Sequential improvement in parathyroid adenoma localisation: optimising the 99m Tc-sestamibi washout study

Area of Science:

• Nuclear medicine
• Radiopharmacology
• Surgical oncology

Background:

• Preoperative localization of parathyroid adenomas is crucial for focused excision in primary hyperparathyroidism.
• Current 99m Tc-sestamibi SPECT/CT methods have limitations in accurately identifying adenoma locations.
• Improving localization can reduce complications, recovery time, and costs associated with neck exploration.

Purpose of the Study:

• To enhance the accuracy of parathyroid adenoma localization using 99m Tc-sestamibi SPECT/CT.
• To increase the number of patients eligible for focused parathyroidectomy.
• To optimize imaging protocols and technology for improved diagnostic performance.

Main Methods:

• A baseline audit of the 99m Tc-sestamibi SPECT/CT service was conducted.
• Sequential improvements included: new SPECT/CT scanners, optimized acquisition/reconstruction, and addition of arterial phase iodinated contrast.
• Adenoma location was correlated with surgical and pathology results, and test performance metrics (sensitivity, specificity, AUC) were calculated after each cycle.

Main Results:

• The final cycle (Cycle 3) showed a significant improvement: 67% confident localization, 6% failure rate, 94.7% sensitivity, 90% specificity, and an AUC of 0.99 (P < 0.001).
• Compared to baseline, sequential improvements progressively reduced localization failures and increased sensitivity.
• Reporter confidence in localization increased from 44% at baseline to 67% after all improvements.

Conclusions:

• Sequential enhancements to 99m Tc-sestamibi SPECT/CT significantly improved diagnostic performance for parathyroid adenoma localization.
• These improvements reduce localization failures and false negatives, making focused parathyroidectomy more accessible.
• Optimized SPECT/CT protocols enhance the benefits of focused excision parathyroidectomy for patients with primary hyperparathyroidism.