| Freedman 200627 | 131 | Case-control retrospective study | F-IMRT 2D-RT | 46–50 Gy in 23–25 fractions + boost 10–16 Gy | Breast size was grouped as small (34 A, B; 36 A), medium (34 C; 36 B, C; 38A, B, C), or large (any D or size ≥ 40) | CTCAE v. 3.0 | 30 (IMRT) 28 (2D-RT) | 70 (IMRT) 72 (2D-RT) | 0 (IMRT) 0 (2D-RT) | IMRT is associated with a decrease in severity of acute desquamation compared with a matched control group treated with conventional radiation therapy. |
| Harsolia, 200725 | 172 | Retrospective study | F-IMRT 2D-RT | CF median dose 45 Gy + 16 Gy boost | 1.326 (IMRT) 1.489 (2D-RT) Breast volume divided into groups: 1.000 cm3 (small), 1.000–1.599 cm3 (medium), 1.600 cm3 (large) | NCI CTC v. 2.0 | 41 (IMRT) 85 (2D-RT) | | 1 (IMRT) 6 (2D-RT) | Lower rates of ≥ G2 toxicity with IMRT regardless of breast size.≥ G2 clinical toxicities associated with larger irradiated breast sizes, on average (<1.000 cm3; vs. >1.600 cm3)No G3 acute toxicity with breast volume (<1.000 cm3) and 3% G3 skin reaction in patients with breast volumes 1.600 cm3. |
| Freedman 200910 | 804 | Retrospective study | F-IMRT 2D-RT | 46–50 Gy in 23–25 fractions + boost 10–18 Gy | Bra size, (at least 63% with small and medium sizes)Small (32; 34A, B; 36A), Medium (34C; 36B, C;38A, B, C); Large (any D or size 40+) | CTCAE v. 3.0 | 52 (IMRT) 75 (2D-RT) | More large-breasted patients in IMRT group.IMRT reduces the incidence of ≥ G2 dermatitis in women of all breast sizes. |
| Shah 201223 | 335 | Prospective study | IMRT 2D-RT IMRT: HF -inversely planned IMRT CF - forward planned IMRT | Median dose 45 Gy + boost 16 Gy or 42.56 Gy without a boost | 1.378 for the whole group | CTCAE v. 3.0 | 1 (CF-IMRT) 23 (HF-IMRT) 12 (2D-RT) | IMRT is associated with reduced toxicities compared with 2D radiotherapy. |
| Breast volume divided into groups: 1.000 cm3 (small), 1.000-1.599 cm3 (medium), 1.600 cm3 (large) | In large-breasted patients, CF-IMRT was associated with reduced acute toxicities, while HF-IMRT was not. |
| Hardee 201228 | 97 | Prospective study | H-IMRT 3D-CRT IMRT: hybrid IMRT using a mixture of 3D tangent fields and dynamic multileaf collimator (MLC) IMRT fields in a 2:1 ratio | 46 Gy in 23 fractions + 14-Gy boost or 42.72 Gy in 16 fractions; all in prone position | Breast size was classified as small (A cup, <750 cm3), medium (B-C cups, 750–1.499 cm3), and large (D cup or larger,≥ 1,500 cm3) | RTOG | 5.1% ≥ G2 | Hypofractionated breast radiotherapy is well tolerated when treating patients in the prone position, even among those with large breast volumes. Breast IMRT significantly improves dosimetry but yields only a modest but confirmed benefit in terms of toxicities. |
| De Langhe 201432 | 377 | Prospective study | Prone or supine position with INV-IMRT or prone with F-IMRT or prone position with DIBH (n = 22) or supine F-IMRT ± DIBH | 40.05 Gy in 15 fractions + boost 10 Gy in 4 fractions (90–75% of patients) or 50 Gy in 25 fractions for 65% of patients with bra cup size ≥ D | Breast size was classified A, B, C and ≥ D cup | CTCAE v. 3.0 | 57.3 (≥ G2) | CF, supine IMRT, concomitant hormone treatment, high BMI, large breast, smoking during treatment, and genetic variation (in MLH1 rs1800734): all were associated with ≥ G2 toxicity. |
