When should a patient with a history of cancer, such as breast, prostate, or lung cancer, or symptoms like unexplained bone pain or osteoporosis, undergo a bone scan?

When to Check Bone Scan in Cancer Patients

Bone scan indications are cancer-specific: obtain bone scintigraphy for locally advanced breast cancer regardless of symptoms, high-risk prostate cancer (PSA ≥20 ng/mL with T1 disease, PSA ≥10 ng/mL with T2 disease, Gleason ≥8, or T3/T4 disease), and lung or renal cancer only when bone metastases are clinically or biochemically suspected. 1, 2

Breast Cancer

For locally advanced breast cancer, bone imaging is mandatory as part of full staging workup, preferably with CT or PET/CT rather than bone scintigraphy alone. 1

• Patients with chest wall or regional nodal recurrence require full re-staging including bone imaging due to high risk of concomitant distant metastases 1
• Any patient with persistent localized bone pain warrants immediate bone imaging regardless of disease stage 1, 3
• Large tumors (≥5 cm), positive axillary nodes, or aggressive tumor biology are high-risk features requiring bone imaging 1
• PET/CT can replace the combination of bone scan plus CT when available, and is preferred by the American College of Radiology as the single most comprehensive test 3

Common pitfall: Do not rely on chest radiography or plain rib films for suspected metastases—they have very low sensitivity and will miss early disease 3

Prostate Cancer

Bone scintigraphy is indicated at diagnosis for intermediate-to-high risk disease only, not for all prostate cancer patients. 1, 2

Specific thresholds for initial staging: 2

• PSA ≥20 ng/mL with T1 disease
• PSA ≥10 ng/mL with T2 disease
• Gleason score ≥8 (any stage)
• T3 or T4 disease (any PSA)

Post-treatment surveillance indications: 2

• PSA fails to reach undetectable levels after radical prostatectomy
• Previously undetectable PSA becomes detectable and rises on 2 consecutive measurements
• Rising PSA after radiation therapy with positive digital rectal exam in candidates for additional local therapy
• Bone pain or other symptoms suggesting disease progression 1

Routine bone imaging is NOT recommended without biochemical relapse or symptoms. 1

Lung Cancer (NSCLC)

Bone scintigraphy is only indicated when bone metastases are suspected based on symptoms, not for routine staging of early disease. 1

• Standard staging includes bone biochemistry tests and CT chest/upper abdomen 1
• If bone metastases are suspected, PET/CT or PET alone are more sensitive than bone scintigraphy and should be preferred 1
• MRI can document localized bone metastases when other imaging is equivocal 1

Renal Cell Carcinoma

Bone scintigraphy is NOT recommended for routine staging—only obtain when clinical signs, symptoms, or laboratory abnormalities suggest bone involvement. 1

• Contrast-enhanced chest, abdominal, and pelvic CT is the mandatory staging modality 1
• FDG-PET is not recommended for diagnosis or staging 1

Key Clinical Indicators Warranting Bone Imaging Across All Cancers

Regardless of primary tumor type, obtain bone imaging for: 1, 2

• Localized bone pain or tenderness
• Elevated bone-specific alkaline phosphatase (B-ALP)
• Suspected pathologic fracture
• Neurologic symptoms suggesting spinal cord compression
• Clinical or laboratory signs of bone involvement

Imaging Modality Selection

When bone scan is indicated but equivocal findings are anticipated, consider PET/CT as first-line imaging instead of bone scintigraphy. 3, 2

• Bone scintigraphy has low specificity (81%) and requires confirmation with CT, MRI, or PET/CT when findings are equivocal 1, 3, 2
• PET/CT shows superior sensitivity (90%) and specificity (97%) compared to bone scan (sensitivity 86%, specificity 81%) 4
• MRI is more sensitive than bone scintigraphy for early spinal metastases and is preferred for suspected spinal cord compression 1, 2
• If PET/CT is unavailable or cost-prohibitive, order bone scintigraphy PLUS CT chest/abdomen/pelvis 3

Critical caveat: Bone scintigraphy has a false-negative rate up to 40% in low-burden disease, particularly in purely lytic lesions or multiple myeloma 5, 6

Bone Mineral Density Monitoring (Distinct from Metastasis Screening)

Patients on endocrine therapy (aromatase inhibitors for breast cancer, androgen-deprivation therapy for prostate cancer) require BMD monitoring every 1-2 years to assess fracture risk, which is separate from bone metastasis screening. 1