%0 Journal Article
%T Comparison of Five Parathyroid Scintigraphic Protocols
%A Virpi Tunninen
%A Pekka Varjo
%A Jukka Schildt
%A Aapo Ahonen
%A Tomi Kauppinen
%A Irina Lisinen
%A Anu Holm
%A Hannu Eskola
%A Marko SeppŁżnen
%J International Journal of Molecular Imaging
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/921260
%X Objectives. We compared five parathyroid scintigraphy protocols in patients with primary (pHPT) and secondary hyperparathyroidism (sHPT) and studied the interobserver agreement. The dual-tracer method ( c-sestamibi/123I) was used with three acquisition techniques (parallel-hole planar, pinhole planar, and SPECT/CT). The single-tracer method ( c-sestamibi) was used with two acquisition techniques (double-phase parallel-hole planar, and SPECT/CT). Thus five protocols were used, resulting in five sets of images. Materials and Methods. Image sets of 51 patients were retrospectively graded by four experienced nuclear medicine physicians. The final study group consisted of 24 patients (21 pHPT, 3 sHPT) who had been operated upon. Surgical and histopathologic findings were used as the standard of comparison. Results. Thirty abnormal parathyroid glands were found in 24 patients. The sensitivities of the dual-tracer method (76.7¨C80.0%) were similar ( ). The sensitivities of the single-tracer method (13.3¨C31.6%) were similar ( ). All differences in sensitivity between these two methods were statistically significant ( ). The interobserver agreement was good. Conclusion. This study indicates that any dual-tracer protocol with c-sestamibi and 123I is superior for enlarged parathyroid gland localization when compared with single-tracer protocols using c-sestamibi alone. The parathyroid scintigraphy was found to be independent of the reporter. 1. Introduction c-methoxyisobutylisonitrile ( c-sestamibi), first introduced by Coakley and coworkers as a parathyroid imaging agent in 1989 [1], is the imaging agent of choice for parathyroid scintigraphy (PS) [2]. Unfortunately, c-sestamibi is not a specific tracer for parathyroid tissue but is taken up by adjacent thyroid tissue. This problem can be overcome by using either a single-tracer (double phase) or a dual-tracer method. In the single tracer method, it is assumed that thyroid and parathyroid tissues have different washout kinetics for c-sestamibi [3]. By acquiring images in the early and late phases, the focally increasing uptake will reveal hyperfunctioning parathyroid tissue. In the dual-tracer method, c-sestamibi is used combined with 123I or c-pertechnetate, which are taken up by the thyroid gland only. Subtracting the thyroid image from the c-sestamibi image provides visualization of the parathyroid tissue alone [4]. With both single-tracer and dual-tracer methods, several acquisition techniques can be used (i.e., planar acquisitions with parallel-hole or pinhole collimators and SPECT or SPECT/CT), and several
%U http://www.hindawi.com/journals/ijmi/2013/921260/