ESTRO 2024 - Abstract Book

S1679

Clinical - Lung

ESTRO 2024

plans, but angle optimization reduced the total number of monitor units (MUs) (angle-optimized plans: 573.34±221.34, manually planned: 621.67±219.71, p < 0.05). In the reduced lung dose strategy plans, angle optimization achieved similar results to manual planning while reducing the total number of MUs (angle-optimized plans: 729.82±353.33, manually planned: 729.82±353.33, p < 0.05). In the reduced heart dose strategy plans, LUNG PTV's V20 and Dmean were higher in angle-optimized plans (28.62±9.46%, 908.32±348.95 cGy) compared to manually planned ones (25.45±11.47%, 862.95±396.79 cGy, p < 0.05). For the reduced spinal cord dose strategy plans, apart from the conformity index (CI) (angle-optimized plans: 0.663±0.114, manually planned: 0.688±0.097, p < 0.05), there were no differences in other clinical parameters.

Conclusion:

Angle optimization demonstrates certain advantages in relatively complex lung cancer radiotherapy treatment planning.

Keywords: Angle optimization ， pruning-local optimization ， lung

1588

Digital Poster

Lung SBRT in patients with prior thoracic surgery and/or radiotherapy and impaired lung function

Anna Stenger-Weisser, Philippe Logaritsch, Gabriela Studer

Cantonal Hospital Lucerne, Radiation Oncology, Lucerne, Switzerland

Purpose/Objective:

SBRT has become a valuable therapeutic option for patients with primary lung tumors. The role of lung SBRT in patients with impaired lung function who have been treated for primary lung cancer with prior surgery and/or radiotherapy is unclear.

Material/Methods:

We conducted a retrospective analysis of our database for lung SBRT, focusing on consecutive patients treated for a lung lesion with curative intent between 01/2018 and 06/2023. Among 123 patients, we specifically evaluated those with a history of prior lung surgery and/or radiotherapy, in conjunction with a coexisting lung disease such as COPD, pulmonary fibrosis, or others. The standard SBRT fractionation included 3x 15 Gy, 4x 12 Gy, or 8x 7.5 Gy, based on lesion location. Follow-up primarily included clinical evaluations and CT scans.

Results: