ESTRO 2024 - Abstract Book

S3725

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

ESTRO 2024

Patient 1

Patient 2

Patient 3

Patient 4

Patient 5

Patient 6

Patient 7

Patient 8

Patient 9

Patient 10

Patient 11

Patient 12

Contralateral 3 & 4

3 & 4

4

N/A

3 & 4

3 & 4

N/A

4

3 & 4

3 & 4

3 & 4

3

Ipsilateral

4

4

Table 1: Lymph node levels which were omitted based on mimicking the patient population in the LyProX database. The ´N/A´ for patient 4 and 7 indicates, that LyProX estimates were similar to those of BaseP, thus the SelectP were identically to the BaseP.

Conclusion:

Opting for complete omission of contralateral regions in the CTVe for head and neck cancer proves to be the most effective strategy for achieving a notable reduction in mean doses to OAR and spill-over dose. Some reduction in spill-over dose can however still be achieved through selection of lymph node levels based on a conservative risk estimate. This study emphasizes the relevance of exploring methods to achieve benefits in reducing irradiation of OAR.

Keywords: Irradiation, elective target, head and neck

References:

[1] ‘Radiotherapy Guidelines 2020 DAHANCA Danish Head and Neck Cancer Group’. Accessed: Oct. 25, 2023. [Online]. Available: https://www.dmcg.dk/Kliniske-retningslinjer/kliniske-retningslinjer-opdelt-paa-dmcg/hoved hals-cancer/radiotherapy-guidelines-2020-dahanca-danish-head-and-neck-cancer-group/

[2] ‘LyProX · Lymphatic Progression eXplorer’. Accessed: Oct. 25, 2023. [Online]. Available: https://www.lyprox.org