Local dose–effect relations for lung perfusion post stereotactic body radiotherapy

• Published in: Radiotherapy and oncology 2013-06, Vol.107 (3), p.398-402
• Main Authors: Scheenstra, Alize E.H, Rossi, Maddalena M.G, Belderbos, José S.A, Damen, Eugène M.F, Lebesque, Joos V, Sonke, Jan-Jakob
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Female; Hematology, Oncology and Palliative Medicine; Humans; Logistic Models; Lung - blood supply; Lung Neoplasms - diagnostic imaging; Lung Neoplasms - surgery; Lung perfusion reduction; Male; Middle Aged; NTCP; Radiosurgery; Radiotherapy Planning, Computer-Assisted; SBRT; SPECT; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2013.04.003

Abstract Purpose To model the local dose–effect relation for lung perfusion reduction in lung cancer patients treated with stereotactic body radiotherapy (SBRT). Materials and methods Forty-two patients having upper-lobe peripheral tumours 100 Gy and was best described by the logistic model with parameters (95% CI): M = 42.6% (40.7–44.6), D50 = 28.7 Gy (26.3–31.1) and k = 2.2 (1.8–2.5). A significant increase of this maximum effect to 65.2% was found at 15-months post-SBRT. Conclusions The relation between local dose and perfusion reduction in patients treated with SBRT can be modeled by a 3-parameter logistic model. This demonstrated relationship 4-months post-SBRT approaches a plateau for doses >100 Gy, where 90% of the maximum lung-perfusion reduction is observed at NTD = 78 Gy. A further perfusion reduction compared to 4-months post-SBRT was observed fifteen months post-SBRT.