| Schedule | Constraint | Source |
|---|---|---|
| 40.05 Gy / 15 fx or 42.56 Gy / 16 fx | Mean <1.5 Gy (mandatory) | IMPORT HIGH |
| Mean <0.5 Gy (optimal) | IMPORT HIGH |
Keep as low as reasonably achievable, especially with VMAT or fields crossing the midline.
Quoted from eviQ 3650, checked 2026-09-23. Full table with references →
| Schedule | Constraint | Source |
|---|---|---|
| All schedules 40.05 Gy/15 fx · 30 Gy/5 fx · 26 Gy/5 fx | Dmax ≤3% (ideal), ≤5% (acceptable) | ASTRO PBI 2023 |
Quoted from eviQ 3658, checked 2026-09-23. Full table with references →
| Schedule | Constraint | Source |
|---|---|---|
| 50 Gy / 25 fx | V3 Gy <10% (ideal) | NSABP B-51 |
| V5 Gy <10% (acceptable) | NSABP B-51 |
Keep as low as reasonably achievable, especially with VMAT or fields crossing the midline.
Quoted from eviQ 1925, checked 2026-09-23. Full table with references →
| Schedule | Constraint | Source |
|---|---|---|
| 45–50 Gy / 25 fx 1.8–2 Gy per fraction | V3 Gy <10% (ideal) | NSABP B-51 |
| V5 Gy <10% (acceptable) | NSABP B-51 |
Keep as low as reasonably achievable, especially with VMAT or fields crossing the midline.
Quoted from eviQ 1924, checked 2026-09-23. Full table with references →
The breast tissue on the untreated side, sitting close to the midline where medial tangents and internal mammary fields exit.
The concern is a small but long-term risk of a second cancer, so contralateral breast dose is kept as low as reasonably achievable. Tangents usually keep it low; it rises with IMRT or VMAT arcs, internal mammary treatment and fields that cross the midline — the NSABP B-51 protocol offers guidance in those cases. Published limits are written as a mean dose, a low-dose Vx or a maximum dose as a percentage of the prescription.
Contour the palpable and visible breast tissue on the opposite side; wiring it at simulation (as suggested for post-mastectomy cases) makes the edges easier to see on CT. The RTOG breast atlas defines the breast as the glandular tissue visible on CT.
NRG Oncology's breast downloads page, which links the RTOG Breast Cancer Atlas for Radiation Therapy Planning, an NRG whole-breast radiation therapy template and the RADCOMP breast atlas.