ESTRO 2024 - Abstract Book

S4253

Physics - Intra-fraction motion management and real-time adaptive radiotherapy

ESTRO 2024

σ

0.6

0.4

1.4

Intrafraction (iTMD)

Σ

0.6

0.3

0.6

σ

0.4

0.2

1.7

Delineation (D)

Σ

0.6

1.1

0.9

σ

0.2

0.4

5.0

Setup

Σ

0.5

0.5

0.5

σ

1.0

1.0

1.0

Penumbra (p)

2.9

2.9

2.9

PTV margins

PTV Non-ART

14.2

5.1

10.3

PTV ART

3.4

3.3

8.7

Table 1: Systematic (Σ) and random (σ) error values in mm for the tumour motion, delineation variability, and setup that are integrated in the total PTV margin.

Online-ART allows a reduction of 11.8, 1.8, and 1.6 mm in the antero-posterior, left-right, and supero-inferior axes, respectively. In the antero-posterior axis, the important PTV reduction between non-adaptive and online-ART PTV was largely due to the withdrawal of the interfraction TMT translation errors (Figure 1). Random delineation errors (σD) accounted for the most important part of the PTV margin along the supero-inferior axis in online-ART.