Table 4.
Multivariate Cox model for OS using whole heart V55 as a single DVH index representing heart dosimetry. V55 represents percentage of whole heart volume receiving dose 55 Gy, or greater. The Hazard Ratio for cardiac toxicity can be calculated as HRcardiac = e0.043*V55 ≅ (1.044)V55. Equations and examples needed to calculate an individualized HR for OS using a specific patient’s variables are provided in the Supplement.
| Model | Heart V55 |
|
|---|---|---|
| HR | P-value | |
| VD (per 1%) | 1.044 | 0.03 |
| Age (per year) | 1.04 | 0.01 |
| Stage IIIB | 1.78 | 0.02 |
| Chemotherapy (Concurrent or Sequential) | 0.46 | 0.04 |