Longitudinal Bone Density During TSH Suppression in Differentiated Thyroid Cancer: A Paired PET/CT Analysis

Area of Science:

• Endocrinology
• Oncology
• Radiology

Background:

• Thyroid-stimulating hormone (TSH) suppression is crucial for differentiated thyroid cancer (DTC) management.
• TSH suppression may lead to reduced bone mineral density and osteoporosis.
• Previous research on TSH suppression and bone density has shown conflicting results.

Purpose of the Study:

• To longitudinally assess bone density changes in DTC patients undergoing TSH suppression.
• To utilize Hounsfield units from PET/CT scans for precise bone density evaluation.
• To analyze bone density in both male and female patient cohorts.

Main Methods:

• Inclusion of DTC patients with continuous TSH suppression and two PET/CT scans.
• Measurement of Hounsfield units in lumbar vertebrae (L1-L5) using CT.
• Collection of relevant laboratory parameters and patient demographics.

Main Results:

• Significant decrease in lumbar vertebral bone density observed at follow-up across all vertebrae (p < 0.05).
• Women showed a statistically significant decline in bone density at multiple lumbar levels and overall.
• Men exhibited non-significant trends towards reduced bone density.

Conclusions:

• Sustained reduction in vertebral bone density occurs during TSH suppression therapy.
• Routine bone density monitoring is advised for all DTC patients on TSH suppression.
• Risk stratification by age and suppression duration, alongside potential adjustments in TSH suppression intensity or bone-protective therapies, is recommended for high-risk individuals.