Table 2 SBRT dose constraints. (TD = Target dose)
Constraint | Per-Protocol | Minor Variation | Major Variation |
|---|---|---|---|
CTVsbrt D98a | > 100% TD | 95–100% TD | < 95% TD |
PTVsbrt D50a | < 105% TD | 105–110% TD | > 110% TD |
PTVsbrt D90a | > 100% TD | 95–100% TD | < 95% TD |
PTVsbrt D95a | > 95% TD | 90–95% TD | < 90% TD |
PTVsbrt D99a | > 16 Gy | 15–16 Gy | < 15 Gy |
PTVsbrt Dmax to 0.1cc | < 110% TD | 110–120% TD | > 120% TD |
PTVsbrt Dmax | Not within a critical structure | ||
Rectal Wall Dmax to 0.1cc | < 17 Gy | 17–17.5 Gy | > 17.5 Gy |
Rectal Wall V16 Gy | < 0.5cc | 0.5-1cc | > 1cc |
Rectal Wall V14 Gy | < 3cc | 3-5 cc | > 5cc |
Rectal Wall V12 Gy | < 30% | 30–40% | > 40% |
Rectal Wall V10 Gy | < 40% | 40–50% | > 50% |
Rectal Wall V8 Gy | < 60% | 60–70% | > 70% |
Rectal Mucosa Dmax to 0.1cc | < 15 Gy | 15–15.5 Gy | > 15.5 Gy |
Rectal Mucosa V14 Gy | < 0.5cc | 0.5-1cc | > 1cc |
Rectum Posterior Wall | < 8.5 Gy | 8.5–9.5 Gy | > 9.5 Gy |
Bladder Dmax to 0.1cc | < 110% TD | 110–120% TD | > 120% TD |
Bladder V19 Gy | < 10cc | 10-15cc | > 15cc |
Bladder V17 Gy | < 15% | 15–20% | > 20% |
Bladder V9 Gy | < 50% | 50–60% | > 60% |
Urethra PRV Dmax to 0.1cc | < 110% TD | 110–115% TD | > 115% TD |
Urethra PRV V105% TD | < 5% | 5–15% | > 15% |
Neck of Femurs Dmax to 0.1cc | < 8 Gy | 8–9 Gy | 9 Gy |
Penile Bulb Dmax to 0.1cc (Recommended) | 100% TD | 100–105% TD | > 105% TD |
Penile Bulb V10 Gy (Recommended) | <3cc | 3-5cc | > 5cc |
Intermediate Dose Spillage: ratio of volumes receiving 50% TD to 100% TD | < 4 | 4–5 | > 5 |
Total Monitor Units | < 3× Dose in cGy | 3–3.5× Dose in cGy | > 3.5× Dose in cGy |
High Dose Conformation: Volume receiving 100% of TD divided by volume of PTVsbrt | < 1.1 | 1.1–1.2 | > 1.2 |