SPECT-CT-guided ultrasound for parathyroid adenoma localisation - a one stop approach.

Rationale: To evaluate the accuracy of one-stop (single patient attendance) SPECT-CT-guided ultrasound (US) in the localisation of parathyroid adenomata (PTA). Secondary aims included analysing the effect of multiple PTA and concurrent thyroid disease on sensitivity. Methods: Patients with hyperparathyroidism that had undergone parathyroidectomy were identified over a 5 year period. Pathological correlation with results from pre-operative sestamibi SPECT-CT followed by targeted US of the neck was performed. The number of glands, location and presence of concurrent thyroid disease were reviewed. Results: 146 patients were included (88% single gland, 7% multigland and 5% negative explorations). The sensitivity and specificity of SPECT-CT-guided US were 83% and 96% respectively. The sensitivity was higher for single gland (87%) as compared to multigland disease (70%). The addition of ultrasound significantly increased the sensitivity of the technique (p<0.001). The presence of concurrent thyroid disease (nodules/thyroiditis) did not adversely affect sensitivity (85% CI 74.2-93.1%) compared with normal or atrophic glands (82% CI 72.3-89.7%). Conclusion: SPECT-CT guided US represents a useful means of localising PTA, thereby aiding the decision to undertake minimally-invasive or exploratory surgery. The one-stop approach offers patient convenience and enables the radiologist to use the additive benefits of both modalities to optimise localisation. The technique is less sensitive in multi-gland disease, but concurrent thyroid disease does not adversely affect sensitivity.