BACKGROUND: Radiation-induced lung injury (RILI) is an important dose-limiting
toxicity during thoracic radiotherapy. The purpose of this study is to
investigate single photon emission computed tomography (SPECT) perfusion-weighted
functional dose-volume histogram (FDVH) for predicting RILI in non-small cell
lung cancer (NSCLC) patients treated with definitive chemoradiotherapy.
METHODS: Fifty-seven locally advanced NSCLC patients receiving chemoradiotherapy
were enrolled prospectively. Patients had treatment scans and dose calculations
to provide a standard dose-volume histogram (DVH). Fusion of SPECT and computed
tomography scans provided perfusion-weighted FDVH and associated functional
dosimetric parameters (relative volumes of functional lung receiving more than a
threshold dose of 5 - 60 Gy at increments of 5 Gy [FV5 - FV60]). The predictive
abilities of FDVH and DVH were calculated and compared based on the area under
receiver operating characteristic (ROC) curve (AUC).