Table 4.
Heart dose and target coverage with and without conformal shielding of the heart
| Heart | Breast PTVCT | |||||
| Mean dose (Gy) | Volume ≥ 30 Gy (%) | Volume receiving ≥ 95% of prescribed dose (%) | ||||
| 3D-CRT | 3D-CRT with shielded heart | 3D-CRT | 3D-CRT with shielded heart | 3D-CRT | 3D-CRT with shielded heart | |
| Patient | ||||||
| 1 | 4.8 | 2.0 | 5.1 | 0.0 | 98.9 | 93.8 |
| 2 | 2.9 | 2.1 | 1.4 | 0.0 | 98.9 | 97.5 |
| 3 | 3.4 | 2.0 | 2.5 | 0.0 | 99.1 | 90.3 |
Dosimetric results with and without deliberate multileaf collimator shielding of the heart in the tangential breast beams. Results based on cumulative dose plans (breast plan 50 Gy + boost plan 16 Gy). Patients had upper-quadrant tumor sites. Boost PTVCT target coverage was not compromised.
3D-CRT: three-dimensional conformal radiation therapy; PTV: planning target volume; PTVCT: computed tomography (CT)-based PTV.