ESTRO 2024 - Abstract Book

S3540

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2024

PTV V 30Gy (%)

96.09 (93.67, 98.77)

96.03 (95.11, 97.48)

98.33 (97.54, 99.51)

<0.001 0.06

(-0.61,

-2.23 (-2.75, - 1.71) [0.000]

2.29 (-2.61, -1.98) [0.000]

0.73) [1.000]

IPCI

1.17

1.10 (1.03, 1.19)

1.06 (1.03, 1.09)

<0.001 0.07 (0.05, 0.10) [0.002]

0.12 (0.09, 0.14) [0.000]

0.04 (0.02, 0.06) [0.081]

(1.07,

1.35)

GI

3.34

2.88 (2.61, 3.32)

3.14 (2.85, 3.59)

<0.001 0.46 (0.31, 0.61) [0.000]

0.20 (0.31, 0.61) [0.399]

-0.26 (0.35, -0.17) [0.001]

(2.82,

3.98)

HI

0.25

0.22 (0.14, 0.28)

0.13 (0.09, 0.18)

<0.001 0.03 (0.01, 0.06) [0.342]

0.13 (0.10, 0.15) [0.000]

0.09 (0.08 to 0.11) [0.000]

(0.12,

0.35)

Spinal cord D 0.03cc (Gy)

22.28 (0.01, 26.65) 19.25 (0.01, 21.98)

21.15 (0.01, 25.09)

22.27 (0.00, 26.31)

0.004

0.01

(-0.34,

-1.12 (-1.66, - 0.58) [0.027]

1.13 (0.53, 1.74) [0.006]

0.36) [1.000]

17.17 (0.01, 21.14)

18.36 (0.00, 21.69)

<0.001 2.08 (1.50, 2.66) [0.000]

0.90 (0.33, 1.46) [0.010]

-1.19 (-1.72, - 0.65) [0.043]

D 0.35cc (Gy)

All Eclipse™ and Element® plans were met the PTVs passing criteria, but only 90% of Precision® plans achieved the PTV objective (Table 1). Eclipse™ exhibited significantly higher PTV V30Gy than both Precision® and Elements® (p = 0.000). Eclipse™ and Elements® plans achieved better dose gradient from the PTVs to the spinal cord surface compared to Precision® (Precision®-Elements®: p = 0.001, Precision®-Eclipse™: p = 0.000). There was no significant difference dose gradient between Eclipse™ and Elements® (p = 0.618).

Precision® plans showed the lowest conformity compared to Eclipse™ and Elements® plans (IPCI: Precision®- Elements® p = 0.002, Precision®-Eclipse™ p = 0.000).

Precision® and Elements® plans showed greater dose heterogeneity than Eclipse™ plans (HI: Precision®-Eclipse™ p = 0.000, Elements®-Eclipse™ p = 0.000).

Elements® plans exhibited a steeper dose fall-off than other plans (GI: Precision®-Elements® p = 0.000, Elements®-Eclipse™ p = 0.001).

Elements® plans achieved the lowest to the spinal cord than Precision® (D0.03cc: p = 0.006 and D0.35cc: p = 0.000) and Eclipse™ (D0.03cc: p = 0.027 and D0.35cc: p = 0.043). Doses to other OARs in Eclipse™ and Elements® plans were lower than Precision® plans (Figure 2).