Table 2.
Difference in Clinical Characteristics and Dosimetry Between IMRT and 3D-CRT Groups
| RT Techniques | p value | ||
|---|---|---|---|
| 3DRT | IMRT | ||
| Patients | 134 (100%) | 174 (100%) | |
| BMI | 0.756 | ||
| ≤24 | 64 (47.8%) | 80 (46.0%) | |
| >24 | 70 (52.2%) | 94 (54.0%) | |
| Surgery type | 0.140 | ||
| BCS | 89 (66.4%) | 129 (74.1%) | |
| Mastectomy | 45 (33.6%) | 45 (25.9%) | |
| Nodal irradiation | 0.885 | ||
| No | 79 (59.0%) | 104 (59.8%) | |
| Yes | 55 (41.0%) | 70 (40.2%) | |
| Skin toxicity | <0.001* | ||
| < grade 2 | 99 (73.9%) | 156 (89.7%) | |
| ≥ grade 2 | 35 (26.1%) | 18 (10.3%) | |
| Dosimetry (mean±SD) | |||
| CTV-V95% | 98.6±0.1% | 99±0.1% | 0.009* |
| PTV-V95% | 94.5±0.2% | 95.2±0.1% | 0.001* |
| TV-V105% | 7.8±0.5% | 2.9±0.2% | <0.001* |
| <5.7% | 53 (39.6%) | 151 (86.8%) | <0.001* |
| ≥5.7% | 81 (60.4%) | 23 (13.2%) | |
| TV-V107% | 1.2±0.2% | 0.2±0.03% | <0.001* |
| <1% | 90 (67.2%) | 152 (87.4%) | 0.001* |
| ≥1% | 44 (32.8%) | 22 (12.6%) | |
Notes: *Statistical significance. V105% and V107%=percent volume receiving 105% and 107% of the prescribed dose.
Abbreviations: BCS, breast-conserving surgery; BMI, body mass index; TV, treatment volume.