Time and dose-related changes in lung perfusion after definitive radiotherapy for NSCLC

Publication date: Available online 1 December 2017
Source:Radiotherapy and Oncology
Author(s): Katherina P. Farr, Azza A. Khalil, Ditte S. Møller, Henrik Bluhme, Stine Kramer, Anni Morsing, Cai Grau
Background and purposeTo examine radiation-induced changes in regional lung perfusion per dose level in 58 non-small-cell lung cancer (NSCLC) patients treated with intensity-modulated radiotherapy (IMRT).Material and methodsNSCLC patients receiving chemo-radiotherapy (RT) of minimum 60 Gy were included prospectively in the study. Lung perfusion single-photon emission computed tomography (SPECT/CT) was performed before and serially after RT. Changes (relative to baseline, %) in regional lung perfusion were correlated with regional dose. Toxicity outcome was radiation pneumonitis (RP) CTC grades 2–5.ResultsPerfusion changes were associated with dose. Dose-dependent reduction in regional perfusion was observed at 3, 6 and 12 months of follow-up. Relative perfusion loss per dose bin was 4% at 1 month, 14% at 3 months, 13% at 6 months and 21% at 12 months after RT. In patients with RP, perfusion reduction was larger in high dose lung regions, compared to those without RP. Low dose regions, on the contrary, revealed perfusion gain in the patients with RP.ConclusionProgressive dose dependent perfusion loss is manifested on SPECT up to 12 months following IMRT. These findings suggest that the dynamic change in perfusion may have prognostic value in predicting radiation pneumonitis in NSCLC patients treated with IMRT.



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