Table 1.
Patient characteristics and RT treatment factors.
| Characteristics | VMAT (n = 70) | HT (n = 38) | p-Value |
|---|---|---|---|
| Lumpectomy: N (%) | 35 (50%) | 23 (60.5%) | 0.30 |
| Mastectomy: N (%) | 35 (50%) | 15 (39.5%) | |
| RT total dose (Gy) (SD) (range) |
56.4 (6.6) (40–74) |
56.5 (5.4) (45–70) |
0.97 |
| Number of fractions (SD) (range) |
28.7 (4.6) (15–37) |
28.8 (4.1) (16–35) |
0.92 |
| RT total dose EQD2 (Gy) | 57.1 | 57.8 | 0.77 |
| Conventional fractionation: N (%) Hypofractionation: N (%) |
63 (90%) 7 (10%) |
34 (89.5%) 4 (10.5%) |
1 |
| CTV (mL) (SD) (range) |
481.7 (263.8) (158.5–1314.4) |
532.3 (383.5) (150.4–1845.6) |
0.42 |
| PTV (mL) (SD) (range) |
974.3 (382.1) (402.2–2137.8) |
1058.8 (544.2) (388.9–2937.1) |
0.35 |
| RT target volume | 0.44 | ||
| Breast_ SCF | 21 (30%) | 10 (26.3%) | |
| Breast_ SCF_IMN | 14 (20%) | 13 (34.2%) | |
| Chest wall CW_ SCF | 10 (14.3%) | 4 (10.5%) | |
| Chest wall CW_ SCF_IMN | 25 (35.7%) | 11 (28.9%) | |
| RNI volume | 0.45 | ||
| IMN uninvolved | 31 (44.3%) | 14 (36.8%) | |
| IMN involved | 39 (55.7%) | 24 (63.2%) |
Abbreviations: VMAT—volumetric-modulated arc therapy; HT—helical tomotherapy; RT—radiotherapy; Gy—Gray; SD—standard deviation; EQD2—equivalent dose in 2 Gy fractions; CTV—clinical tumor volume; PTV—planning target volume; SCF—supraclavicular fossa; IMN—internal mammary nodes; CW—chest wall; RNI—regional nodal irradiation.