Scenario Scenario A: Leaf moved forward from LP1 to LP2, then moved forward from LP2 to LP3. | LP1 (cm) | LP2 (cm) | LP3 (cm) | LP1-2 Speed (cm/s) | LP 2-3 Speed (cm/s) |
---|---|---|---|---|---|
A (ori) | 4.6 | 5.4 | 5.9 | 1.8 | 1.1 |
A (mod) | 4.6 | 5.6 | 5.9 | ||
B (ori) | 4.6 | 5.4 | 4.9 | 1.8 | −1.1 |
B (mod) | 4.6 | 5.6 | 4.9 |
Case | ∆ Negative sign means dose of ‘standard’ plan is lower than that of ‘slowing MLC’ plan CP = control point | ∆ Negative sign means dose of ‘standard’ plan is lower than that of ‘slowing MLC’ plan CP = control point | Total leave states per arc (leaves on both banks/CP)×(CP) | Average modified MLC leaves (%) | Average faster moving leaves (%) |
---|---|---|---|---|---|
A1 | −0.8 | −0.2 | 120 × 178 | 1.7 | 56.5 |
A2 | −0.9 | −0.3 | 120 × 178 | 1.6 | 53.6 |
A3 | −1.2 | −0.5 | 120 × 178 | 1.7 | 51.3 |
A4 | 120 × 178 | ||||
A5 | −1.1 | −0.3 | 120 × 178 | 1.7 | 52.7 |
Case P: Prostate VMAT cases; B: Brain VMAT cases; A: Anal VMAT cases. | Dose Prescription (Gy/fx × fx) | Gantry speed (deg/s) | LTMCS Leaf travel and modulation complexity score (LTMCS) for a VMAT plan. LTMCS ranges from 0 to 1. Low LTMCS indicates high modulation complexity. | Arc | Maximal MLC leaf speed range along 178 CPs (cm/s) | Range of Leaf Position Changes along 178 CPs (mm) | Total Modified MLC leaves % |
---|---|---|---|---|---|---|---|
P1 | 2.0 × 33 | 4.8 | 0.164 | 1 | 1.87-1.92 | −1.90-1.88 | 1.5 |
P2 | 2.0 × 33 | 4.8 | 0.262 | 1 | 1.87-1.90 | −1.90-2.00 | 1.6 |
2 | 1.87-1.90 | −1.90-2.00 | 1.6 | ||||
P3 | 2.0 × 33 | 4.8 | 0.163 | 1 | 1.87-1.90 | −1.90-2.00 | 1.5 |
2 | 1.87-1.90 | −1.90-2.00 | 1.6 | ||||
B1 | 1.8 × 33 | 4.8 | 0.204 | 1 | 1.87-1.92 | −1.88-1.90 | 1.6 |
B2 | 1.8 × 33 | 4.8 | 0.199 | 1 | 1.87-1.92 | −1.88-1.90 | 1.5 |
2 | 1.87-1.92 | −1.88-1.90 | 1.7 | ||||
B3 | 1.8 × 33 | 4.8 | 0.217 | 1 | 1.85-1.90 | −1.88-2.00 | 1.5 |
2 | 1.85-1.90 | −1.88-2.00 | 1.6 | ||||
A1 | 1.8 × 33 | 4.8 | 0.081 | 1 | 1.90-1.92 | −1.80-1.80 | 1.7 |
2 | 1.90-1.92 | −1.80-1.80 | 1.7 | ||||
3 | 1.90-1.92 | −1.80-1.80 | 1.7 | ||||
4 | 1.90-1.92 | −1.80-1.80 | 1.8 | ||||
A2 | 1.8 × 33 | 4.8 | 0.083 | 1 | 1.92-1.95 | −1.87-1.87 | 1.5 |
2 | 1.92-1.95 | −1.87-1.87 | 1.6 | ||||
3 | 1.92-1.95 | −1.87-1.87 | 1.6 | ||||
4 | 1.92-1.95 | −1.87-1.87 | 1.5 | ||||
A3 | 1.8 × 33 | 4.8 | 0.105 | 1 | 1.92-1.95 | −1.87-1.87 | 1.7 |
2 | 1.92-1.95 | −1.87-1.87 | 1.7 | ||||
3 | 1.92-1.95 | −1.87-1.87 | 1.7 | ||||
A4 | 1.8 × 33 | 4.8 | 0.076 | 1 | 1.87-1.90 | −1.80-1.93 | 2.2 |
2 | 1.87-1.90 | −1.80-1.93 | 2.2 | ||||
3 | 1.87-1.90 | −1.80-1.93 | 2.3 | ||||
4 | 1.87-1.90 | −1.80-1.93 | 2.3 | ||||
A5 | 1.8 × 33 | 4.8 | 0.084 | 1 | 1.90-1.92 | −1.80-1.80 | 1.7 |
2 | 1.90-1.92 | −1.80-1.80 | 1.7 | ||||
3 | 1.90-1.92 | −1.80-1.80 | 1.8 |