However, other studies report similar or improved sensitivity of dual-tracer methods (either pertechnetate or I-123, plus sestamibi) over dual-phase sestamibi when utilizing a planar technique [45,54,64,65]. Sestamibi Scan and Pertechnetate Thyroid Scan with SPECT or SPECT/CT Neck Although there are a number of variations in the timing of the SPECT or SPECT/CT acquisition (ie, early, delayed, or both), it is generally accepted that the greater contrast resolution of SPECT or SPECT/CT over planar imaging provides more precise anatomic localization of parathyroid adenomas [68,69]. The addition of a pertechnetate thyroid scan may further improve localization: in a study of 268 patients, planar pertechnetate subtraction in combination with a dual-phase sestamibi scan with SPECT/CT outperformed the dual-phase sestamibi SPECT/CT alone, increasing sensitivity to 93% and PPV to 96% compared with 88% and 92%, respectively [83]. In patients with concomitant thyroid disease, the addition of CT to a dual-tracer sestamibi and pertechnetate SPECT scan increases sensitivity from 80% to 94% [84]. US Parathyroid US of the parathyroid glands is widely utilized as the initial imaging study in PHPT. Both the American Head and Neck Society Endocrine Surgery Section and the American Association of Endocrine Surgeons deem US to be the preferred initial localization study in patients with PHPT, noting the advantage of concomitant thyroid evaluation [2,8]. A 2012 meta-analysis of 19 studies evaluating US in patients with PHPT revealed a pooled sensitivity of 76% and PPV of 93% [70]. A subsequent 2017 meta-analysis of 12 studies (with few studies also included from the 2012 meta-analysis) revealed a pooled sensitivity of 80% [85]. However, the range of sensitivities reported in the literature varies widely. For example, a study of 604 patients comparing US, scintigraphy, and 4-D CT reported a sensitivity of 59% for US [31], with other smaller studies reporting US sensitivities ranging from 44% to 97% [18,20,58,86-90].
Parathyroid Adenoma. However, other studies report similar or improved sensitivity of dual-tracer methods (either pertechnetate or I-123, plus sestamibi) over dual-phase sestamibi when utilizing a planar technique [45,54,64,65]. Sestamibi Scan and Pertechnetate Thyroid Scan with SPECT or SPECT/CT Neck Although there are a number of variations in the timing of the SPECT or SPECT/CT acquisition (ie, early, delayed, or both), it is generally accepted that the greater contrast resolution of SPECT or SPECT/CT over planar imaging provides more precise anatomic localization of parathyroid adenomas [68,69]. The addition of a pertechnetate thyroid scan may further improve localization: in a study of 268 patients, planar pertechnetate subtraction in combination with a dual-phase sestamibi scan with SPECT/CT outperformed the dual-phase sestamibi SPECT/CT alone, increasing sensitivity to 93% and PPV to 96% compared with 88% and 92%, respectively [83]. In patients with concomitant thyroid disease, the addition of CT to a dual-tracer sestamibi and pertechnetate SPECT scan increases sensitivity from 80% to 94% [84]. US Parathyroid US of the parathyroid glands is widely utilized as the initial imaging study in PHPT. Both the American Head and Neck Society Endocrine Surgery Section and the American Association of Endocrine Surgeons deem US to be the preferred initial localization study in patients with PHPT, noting the advantage of concomitant thyroid evaluation [2,8]. A 2012 meta-analysis of 19 studies evaluating US in patients with PHPT revealed a pooled sensitivity of 76% and PPV of 93% [70]. A subsequent 2017 meta-analysis of 12 studies (with few studies also included from the 2012 meta-analysis) revealed a pooled sensitivity of 80% [85]. However, the range of sensitivities reported in the literature varies widely. For example, a study of 604 patients comparing US, scintigraphy, and 4-D CT reported a sensitivity of 59% for US [31], with other smaller studies reporting US sensitivities ranging from 44% to 97% [18,20,58,86-90].