Combined versus subtraction-only technique in parathyroid scintigraphy: effect on scan interpretation

Area of Science:

• Nuclear medicine
• Endocrinology
• Surgical oncology

Background:

• Parathyroidectomy is the standard treatment for primary and tertiary hyperparathyroidism.
• Preoperative localization of hyperfunctioning parathyroid tissue relies on scintigraphy techniques.
• The combined scintigraphic technique is presumed more sensitive but lacks robust evidence.

Purpose of the Study:

• To compare the diagnostic yield of combined versus subtraction-only parathyroid scintigraphy.
• To assess if the combined technique detects additional lesions missed by subtraction-only imaging.
• To evaluate the impact on patient care and workflow efficiency.

Main Methods:

• Retrospective analysis of 97 parathyroid scans (January 2012 - April 2018).
• Scans were reinterpreted by three blinded readers using both combined and subtraction-only techniques.
• McNemar discordant pairs analysis was employed to compare lesion detection.

Main Results:

• A total of 192 hyperfunctioning parathyroid lesions were identified.
• The combined technique identified only four additional lesions not detected by the subtraction-only method.
• This difference in detection was not statistically significant (P=0.125).

Conclusions:

• The combined parathyroid scintigraphic technique offers no significant advantage in lesion detection.
• Dispensing with the combined technique can improve patient convenience and departmental workflows.
• Subtraction-only scintigraphy is sufficient for preoperative localization without compromising diagnostic accuracy.