ESTRO 2024 - Abstract Book

S5875

RTT - Service evaluation, quality assurance and risk management

ESTRO 2024

Time in treatment room (hours)

PTV Volume (cc)

Acute

post

Beam on time (minutes)

Pathway length (days)

PS

at

Arc geometry

Patient Age

Sex

treatment toxicity

MU's

referral

2 full arcs (arms down)

3

64

142.4

M

nil

3

1:15

6.5

9127

56

4

75

106.0

M

Fatigue G1

2

2:15

6.8

3 half arcs 9517

93

Fatigue G2

5

70

98.3

M

2

2:20

11.3

3 half arcs 15868

53

Chest pain G1

6

59

47.8

F

Nil

2

3:00

11.8

3 full arcs 16491

112

7

88

56.6

M

Fatigue G1

2

1:50

11.6

3 full arcs 16243

67

8

56

134.5

M

*

2

*

6.8

3 full arcs 9458

41

Averages 69

91.5

2:05

8.4

11744

64

* This patient was too ill to treat.

Conclusion:

Our local protocols are continuously reviewed as we become more experienced in delivering cSABR.

Planning challenges include combining multi-modality data for precise target delineation and minimising dose to critical organs. Arc geometry varied depending on target volume size and location, but was generally three half arcs for a lateral volume and three full arcs for volumes extending medially. We have seen an increased pathway length compared to our standard 2 week cancer pathway, due to the need for MDT input at all stages of the process. Beam on time is over 3 times longer than a standard SABR treatment. The patient spends longer in the treatment room necessitating a 2 hour treatment slot, with flexibility to allow for individual setup needs.

The image quality of the CBCT was sufficient to give confidence in the patient set up. The presence of metal caused artefacts which did not obscure the volume for image matching, and in some cases has been useful as a surrogate.

In the future we aim to widen our experience and knowledge through national and international collaboration and involvement in clinical trials.

Keywords: Cardiac SABR, VT,