What is your approach to bone imaging in MGUS?

Excellent question. For low-risk MGUS (M-spike <1.5 g/dL, normal serum free light chain ratio, and an IgG type protein), it is reasonable to forego any bone imaging in the absence of any relevant bone-related symptoms. The rate of bone involvement in patients with an M-spike of 1.5 g/dL was noted to be around 2.5% (Mangiacavalli et al., PMID 23859528), and the lifetime risk of progression is around 10%. For intermediate-risk MGUS and high-risk MGUS, reasonable to get a CT skeletal survey at baseline. If the predicted bone marrow plasmacytosis >=10% (i.e., Smoldering MM) is high (tools like the iStopMM calculator can be used for this https://istopmm.com/riskmodel/), then advanced imaging like WB-MRI is reasonable to pursue.