Table 3.
Prognostic value of metabolic parameters on PET and histopathological tumour response for survival
| n (%) | Univariate Cox regression test | Univariate Cox regression test | |||||
|---|---|---|---|---|---|---|---|
| OS HR | 95% CI | p | DFS HR | 95% CI | p | ||
| Baseline SUVmax | |||||||
| SUV1max ≥9.70 | 20 (57.1) | 1.000 | 0.044 | 1.000 | 0.030 | ||
| SUV1max < 9.70 | 15 (42.9) | 2.589 | 1.025–6.535 | 2.797 | 1.107–7.071 | ||
| Post-treatment SUVmax | |||||||
| SUV2max ≥3.75 | 13 (44.8) | 1.000 | 0.376 | 1.000 | 0.352 | ||
| SUV2max < 3.75 | 16 (55.2) | 1.627 | 0.554–4.780 | 1.658 | 0.572–4.812 | ||
| Metabolic response based on ∆SUVmax | |||||||
| ∆SUVmax ≥ 5.75 | 17 (58.6) | 1.000 | 0.112 | 1.000 | 0.066 | ||
| ∆SUVmax < 5.75 | 12 (41.2) | 2.223 | 0.829–6.013 | 2.563 | 0.941–6.981 | ||
| Metabolic response based on ROC analysis of ∆%SUVmax | |||||||
| ∆%SUVmax ≥70% | 12 (41.2) | 1.000 | 0.063 | 1.000 | 0.028 | ||
| ∆%SUVmax <70% | 17 (58.6) | 2.956 | 0.945–9.247 | 3.614 | 1.150–11.533 | ||
| Baseline MTV (cm3) | |||||||
| MTV1 ≥47.30 | 18 (51.4) | 1.000 | 0.141 | 1.000 | 0.133 | ||
| MTV1 < 47.30 | 17 (48.6) | 1.996 | 0.795–5.013 | 2.031 | 0.806–5.118 | ||
| Post-treatment MTV (cm3) | |||||||
| MTV2 ≥12.00 | 10 (34.5) | 1.000 | 0.817 | 1.000 | 0.795 | ||
| MTV2 < 12.00 | 16 (55.2) | 0.860 | 0.241–3.074 | 0.845 | 0.238–3.003 | ||
| Missing | 3 (10.3) | ||||||
| Metabolic response based on ∆MTV | |||||||
| ∆MTV ≥39.40 | 16 (55.2) | 1.000 | 0.305 | 1.000 | 0. 362 | ||
| ∆MTV < 39.40 | 10 (34.5) | 1.182 | 0.583–5.639 | 1.698 | 0.544–5.296 | ||
| Missing | 3 (10.3) | ||||||
| Metabolic response based on ∆% MTV | |||||||
| ∆%MTV ≥80% | 10 (34.5) | 1.000 | 0.707 | 1.000 | 0. 681 | ||
| ∆%MTV < 80% | 16 (55.2) | 0.792 | 0.235–2.672 | 0.775 | 0.231–2.605 | ||
| Missing | 3 (10.3) | ||||||
| Metabolic response based on various cut-offs of ∆%SUVmax | |||||||
| ∆%SUVmax = 100% | 4 (13.8) | 1.000 | 1.000 | ||||
| ∆%SUVmax ≥70–99% | 8 (27.6) | 0.402 | 0.056–2.898 | 0.366 | 0.454 | 0.063–3.247 | 0.431 |
| ∆%SUVmax ≥35–69% | 14 (48.3) | 1.552 | 0.331–7.727 | 0.577 | 2.137 | 0.460–9.922 | 0.332 |
| ∆%SUVmax <35% | 3 (10.3) | 3.241 | 0.429–24.495 | 0.254 | 3.718 | 0.491–28.183 | 0.204 |
| Histopathological tumour response | |||||||
| TRG1a–1b | 16 (45.7) | 1.000 | 1.000 | ||||
| TRG2–3 | 19 (54.3) | 8.461 | 2.355–30.396 | 0.001 | 6.385 | 2.019–20.195 | 0.002 |
Statistical significant result is in bold
Post-treatment scans in five patients were excluded from analysis due to oesophageal stent insertion. One patient was excluded due to significant difference in uptake times between the two scans
PET positron emission tomography, OS overall survival, DFS Disease-free survival, HR Hazard ratio, CI confidence interval, n number of patients, SUV1 max baseline SUVmax, SUV2 max post-treatment SUVmax, ∆SUV max absolute reduction in SUVmax, ∆%SUV max relative reduction in SUVmax, MTV metabolic tumour volume, MTV1 Baseline MTV, MTV2 post-treatment MTV, ∆MTV absolute reduction in MTV, ∆%MTV relative reduction in MTV, TRG tumour regression grade