How do you order a bone scan for an inpatient with Paget's disease?

How to Order a Bone Scan for Inpatient with Paget's Disease

For inpatients with Paget's disease requiring bone scan, order a whole-body radionuclide bone scan (Tc-99m bone scintigraphy) with SPECT/CT of areas of interest to determine the extent of metabolically active disease.

Indications for Bone Scan in Paget's Disease

Bone scans are a key diagnostic tool for Paget's disease of bone for the following reasons:

• Determines the full extent of metabolically active disease beyond what is visible on plain radiographs 1
• Helps differentiate between monostotic (single bone) and polyostotic (multiple bone) disease 2
• Establishes a baseline for monitoring disease progression or treatment response 2
• Identifies asymptomatic sites that may require monitoring or treatment 1

Specific Ordering Instructions for Inpatients

1. Test to order: Whole-body Tc-99m bone scan with SPECT/CT of areas of interest

   • Request "whole-body bone scan" rather than limited views to ensure all affected sites are identified 1
   • Include SPECT/CT for improved characterization of osseous pathology compared to planar imaging 3

2. Required clinical information on order:

   • Diagnosis: Paget's disease of bone (suspected or confirmed)
   • Symptomatic areas (if any): Specify location of pain or deformity
   • Relevant lab values: Include serum alkaline phosphatase levels
   • Treatment status: Note if patient has received bisphosphonate therapy
   • Reason for inpatient status: Important for prioritization

3. Patient preparation instructions:

   • Ensure adequate hydration before and after the procedure
   • Document any mobility limitations that may affect positioning
   • Note any recent fractures, surgeries, or other bone pathology

Bone Scan Protocol for Paget's Disease

The standard protocol should include:

• Three-phase bone scan for areas with active symptoms 3
• Whole-body delayed images to assess the full extent of disease 3
• SPECT/CT of areas with abnormal uptake for better anatomical correlation 3

Interpreting Results

Bone scan findings in Paget's disease typically show:

• Intense tracer uptake in affected bones
• Expansion of bone with increased activity throughout
• "Clover" pattern in vertebrae or "Mickey Mouse ears" appearance in skull
• Possible "cold" areas in very advanced disease (sclerotic phase)

Alternative Imaging Considerations

While bone scan is the recommended initial imaging for determining disease extent, consider:

• MRI: For suspected complications like nerve compression or malignant transformation 3
• CT: For detailed evaluation of bone architecture and fracture risk assessment 3
• PET/CT: Not routinely indicated but may be useful in cases where malignant transformation is suspected 3

Follow-up Recommendations

• Repeat bone scan is not routinely needed for monitoring unless:
  • New symptoms develop in previously unaffected areas
  • There is concern for malignant transformation
  • Treatment response assessment is needed when biochemical markers are normal 1

Common Pitfalls to Avoid

• Ordering CT first: CT has limited sensitivity for early Paget's disease and exposes patients to unnecessary radiation 3
• Limited views: Always order whole-body imaging as Paget's disease can be multifocal even when symptoms are localized 2
• Failure to correlate with labs: Always interpret bone scan findings in conjunction with alkaline phosphatase levels 2
• Overlooking SPECT/CT: Standard planar imaging may miss important details that SPECT/CT can reveal 3

By following these guidelines, you can ensure appropriate imaging for inpatients with Paget's disease to guide treatment decisions and monitor disease progression.