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This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Hesse, M. Articles by Demonceau, G. PubMed Articles by Hesse, M. Articles by Demonceau, G.

Parathyroid detection by pinhole SPECT (PHS)

¹ St Elisabeth, Zottegem, Belgium; ² St Luc, Bouge, Belgium; ³ University of Louvain, Bruxelles, Belgium

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Objectives: We evaluate the feasibility of the detection of abnormal parathyroid by Pinhole SPECT and dedicated software.

Methods: Two acquisition methods were considered: the dual time Tc-99m-MIBI and the dual isotope Tc-99m-MIBI/I-123 methods. This last one was validated using small sources, ranging from 25 to 500 µl, stuck on the posterior wall of thyroid phantoms. The specific activities of the sources equal the thyroid ones and were closed to the clinical conditions. Various circular orbits (between 120° and 360°) were tested. Furthermore, 8 patients with hyperparathyroidism underwent both acquisition methods in one session. The Tc-99m-MIBI was injected 3 hours after the I-123. Pinhole planar and SPECT in dual isotope were performed 20' later and repeated 90’ after. The PHS software uses an OSEM reconstruction algorithm and adaptive filters, and enables the comparison of the reconstructed images by subtraction and/or ROIs drawing.

Results: On phantoms, the smallest volume (between 25 and 50 µL) can be detected with a 240° orbit. If the camera doesn’t allow it, a 180° orbit remains a valuable option. For 3 of the 8 patients, the I-123 images were not conclusive, in planar and in SPECT acquisitions as well, due to a pathological low uptake. On the remaining 5 patients, the detection was clearly improved by the SPECT images compared to the planar ones. The dual isotope method was slightly superior to the Tc-99m-MIBI dual time. All the adenomas (down to 100 µl) were detected, as proved by the post surgery parathormone levels.

Conclusions: The PHS acquisitions are thus, on this preliminary study, superior to the planar images for the detection of abnormal parathyroid. Dual isotope and dual time methods are both feasible. Except at very low I-123 uptake, the dual isotope method seems slightly more sensitive.

This Article Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Hesse, M. Articles by Demonceau, G. PubMed Articles by Hesse, M. Articles by Demonceau, G.