Table 1.
Patients' demographics and PET/CT characteristics
| Parameters | Findings | With known primary cancer (n=229) | Without known primary cancer (n=96) | p-value |
| Age (years) | 59.5±14.2 | 54.3±16.5 | 0.250 | |
| Sex (male/female) | 146/67 | 88/34 | 0.380 | |
| Adrenal lesions | Metastasis | 163 (71.2%) | 0 (0.0%) | <0.001 |
| Benign | 66 (28.8%) | 96 (100.0%) | ||
| Primary cancer | Lung cancer | 103 (44.9%) | — | |
| Gastrointestinal cancer | 31 (13.5%) | — | ||
| Liver cancer | 25 (10.9%) | — | ||
| Others | 70 (30.7%) | — | ||
| PET/CT | ||||
| Left adrenal gland | Mass | 22 (9.6%) | 2 (2.0%) | 0.026 |
| Nodule | 78 (34.0%) | 44 (45.8%) | ||
| Hyperplasia | 62 (27.2%) | 32 (33.3%) | ||
| Normal | 67 (29.2%) | 18 (18.9%) | ||
| Right adrenal gland | Mass | 17 (7.45%) | 1 (1.0%) | 0.024 |
| Nodule | 43 (18.7%) | 17 (17.8%) | ||
| Hyperplasia | 27 (11.8%) | 15 (15.6%) | ||
| Normal | 142 (62.0%) | 63 (65.6%) | ||
| Unenhanced attenuation | >10 HU | 148 (64.6%) | 12 (8.4%) | <0.001 |
| ≤10 HU | 81 (36.4%) | 88 (91.6%) | ||
| SUVmax ratio | >2.5 | 52 (22.7%) | 3 (3.1%) | <0.001 |
| ≤2.5 | 109 (47.5%) | 25 (26.0%) | ||
| Absence of uptake | 68 (29.8%) | 68 (70.9%) | ||
| Unknown | — | 96% (100.0%) | ||
PET, positron emission tomography; SUVmax, maximum standardised uptake value.