Table 3.
Summary of PSMA-RADS Version 1.0 for the interpretation of PSMA-PET imaging.
| PSMA-RADS 1.0 | ||
|---|---|---|
| Category | Findings | Action |
| PSMA-RADS-1 (benign) | ||
| PSMA-RADS-1A | Benign lesion characterized by biopsy or pathognomonic finding on anatomic imaging and without abnormal uptake | |
| PSMA-RADS-1B | Benign lesion characterized by biopsy or pathognomonic finding on anatomic imaging and with focal radiotracer uptake | |
| PSMA-RADS-2 (likely benign) |
Equivocal uptake (focal, but low level such as blood pool) in soft-tissue or in a bone site atypical of PCa involvement | |
| PSMA-RADS-3 (equivocal) | Consider further work-up | |
| PSMA-RADS-3A | Equivocal uptake in soft-tissue site typical of PCa involvement. | Lesion targetable: biopsy is suggested. Alternatively, follow-up imaging (either anatomic or PSMA-targeted PET/CT) after 3–6 months is recommended. |
| PSMA-RADS-3B | Equivocal uptake in bone lesion not definitive but also not atypical of PCa on anatomic imaging. | Comparison to other imaging modalities (bone scan, [18F]NaF PET, or tumor-protocol MRI images) or bone biopsy. Alternatively, follow-up imaging (either anatomic or PSMA-targeted PET/CT) after 3–6 months is recommended. |
| PSMA-RADS-3C | Lesions that would be atypical for PCa but have high levels of uptake. The likelihood of non-prostatic malignancy or another benign tumor is high. | Biopsy to histologically confirm the diagnosis is often preferred. Alternatively, organ-specific follow-up imaging may be done (e.g., liver-protocol MRI to evaluate possible primary hepatocellular carcinoma). |
| PSMA-RADS-3D | Lesion suggestive of malignancy on anatomic imaging but lacking uptake. | Consider non-prostatic malignancy, neuroendocrine PCa, and an uncommon case of prostate adenocarcinoma that fails to express PSMA. Biopsy to histologically confirm the diagnosis is often preferred; alternatively, organ-specific follow-up imaging may be done. |
| PSMA-RADS-4 (Pca highly likely) |
Intense uptake in sites typical of PCa but lacking definitive findings on conventional imaging. | No biopsy confirmation will be needed, although tissue for genomic analysis (or other purposes) may be useful. |
| PSMA-RADS-5 (Pca almost certainly present) |
Intense uptake in sites typical of PCand having corresponding findings on conventional imaging. | No biopsy confirmation will be needed, although tissue for genomic analysis (or other purposes) may be useful. |
Adapted from Rowe SP et al. [9]. Abbreviations: PSMA, Prostate-specific membrane antigen; RADS, Reporting and Data Systems; PCa, prostate cancer; NaF, sodium fluoride; MRI, magnetic resonance imaging; PET/CT, positron emission tomography/computed tomography.