Dose Constraints to Ribs in Lung SBRT

Primary Dose-Volume Constraints

The American Society of Radiation Oncology recommends limiting the chest wall volume receiving ≥30 Gy to <30 cm³ to keep the risk of severe chest wall pain and rib fracture below 30%, and restricting the maximum dose to 2 cm³ of any individual rib (D2cc) to <27 Gy in 3 fractions (or equivalent doses for other fractionation schemes) 1
The American Society of Radiation Oncology suggests that for 3-fraction regimens, limiting D2cc (dose to 2 cm³) of any rib to <27 Gy (equivalent to 3 × 9 Gy) corresponds to approximately 5% fracture risk 1

The American Society of Radiation Oncology recommends that for 54-60 Gy in 3 fractions, D2cc <27 Gy (3 × 9 Gy) maintains <5% fracture risk 1