Table 4.
Positive predictive value (PPV) estimates for surveillance for ultrasonography (US), computed tomography (CT), positron emission tomography (PET), and PET-CT, stratified by level of risk and metastatic site*
| Site and risk level | 5-y recurrence probability, % | PPV, % (95% CI) |
|||
| US | CT | PET | PET-CT | ||
| Lymph node metastasis | |||||
| Low risk | 5 | 83 (36 to 100) | 52 (12 to 88) | 70 (22 to 96) | 77 (19 to 99) |
| Intermediate risk | 15 | 94 (68 to 100) | 78 (43 to 95) | 88 (60 to 98) | 92 (59 to 100) |
| High risk | 30 | 98 (83 to 100) | 90 (68 to 99) | 95 (81 to 100) | 97 (76 to 100) |
| Distant metastasis | |||||
| Low risk | 5 | — | 13 (27 to 32) | 20 (6 to 44) | 33 (9 to 61) |
| Intermediate risk | 15 | — | 34 (16 to 52) | 46 (27 to 67) | 63 (38 to 82) |
| High risk | 30 | — | 55 (38 to 73) | 67 (50 to 82) | 80 (64 to 93) |
*
The 95% confidence intervals (CIs) were calculated by assuming the total number of patients in the study was 100.