Table 2.
Summary of the main results of the included studies.
| References | PET/CT parameters | Timing and indication of PET/CT | End point | Univariate analysisa | Multivariate analysisa |
|---|---|---|---|---|---|
| Before thyroidectomy | |||||
| Kwon et al. (14) | Tumor-to-liver uptake ratio (TLR) | Within 3 months of surgery | DFS | NR | NS |
| Lee et al. (15) | SUVmax of metastatic lymph nodes | Before surgery | RFS | p = 0.025 | NR |
| Kim et al. (16) | FDG uptake of primary tumor | Before surgery | RFS | NS | NR |
| FDG uptake of lateral neck node metastasis | RFS | NS | NR | ||
| Kim et al. (17) | FDG uptake of primary tumor | Within 3 months prior to surgery | DFS | p = 0.0049 | NS |
| Qiu et al. (18) | FDG uptake of bone lesions | Before thyroidectomy or after 131-I therapy | OS | p = 0.013 | HR = 4.13 (95% CI = 3.96–4.27), p = 0.009 |
| After thyroidectomy | |||||
| Pryma et al. (19) | SUVmax | After thyroidectomy. An elevated Tg, abnormal imaging, high-risk histopathology | OS | p < 0.01 | NR |
| Nagamachi et al. (20) | FDG uptake | Before 131-I therapy | OS | p < 0.05 | RR = 5.01 (95% CI = 3.41–6.62), p < 0.011 |
| Pace et al. (21) | FDG uptake | Before 131-I therapy | DFS | p = 0.001 | χ2 = 16.1, HR = 5.5, p < 0.0005 |
| Salvatore et al. (22) | FDG uptake | Before or after 131-I therapy | PFS | p = 0.000 | NR |
| Zhu et al. (23) | FDG uptake | Before remnant ablation. In setting of suspicion or proven metastases | OS | p < 0.05 | NR |
| Gaertner et al. (24) | FDG uptake, SUVmax, volume of lesions | After 131-I therapy. A negative DxWBS with elevated Tg, high risk, known distant metastases | OS | p = 0.001 | p < 0.05 |
| Wang et al. (25) | FDG uptake | After remnant ablation, an elevated Tg | DFS | p < 0.001 | χ2 = 26.3, p < 0.0001 |
| OS | p < 0.05 | NS | |||
| Robbins et al. (26) | FDG uptake, number of lesions, SUVmax | An elevated Tg with negative WBS, surveillance in Hürthle cell carcinoma | OS | p < 0.001 | RR = 7.69 (95% CI = 2.17–24.4), p < 0.05 |
| Deandreis et al. (27) | FDG uptake, SUVmax, the number of lesions | At the time of diagnosis or during follow-up. To detect or assess metastases | PFS | p = 0.01 | NS |
| OS | p = 0.009 | p = 0.001 | |||
| Hong et al. (28) | FDG uptake, SUVmax | The interval between PET/CT and RxWBS was <12 months. | DSS | p < 0.001 | HR = 10.53 (95% CI = 1.95–56.75), p = 0.006 |
| Akkas et al. (29) | Location of lesions, number of lesions, SUVmax | After I-131 treatment in recurrent DTC. An elevated Tg with a negative RxWBS or a positive RxWBS with an elevated Tg | DSS | NS | NR |
| Masson-Deshayes et al. (30) | SUVmax, SULpeak, MTV, TLG, number of lesions | After the diagnosis of distant metastases | PFS | HR = 3.96 (95% CI = 1.76–8.89), p = 0.001 | p < 0.05 |
| OS | HR = 4.41 (95% CI = 1.39–14.01), p = 0.012 | NR | |||
| Marcus et al. (31) | FDG uptake | After I-131 treatment. An elevated Tg and a negative WBS or at the time of suspected recurrence | OS | HR = 6.1 (95% CI = 3.0–14.3), p < 0.0001 | p < 0.0001 |
| Manohar et al. (32) | MTV, TLG | After 131-I therapy. An elevated Tg with a negative WBS | DFS | HR = 1.21 (95% CI = 1.05–1.39), p = 0.005 | NR |
| OS | HR = 1.17 (95% CI = 0.99–1.39), p = 0.05 | NR | |||
| Pitoia et al. (33) | FDG uptake | After remnant ablation | OS | p = 0.0003 | HR = 9.11 (95% CI = 0.99–32.22), p = 0.0003 |
| Sabra et al. (34) | FDG uptake | NR | PFS | p < 0.0001 | NR |
| Kang et al. (35) | SUVmax | Within 6 months before surgery for recurrent PTC. As preoperative workup | DFS | p < 0.001 | NR |
| Wang et al. (36) | ΔSUVmax%, ΔMTV%, ΔTLG% | In the setting of the apatinib treatment | PFS | p = 0.0001 | NR |
| Kim et al. (37) | FDG uptake | In the setting of the sorafenib treatment | PFS | NS | NR |
| Marotta et al. (38) | Baseline SUVmax, reductions in SUVmax | In the setting of the sorafenib treatment | PFS | NS | NR |
NR, not reported; NS, not significant; HR, hazard ratio; RR, relative risk; 95% CI, 95% confidence interval.
a
Univariate analysis was performed using Kaplan–Meier survival plots and the log-rank test or the Cox regression model. Multivariate analysis was performed using the Cox regression model or Cox proportional hazards model. All effect values are the highest values in the studies.