ESTRO 2024 - Abstract Book

S4761

Physics - Quality assurance and auditing

ESTRO 2024

1

0.9

2.5

2.8

0.89

-0.3

0.80

-0.5

2

1.0

1.6

1.6

0.85

0.1

0.76

0.2

3

1.2

6.6

5.5

0.83

-1.6

0.64

-2.6

4

1.3

2.7

2.1

0.87

-0.1

0.85

0.0

5

1.9

3.5

1.8

0.89

0.2

0.85

-0.4

6

3.3

5.5

1.7

0.90

0.8

0.87

-0.2

7

3.5

6.2

1.8

0.82

-1.9

0.85

0.1

8

5.3

12.8

2.4

0.89

-1.7

0.88

-0.4

9

6.3

13.1

2.1

0.89

0.5

0.86

-0.7

10

11.5

18.1

1.6

0.95

0.2

0.91

0.6

Avg

3.6

7.3

2.3

0.88

-0.4

0.83

-0.4

Table 1. ‘GTV (cc)’ : GTV volume for all ten patients measured on the mv-phase and ranked from small to large, ‘GTVacc_GT / GTV’ : Volume ratio between GTVacc_GT and GTV, and ‘GTVacc_Ar/Ve - GTVacc_GT (cc)’ : Volume difference between GTVacc_Ar/Ve and GTVacc_GT. Aria and Velocity both underestimated the accumulated GTV volumes with an average of 0.4cc. GTVacc_Ar was underestimated by more than 1cc for three patients (Pt. 3, 7, and 8) , and GTVacc_Ve was underestimated by more than 1cc for one patient (Pt. 3) with -2.6cc. No accumulated GTV volumes overestimated GTVacc_GT by more than 1cc. DC_Ar>DC_Ve for all patients except one (Pt. 7) .

Figure 2 shows that Aria generally outperforms Velocity, especially for tumor volumes below 1.3cc. This is primarily due to the larger overlap volumes between GTVacc_Ar and GTVacc_GT. For Pt. 3 , with a tumor volume of 1.2cc combined with the largest tumor motion, DC_Ve=0.64 while DC_Ar=0.83.

Conclusion: