Table 2.
68Ga-PSMA-11 PET/CT findings in 115 men with BCR and very low PSA concentration.
| Variable | Value |
|---|---|
| Overall scan classification, % (n) | |
| Positive | 25.2% (29) |
| Negative | 74.8% (86) |
| Suspicious lesions on positive scans | |
| Total | 44 |
| Median (minimum–maximum) | 1 (1–4) |
| Number of lesions/positive scan, % (n) | |
| 1 | 69% (20/29) |
| 2 | 14% (4/29) |
| 3 | 14% (4/29) |
| 4 | 3% (1/29) |
| Type of lesions, % (n) | |
| Local recurrence | 25% (11/44) |
| Lymph node metastasis | 50% (22/44) |
| Bone metastasis | 25% (11/44) |
| Types of lesions on a positive scan, % (n) | |
| Local recurrence only | 24% (7/29) |
| Lymph node metastasis only | 34% (10/29) |
| Bone metastasis only | 24% (7/29) |
| Local recurrence + lymph node | |
| metastasis | 10% (3/29) |
| Local recurrence + bone metastasis | 3% (1/29) |
| Lymph node metastasis + bone | |
| metastasis | 3% (1/29) |
| SUVmax of suspicious lesions | |
| All suspicious lesions | |
| Median (minimum–maximum) | 5.3 (2.1–26.3) |
| Mean ± SD | 7.2 ± 5.3 |
| Local recurrence | |
| Median (minimum–maximum) | 5.7 (2.5–19.4) |
| Mean ± SD | 8.2 ± 5.6 |
| Lymph node metastasis | |
| Median (minimum–maximum) | 6.6 (2.1–26.3) |
| Mean ± SD | 8.3 ± 5.8 |
| Bone metastasis | |
| Median (minimum–maximum) | 3.3 (2.3–7.7) |
| Mean ± SD | 3.9 ± 1.5 |
Percentages represent proportions of the overall study sample or the subgroup with available data regarding a variable, as applicable. Due to rounding, not all percentages may add up to exactly 100%. Abbreviations: 68Ga, gallium-68; PSMA, prostate-specific membrane antigen; SD, standard deviation; and SUVmax, maximum standardized uptake value. a Lesion classifications are putative and not biopsy-confirmed. Figure 4 shows overall detection rates according to PSA doubling time categories (n = 83) (Panels A–B) and Gleason score categories (n = 107) (Panels C–D). Scan positivity is significantly higher (p = 0.04) among men with doubling times ≤ 12 months than among those with slower doubling times. Indeed, only 1/16 patients (6%) in the latter subgroup have positive 68Ga-PSMA-11 PET/CT. The overall suspicious lesion detection rate is also significantly higher (p = 0.01) in men with Gleason scores ≥ 7b than in patients with lower Gleason scores. Of note, there is no significant difference in the positivity rate between the study centers (p = 0.24).