[99m-Tc sestamibi scintigraphy in primary hyperparathyroidism. Importance of lateral projections using a pin-hole...

99mTc-Sestamibi double-phase scintigraphy has been improved with digital and tomographic procedures as well as additional projections. Since two years ago, we have introduced additional early lateral views of neck to the conventional double-phase scintigraphy. We have tried to give anatomic data about the depth of the adenomas and to evaluate the possibility of obviating the late images of the double-phase study.

Two observers reviewed 50 studies performed for primary hyperparathyroidism in two different ways. The first one reviewed only conventional double-phase studies and the second one, with the additional report of the lateral views.

in 32/50 patients (64 %) the report of the additional lateral views and the conventional early views was enough to diagnose parathyroid adenomas. No additional lesions were observed in the late views. These views did not provide any additional useful data and could have been obviated. Four ectopic adenomas were found, 1 mediastinal and 3 in paraesophagic area; three intrathyroidal focus; all of these atypical lesions were identified by lateral pinhole views.

The performance of additional lateral projections of the parathyroids supplies additional information to the surgeon on the depth of the lesion in atypical sites and would have made it possible to obviate the late phase in more than half of the patients since this did not supply additional information to that of the early images that had reached a diagnosis.