Table 2 Summary of tumour hypoxic volume results using 4-h hypoxia PET-CT. Three thresholds were used to define progressively higher hypoxia PET tracer uptake: TBR ≥ 1.4 (a), TBR ≥ 1.6 (b), and TBR ≥ 1.8 (c)

(a)

 Baseline scan

15.2 (3.1–39.7)

29.8 (5.7–44.6)

18.1 (5.9–43.8)

0.0 (0.0–2.9)

2.2 (0.0–28.5)

6.0 (2.2–26.6)

7.3 (2.1–23.9)

0.0 (0.0–8.1)

 Pre-surgery scan

9.2 (0.0–32.1)

17.9 (1.5–23.4)

10.1 (1.9–27.2)

1.44 (0.0–3.4)

2.1 (0.0–32.1)

6.8 (2.3–23.4)

9.6 (2.3–27.2)

0.5 (0.0–11.4)

 Change from baseline

− 10.4% (− 54.2 to − 1.05)

− 33.3% (− 61.7 to 0.6)

− 23.5% (− 49.4 to 0.5)

0.0% (− 33.7 to 4.6)

0.0% (− 5.6 to 9.6)

 + 0.2% (− 9.1 to 22.2)

 + 20.9% (− 0.4 to 29.8)

0.0% (− 13.7 to 7.0)

(b)

 Baseline scan

9.3 (0.0–16.8)

10.2 (2.4–34.8)

20.8 (8.9–57.4)

0.0 (0.0–1.9)

2.4 (0.0–15.8)

2.5 (0.2–19.2)

6.1 (9.5–18.3)

0.0 (0.0–5.4)

 Pre-surgery scan

3.8 (0.0–17.6)

4.7 (0.3–29.7)

3.8 (0.6–32.1)

0.0 (0.0–2.4)

0.5 (0.0–13.0)

3.1 (0.6–15.4)

6.9 (1.0–19.1)

0.0 (0.0–5.2)

 Change from baseline

− 11.3% (− 45.5 to 2.0)

− 49.3% (− 66.9 to − 4.4)

− 50.5% (− 61.6 to 2.1)

0.0% (− 28.9 to 29.6)

0.0% (− 11.3 to 8.5)

0.0% (− 18.2 to 28.8)

 + 5.1% (− 10.3 to 34.8)

0.0% (− 8.5 to 8.0)

(c)

 Baseline scan

3.5 (0.0–11.7)

2.0 (0.5–22.8)

4.0 (0.4–22.9)

0.0 (0.0–0.7)

0.0 (0.0–7.9)

1.4 (0.0–7.9)

0.5 (0.0–10.9)

0.0 (0.0–3.7)

 Pre-surgery scan

0.7 (0.0–11.2)

0.4 (0.0–14.6)

0.9 (0.0–13.3)

0.0 (0.0–0.0)

0.0 (0.0–6.5)

1.3 (0.1–7.6)

3.4 (0.3–10.3)

0.0 (0.0–6.5)

 Change from baseline

− 14.8% (− 46.9 to 5.42)

− 23.7% (− 65.9 to 6.6)

− 81.0% (− 84.6 to − 5.6)

0.0% (− 41.6 to 24.3)

0.0% (− 19.6 to 8.7)

0.0% (− 23.8 to 10.5)

 + 6.0% (− 18.8 to 12.8)

0.0% (− 7.2 to 7.4)