Table 3.
Consensus statements regarding cumulative dose constraints
| Consensus agreed | SA/A, % | N, % | D/SD, % | Round agreed | Median | |
|---|---|---|---|---|---|---|
| 3.1 | There is insufficient evidence to suggest volumetric cumulative dose constraints for the lung due to the changes in anatomy and function of the lung after an initial course of radiation therapy. | 80 | 13.3 | 6.7 | R3 | A |
| 3.2 | For radical reirradiation, the desirable cumulative maximum point dose constraint to the esophagus is an EQD2 of 75 Gy, although up to 100 Gy is acceptable (using an α/β = 3); the volume of the esophagus getting 55 GY should be less than 35% (V55Gy <35%).12 | 86 | 7 | 7 | R2 | A |
| 3.3 | For radical reirradiation, the desirable cumulative maximum point dose constraint to the spinal cord is an EQD2 of 60 Gy (using α/β = 2), with a maximum EQD2 of 67.5 Gy (provided that the initial irradiation dose to the cord did not exceed 50 Gy).13 | 80 | 13 | 7 | R2 | A |
| 3.4 | For radical reirradiation, the desirable cumulative maximum dose (Dmax) constraint to the brachial plexus is an EQD2 of 80Gy (α/β = 2) and an acceptable cumulative Dmax is 95 Gy (if the interval between treatments is >2 years).14 | 80 | 0 | 20 | R2 | A |
| 3.5 | For radical reirradiation, the desirable cumulative maximum dose (Dmax) constraint to the aorta is an EQD2 of 115 Gy (α/β = 3). The desirable cumulative Dmax to the pulmonary artery is an EQD2 of 110 Gy.15,16 | 80 | 0 | 20 | R2 | A |
| 3.6 | There is a lack of information to guide reirradiation dose constraints for the skin and the heart, therefore the use of other guidelines (e.g., QUANTEC or SABR guidelines) and to keep the dose to these organs as low as reasonably achievable are recommended. | 100 | 0 | 0 | R2 | A |
Abbreviations: D/SD = disagree/strongly disagree; EQD2 = equieffective dose in 2 Gy/fraction; N = neutral; QUANTEC = quantitative analyses of normal tissue effects in the clinic; R2 = round 2; R3 = round 3; SA/A = strongly agree/agree.