Table 1.

PROMETHEUS SBRT dose constraints.

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 0.1 cc	<110% TD	110–120% TD	>120% TD
Rectal wall Dmax to 0.1 cc	<17 Gy	17–17.5 Gy	>17.5 Gy
Rectal wall V16 Gy	<0.5 cc	0.5–1 cc	>1 cc
Rectal wall V14 Gy	<3 cc	3–5 cc	>5 cc
Rectal wall V10 Gy	<40%	40–50%	>50%
Rectum posterior wall	<8.5 Gy	8.5–9.5 Gy	>9.5 Gy
Bladder Dmax to 0.1 cc	<110% TD	110–120% TD	>120% TD
Bladder V19 Gy	<10 cc	10–15 cc	>15 cc
Bladder V17 Gy	<15%	15–20%	>20%
Bladder V9 Gy	<50%	50–60%	>60%
Urethra PRV Dmax to 0.1 cc	<110% TD	110–115% TD	>115% TD
Urethra PRV V105% TD	<5%	5–15%	>15%
Femoral neck Dmax to 0.1 cc	<8 Gy	8–9 Gy	9 Gy
Penile bulb Dmax to 0.1 cc (recommended)	100% TD	100–105% TD	>105% TD
Penile bulb V10 Gy (recommended)	<3cc	3–5 cc	>5 cc
Intermediate dose spillage: ratio of volumes receiving 50% TD to 100% TD	<4	4–5	>5
High dose conformation: V100% TD/PTVsbrt volume	<1.1	1.1–1.2	>1.2
Total monitor units	<3 × Dose in cGy	3–3.5 × Dose in cGy	>3.5 × Dose in cGy

TD, Target dose (19 or 20 Gy).

^athese volumes may exclude the urethra PRV.