Acute radiation oesophagitis associated with 2-deoxy-2-[18F]fluoro-d-glucose uptake on positron emission tomography/CT during chemo-radiation therapy in patients with non-small-cell lung cancer.

INTRODUCTION: Acute radiation oesophagitis (ARO) is frequently experienced by patients receiving concurrent chemo-radiation therapy (cCRT) for non-small-cell lung cancer (NSCLC). We investigated ARO symptoms (CTCAE v3.0), radiation dose and oesophageal FDG PET/CT uptake.

METHOD: Candidates received cCRT (60 Gy, 2 Gy/fx) and sequential FDG PET/CT (baseline FDG0 , FDGwk2 and FDGwk4 ). Mean and maximum standardized uptake value (SUVmean and SUVmax) and radiation dose (Omean and Omax ) were calculated within the whole oesophagus and seven sub-regions (5-60 Gy).

RESULTS: Forty-four patients underwent FDG0 and FDGwk2 , and 41 (93%) received FDGwk4 , resulting in 129 PET/CT scans for analysis. Of 29 (66%) patients with ≥ grade 2 ARO, SUVmax (mean ± SD) increased from FDG0 to FDGwk4 (3.06 ± 0.69 to 3.83 ± 1.27, P = 0.0019) and FDGwk2 to FDGwk4 (3.10 ± 0.75 to 3.83 ± 1.27, P = 0.0046). Radiation dose (mean ± SD) was higher in grade ≥2 patients; Omean (47.5 ± 20 vs 53.9 ± 10.2, P = 0.0061), Omax (13.7 ± 9.6 vs 20.1 ± 10.6, P = 0.0009) and V40 Gy (8.0 ± 8.2 vs 11.9 ± 7.3, P = 0.0185).

CONCLUSIONS: FDGwk4 SUVmax and radiation dose were associated with ≥ grade 2 ARO. Compared to subjective assessments, future interim FDG PET/CT acquired for disease response assessment may also be utilized to objectively characterize ARO severity and image-guided oesophageal dose constraints.