| Schedule | Constraint | Source |
|---|---|---|
| All schedules 40.05 Gy/15 fx · 30 Gy/5 fx · 26 Gy/5 fx | V95% ≤25% (ideal), ≤40% (acceptable) | ASTRO PBI 2023 |
| V50% ≤50% (ideal), ≤60% (acceptable) | ASTRO PBI 2023 |
Ipsilateral breast tissue minus PTV.
Quoted from eviQ 3658, checked 2026-09-23. Full table with references →
The rest of the treated breast outside the partial breast target.
The point of partial breast irradiation is to treat only the tumor bed region and spare the rest of the breast. How much of the remaining breast receives high and intermediate dose is therefore the measure of whether the technique is doing its job — which is why partial breast guidelines limit it with Vx metrics expressed as a percentage of the prescription.
It is defined as the ipsilateral breast tissue minus the PTV. The whole-breast contour itself comes from the breast atlases below.
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.
ESTRO consensus on target volume delineation for elective breast and nodal radiotherapy, with a version 1.1 correction published in 2016. Citation as given in the eviQ reference list; not yet checked against the journal.