Table 1.
Patient characteristics
| Clinical variables | 4 week treatment interval | 6 week treatment interval | P-value |
|---|---|---|---|
| Age at first cycle of PSMA RLT (years), median (range) | 67 (52–83) | 70 (58–87) | 0.15 |
| Time period between initial diagnosis and 1st RLT (years), median (range)# | 4 (1–16) | 4.5 (2–25) | 0.2 |
| No. of treatment cycles up to the second Interim PSMA-ligand PET imaging | 97 | 66 | 0.0002 |
| Cumulative activity per patient up to the second Interim PSMA-ligand PET imaging (GBq), median (range) | 23.6 (21.3–46.2) | 15.8 (13.6–33.4) | < 0.0001 |
| Activity per cycle up to the second Interim PSMA-ligand PET imaging (GBq), median (range) | 7.4 (6.9–7.8) | 7.5 (3.4–8.4) | 0.06 |
| Gleason score, median (range)# | 9 (5–9) | 9 (6–10) | 0.36 |
| Baseline laboratory values, median (range) | |||
| LDH (U/l)# | 263 (171–1355) | 264 (188–773) | 0.99 |
| Hb (g/dl) | 11.5 (8.0-14.9) | 11.5 (7.5–14.5) | 0.6 |
| Leukocytes (tsd/µl) | 6.3 (2.6–13.7) | 6.9 (3.5–9.4) | 0.87 |
| Platelets (tsd/µl) | 224 (124–512) | 239 (99–491) | 0.58 |
| Creatinine (mg/dl) | 0.9 (0.6–1.2) | 0.8 (0.7–2.3) | 0.82 |
| AST (U/l) | 27 (18–115) | 28 (14–66) | 0.84 |
| ALT (U/l) | 16 (7–50) | 18 (7–57) | 0.81 |
| AP (U/l) | 139 (73–759) | 117 (41–650) | 0.35 |
| PSA (ng/ml) | 144.0 (3.7–2760.0) | 60.8 (6.2–857) | 0.006 |
| Previous systemic treatments, n (%) | |||
| Abiraterone | 18 (78.3) | 20 (87.0) | 0.7 |
| Enzalutamide | 16 (69.6) | 14 (60.9) | 0.76 |
| Previous second generation antihormonal treatment (Abiraterone and/or Enzalutamide)# | 22 (95.7) | 22 (95.7) | 1.0 |
| Docetaxel# | 17 (73.9) | 17 (73.9) | 1.0 |
| Cabazitaxel# | 4 (17.4) | 4 (17.4) | 1.0 |
| Previous chemotherapy | 17 (73.9) | 17 (73.9) | 1.0 |
| 223Radium | 1 (4.3) | 1 (4.3) | 1.0 |
| Site of metastasis, n (%) | |||
| Lymph node (M1a)# | 15 (65.2) | 15 (65.2) | 1.0 |
| Bone (M1b)# | 23 (100) | 23 (100) | 1.0 |
| Visceral, overall (M1c) # | 5 (21.7) | 5 (21.7) | 1.0 |
| Liver | 2 (8.7) | 0 | |
| Lung | 1 (4.4) | 3 (13.0) | |
| Adrenal | 1 (4.4) | 2 (8.7) | |
| Others | 2 (8.7) | 0 | |
AP alkaline phosphatase, Hb haemoglobin, LDH lactate dehydrogenase, PSMA RLT prostate-specific membrane antigen targeted radioligand therapy, PSA prostate-specific antigen
# = matching criteria