Characteristic | Center 1, Freiburg | Center 2, Nanjing | Center 3, Hannover |
Median age (y) | 70 (range, 48–88) | 69 (range, 55–84) | 71.5 (range, 59–84) |
Median PSA (ng/mL) | 13.1 (range, 4.4–218) | 13.3 (range, 4.04–110) | 12.8 (range, 1.91–108.10) |
Gleason score (n) | |||
6 | 5 (3.4%) | 4 (8.9%) | 0 |
7a | 44 (30.1%) | 12 (26.7%) | 3 (15%) |
7b | 43 (29.9%) | 12 (26.7%) | 3 (15%) |
8 | 24 (16.7%) | 10 (22.2%) | 6 (30%) |
9 | 19 (13.2%) | 7 (15.5%) | 8 (40%) |
Unknown | 9 (6.3%) | 0 | 0 |
cT stage (n) | |||
2 | 89 (61.8%) | 14 (30.8%) | 6 (30%) |
3 | 55 (38.2%) | 31 (69.2%) | 14 (70%) |
Total patients with 68Ga-PSMA PET/CT (n) | 125 | 45 | 20 |
Patients in training cohort (n) | 97 | 45 | |
Patients in validation cohort (n) | 10 | ||
Patients in testing cohort (n) | 18 | 20 | |
Patients with histology reference (n) | 18 | ||
Patients with 18F-PSMA-PET/CT, total (n) | 19 | ||
Patients in testing cohort (n) | 19 | ||
Patients with histology reference (n) | 11 |
The CNN was trained on 142 patients with 68Ga-PSMA-11 PET/CT from centers 1 and 2. From center 1, 10 patients with 68Ga-PSMA-11 PET/CT were pseudorandomly selected for validation. Finally, internal testing was performed on 18 and 19 patients with 68Ga-PSMA-11 PET/CT (cohort 1) or 18F-PSMA-1007 (cohort 2) PET/CT, respectively. All patients with histologic samples were in the testing cohorts. External validation was performed on 20 patients with 68Ga-PSMA-11 PET/CT (cohort 3) from center 3. Datasets from center 2 (n = 42) were used only for training and from center 3 (n = 20) only for testing. Differences in clinical parameters of the 2 test cohorts with 68Ga-PSMA-11 PET/CT were analyzed. No differences in PSA and cT stage were observed (P > 0.05). Patients from center 3 had statistically significant (P = 0.035) higher Gleason scores.