Table 3.
Detailed dosimetric analysis of individual and cumulative radiation courses
| Initial radiation therapy |
Reirradiation/cumulative radiation therapy |
||
|---|---|---|---|
| Organ at risk |
Median value (range) |
Organ at risk |
Median value (range) |
| Conventional fractionation | 10-fraction reirradiation | ||
| Total lung | Total lung | ||
| MLD (Gy) | 18.5 (3.3-22.4) | MLD (Gy) | 17.7 (10.5-21.2) |
| V5 (%) | 57.1 (14.1-87.2) | V5 (%) | 13.8 (10.5-21.8) |
| V20 (%) | 27.3 (4.4-41.7) | V20 (%) | 5.9 (2.2-11.7) |
| V40 (%) | 15.3 (1.2-22.97) | V40 (%) | 2.0 (0.6-4.2) |
| Esophagus | Esophagus | ||
| Dmax (Gy) | 63.8 (33.8-100.1) | Dmax (Gy) | 12.6 (10.3-26.9) |
| D5cc (Gy) | 54.3 (17.1-81.5) | V20 (cc) | 0 (0-1.56) |
| D10cc (Gy) | 32.0 (1.81-75.7) | V40 (cc) | 0 (0-0) |
| Proximal bronchial tree | Proximal bronchial tree | ||
| Dmax (Gy) | 65.2 (24.9-109.7) | Dmax (Gy) | 10.2 (3.18-46.6) |
| D5cc (Gy) | 62.7 (17.7-100.5) | V30 (cc) | 0 (0-0.4) |
| D10cc (Gy) | 61.5 (12.8-97.0) | V50 (cc) | 0 (0-0) |
| Great vessels | Great vessels | ||
| Dmax (Gy) | 66.4 (52.7-109.2) | Dmax (Gy) | 39.9 (9.4-86.2) |
| D5cc (Gy) | 64.9 (51.0-105.0) | V50 (cc) | 7.6 (0-31.8) |
| D10cc (Gy) | 64.7 (50.6-102.6) | ||
| SBRT | Cumulative radiation therapy (EQD2, α/β = 3) | ||
| Total lung | Total lung | ||
| MLD (Gy) | 6.67 (2.4-19.3) | MLD (Gy) | 23.7 (10.1-32.9) |
| V5 (%) | 19.7 (9.0-83.1) | V5 (%) | 64.5 (22.3-99.1) |
| V20 (%) | 7.9 (0.6-20.1) | V20 (%) | 33.1 (11.0-51.2) |
| V40 (%) | 2.3 (0-6.0) | V40 (%) | 19.8 (7.1-29.6) |
| Esophagus | Esophagus | ||
| Dmax (Gy) | 28.2 (7.0-44.8) | Dmax (Gy) | 93.2 (49.7-148.0) |
| V20 (cc) | 1.6 (0-8.6) | D5cc (Gy) | 52.8 (19.2-111.5) |
| V40 (cc) | 0 (0-6.6) | D10cc (Gy) | 41. 7 (1.7-88.5) |
| Proximal bronchial tree | Primary bronchial tree | ||
| Dmax (Gy) | 62.4 (30.0-88.3) | Dmax (Gy) | 163.3 (76.8-203.8) |
| V30 (cc) | 4.4 (0-12.1) | D5cc (Gy) | 102.1 (45.5-167.0) |
| V50 (cc) | 0.8 (0-5.9) | D10cc (Gy) | 63.3 (14.3-130.2) |
| Great vessels | Great vessels | ||
| Dmax (Gy) | 74.9 (54.6-86.5) | Dmax (Gy) | 191. 2 (129.1-262.1) |
| V50 (cc) | 4.2 (0.1-21.3) | D5cc (Gy) | 138.9 (70.0-186.8) |
| D10cc (Gy) | 112.8 (60.9-175.3) | ||
Abbreviations: Dmax = maximum dose; EQD2 = equivalent total doses in 2 Gy fractions; MLD = mean lung dose; SBRT = stereotactic body radiation therapy; V5 = volume receiving 5 Gy; V20 = volume receiving 20 Gy; V40 = volume receiving 40 Gy; D5cc = dose to 5 cc volume; D10cc = dose to 10 cc volume.