^99mTc-Sestamibi/¹²³I Subtraction SPECT/CT in Parathyroid Scintigraphy: Is Additional Pinhole Imaging Useful?

Area of Science:

• Nuclear Medicine
• Radiopharmaceuticals
• Medical Imaging

Background:

• Parathyroid scintigraphy (PS) is crucial for diagnosing hyperparathyroidism.
• SPECT/CT combined with subtraction imaging offers high sensitivity and specificity.
• Optimizing imaging protocols can further enhance diagnostic accuracy.

Purpose of the Study:

• To evaluate the impact of additional anterior ^99mTc-sestamibi/¹²³I pinhole imaging on the diagnostic performance of subtraction SPECT/CT in PS.
• To determine if pinhole imaging improves the visualization of parathyroid glands.

Main Methods:

• Retrospective analysis of 94 patients with primary or secondary hyperparathyroidism who underwent PS.
• Acquisition protocol included simultaneous dual-isotope subtraction SPECT/CT and planar pinhole imaging.
• Comparison of image interpretation using SPECT/CT alone versus combined SPECT/CT with pinhole imaging.

Main Results:

• Combined SPECT/CT with pinhole imaging visualized more enlarged parathyroid glands (108) compared to SPECT/CT alone (104).
• Sensitivity and specificity were marginally higher with the combined approach (97% vs. 94% and 99% vs. 98%, respectively).
• The false-positive rate decreased from 6% with SPECT/CT alone to 3% with the combined pinhole imaging.

Conclusions:

• ^99mTc-sestamibi/¹²³I subtraction SPECT/CT is an effective protocol for PS.
• Anterior pinhole imaging enhances both sensitivity and specificity, although not to a statistically significant degree.
• The addition of pinhole imaging can reduce false positives in parathyroid localization.