PuSH - Publikationsserver des Helmholtz Zentrums München

Winter, J. ; Ellerbrock, M.* ; Jäkel, O.* ; Greilich, S.* ; Bangert, M.*

Analytical modeling of depth-dose degradation in heterogeneous lung tissue for intensity-modulated proton therapy planning.

Phys. Imag. Radiat. Oncology 14, 32-38 (2020)
Verlagsversion Forschungsdaten DOI
Open Access Gold
Creative Commons Lizenzvertrag
Background and purpose: Proton therapy may be promising for treating non-small-cell lung cancer due to lower doses to the lung and heart, as compared to photon therapy. A reported challenge is degradation, i.e., a smoothing of the depth-dose distribution due to heterogeneous lung tissue. For pencil beams, this causes a distal falloff widening and a peak-to-plateau ratio decrease, not considered in clinical treatment planning systems. Materials and methods: We present a degradation model implemented into an analytical dose calculation, fully integrated into a treatment planning workflow. Degradation effects were investigated on target dose, distal dose falloffs, and mean lung dose for ten patient cases with varying anatomical characteristics. Results: For patients with pronounced range straggling (in our study large tumors, or lesions close to the mediastinum), degradation effects were restricted to a maximum decrease in target coverage (D95 of the planning target volume) of 1.4%. The median broadening of the distal 80–20% dose falloffs was 0.5 mm at the maximum. For small target volumes deep inside lung tissue, however, the target underdose increased considerably by up to 26%. The mean lung dose was not negatively affected by degradation in any of the investigated cases. Conclusion: For most cases, dose degradation due to heterogeneous lung tissue did not yield critical organ at risk overdosing or overall target underdosing. However, for small and deep-seated tumors which can only be reached by penetrating lung tissue, we have seen substantial local underdose, which deserves further investigation, also considering other prevalent sources of uncertainty.
Altmetric
Weitere Metriken?
Zusatzinfos bearbeiten [➜Einloggen]
Publikationstyp Artikel: Journalartikel
Dokumenttyp Wissenschaftlicher Artikel
Schlagwörter Bragg Peak Degradation ; Depth-dose Degradation ; Heterogeneous Lung Tissue ; Non-small-cell Lung Carcinoma ; Proton Therapy ; Radiotherapy Planning
ISSN (print) / ISBN 2405-6316
e-ISSN 2405-6316
Quellenangaben Band: 14, Heft: , Seiten: 32-38 Artikelnummer: , Supplement: ,
Verlag Elsevier
Begutachtungsstatus Peer reviewed