR | NR | No (1,45,80) |
| Trismus | 15–56%1,27,74 | <10%62,71 | 8%27 | 5%27 | Yes27 No1 |
| Caries | 22%4 | 2%7 | NR | NR | NR |
CRT, conformational radiation therapy; IMRT, intensity modulated radiation therapy; NPC, nasopharyngeal carcinoma; NR, not reported; positive impact, significative or trend (p < 0.