Table 2.
Consensus protocol for five-fraction MR-guided SBRT for pancreas. Target objectives are subject to concession if OAR constraints cannot be met. There is no specific maximum dose limit to the GTV.
| Parameter | Value |
|---|---|
| Prescription dose (#fractions x dose) | 5x10 Gy |
| GTV | V100% >95 % |
| PTV | V95% >95 % |
| Duodenum, large bowel, stomach | D0.5 cc < 35 Gy |
| Small bowel | D0.5 cc < 40 Gy |
| Biliary duct | D0.1 cc < 50 Gy |
| Large vessels (aorta, inferior vena cava) | D0.1 cc < 53 Gy |
| Superior mesenteric artery | D0.1 cc < 53 Gy |
| Celiac trunk | D0.1 cc < 53 Gy |
| Kidneys | Dmean < 10 Gy; D67% < 16.8 Gy |
| Spinal cord | D0.1 cc < 28 Gy |
| GTV-PTV margin | 2 mm with active motion management |
| Number of beams | 9–14 |
| Number of segments | As low as reasonably possible (lower limit = 45) |
| Passive motion management | Abdominal compression |
| Arms position | Arms down |