Pagets Disease

 History: 70-year-old male with history of prostate cancer, status post Prostatectomy. PSA level 0.25 ng/ml.  

Axial Fused 68GA-PSMA showing increased uptake in the left iliac bone. 

Axial CT image shows trabecular and cortical thickening with mottled appearance involving the left iliac bone. No underlying destructive lytic or sclerotic lesion.

Teaching points:

• PSA level < 10ng/ml nearly excludes bone metastases.
• PSMA uptake is secondary to overexpression of PSMA in the endothelial cells of neovasculature, probably stimulated by secreted angiogenic factors during bone remodeling in Paget's disease.

References:

1. Wolff JM, Bares R, Jung PK, Buell U, Jakse G. Prostate-specific antigen as a marker of bone metastasis in patients with prostate cancer. Urol Int. 1996;56(3):169-73. doi: 10.1159/000282834. PMID: 8860738.
2. Bourgeois S, Gykiere P, Goethals L, Everaert H, De Geeter FW. Aspecific Uptake of 68GA-PSMA in Paget Disease of the Bone. Clin Nucl Med. 2016 Nov;41(11):877-878. doi: 10.1097/RLU.0000000000001335. PMID: 27556795.
3. Artigas C, Alexiou J, Garcia C, Wimana Z, Otte FX, Gil T, Van Velthoven R, Flamen P. Paget bone disease demonstrated on (68)Ga-PSMA ligand PET/CT. Eur J Nucl Med Mol Imaging. 2016 Jan;43(1):195-196. doi: 10.1007/s00259-015-3236-x. Epub 2015 Oct 27. PMID: 26502983.
4. Shetty D, Patel D, Le K, Bui C, Mansberg R. Pitfalls in Gallium-68 PSMA PET/CT Interpretation-A Pictorial Review. Tomography. 2018 Dec;4(4):182-193. doi: 10.18383/j.tom.2018.00021. PMID: 30588504; PMCID: PMC6299744.