Table 2.
Consensus statements regarding radiation therapy planning technique
| Consensus agreed | SA/A, % | N, % | D/SD, % | Round agreed | Median | |
|---|---|---|---|---|---|---|
| 2.1 | When combining initial and reirradiation plans, either rigid or deformable dose registration are acceptable methods (although there are considerable uncertainties in either process, and additional investigation is warranted). | 80 | 6 | 14 | R2 | SA |
| 2.2 | 18-FDG-PET/CT is recommended to aid tumor volume delineation. | 86 | 7 | 7 | R2 | SA |
| 2.3 | When contouring for conventionally fractionated radical reirradiation, an acceptable minimum expansion from CTV to PTV is 5 mm (or follow institutional guidelines where available). | 86 | 7 | 7 | R2 | A |
| 2.4 | PTV coverage can be compromised to achieve acceptable OAR doses. | 80 | 6 | 14 | R2 | SA |
| 2.5 | Radical reirradiation should be performed using highly conformal radiation therapy techniques (e.g., VMAT, tomotherapy, CyberKnife). | 100 | 0 | 0 | R3 | SA |
| 2.6 | SABR is the preferred reirradiation technique where the tumor is not ultracentral, the tumor volume is small, and there is minimal overlap with OARs. | 80 | 13.3 | 6.7 | R2 | SA |
| 2.7 | Protons may have a role for reirradiation and requires further evaluation in the context of a clinical trial. | 80 | 20 | 0 | R3 | A |
| 2.8 | Acceptable doses for conventionally fractionated radical thoracic reirradiation are 60 Gy in 30 fractions or 55 Gy in 20 fractions once daily for non-small cell lung cancer. | 93 | 0 | 7 | R2 | A |
| 2.9 | Daily cone beam CT is recommended for treatment verification for conventionally fractionated reirradiation. | 100 | 0 | 0 | R2 | SA |
| 2.10 | Any dose and fractionation that can safely deliver a BED >100 Gy to the tumor is acceptable for radical reirradiation with SABR. | 86.7 | 0 | 13.3 | R3 | A |
| 2.11 | Daily cone beam CT is recommended for treatment verification for SABR reirradiation. | 100 | 0 | 0 | R2 | SA |
Abbreviations: BED = biologically effective dose; CT = computed tomography; CTV = clinical target volume; D/SD = disagree/strongly disagree; N = neutral; OAR = organ at risk; PTV = planning target volume; R2 = round 2; R3 = round 3; SA/A = strongly agree/agree; VMAT = volumetric arc therapy; 18-FDG-PET/CT = 18-fluorodeoxyglucose positron emission tomography/computed tomography.