Imaging Guidelines for Elevated PSA Levels
Introduction to Imaging Modalities
- The National Comprehensive Cancer Network recommends bone scan and CT/MRI of the abdomen and pelvis as the first-line imaging modalities for patients with elevated PSA levels, with selection based on clinical risk stratification 1
Bone Scan
- Bone scan is the standard for evaluation of bone metastases, particularly for patients with PSA ≥10 ng/mL, Gleason grade 4 or 5 present, bone pain, or locally advanced tumor (T3Nx or T1-4N1-3) 2
- Bone scan measures osteoblastic response to tumor rather than marrow metastases directly, with a minimum detection size of 0.4 cm 3
CT Scan of Abdomen/Pelvis
- CT scan of the abdomen and pelvis is indicated for patients with T3 or T4 disease, PSA >15 ng/mL, Gleason score ≥7, or nomogram-indicated probability of lymph node involvement >10% 1
- CT scans have limited sensitivity (lower detection limit of 0.5 cm) and specificity (abnormalities may represent fibrosis rather than tumor) 3
MRI
- Standard MRI techniques are recommended for high-risk patients, particularly for evaluating local extent of disease, assessing extracapsular extension, and planning for potential local therapy 1
- Advanced MRI techniques (endorectal MRI, MR perfusion/diffusion) may be useful when considering local salvage therapy for patients with rising PSA after radiation therapy 1
Special Considerations
- For patients with PSA failure after radical prostatectomy, bone scan and CT or MRI of abdomen/pelvis are recommended 1
- For patients with rising PSA after radiation therapy, bone scan and CT or MRI are recommended if the patient is a candidate for salvage therapy 1
- PET/CT with choline tracers may identify metastatic disease in men with biochemical recurrence after primary treatment failure, but requires further study 1
- Transrectal ultrasound (TRUS) and ProstaScint scans are not recommended for routine use due to limited evidence and controversy 3