Ultrasound Patterns of Parathyroid Glands in Chronic Hemodialysis Patients with Secondary Hyperparathyroidism

Abstract

Background: The role ofparathyroid glands (PTG) ultrasonography (US) in hemodialysis patients with secondary hyperparathyroidism (SHPT) is still controversial. The present study aimed at evaluating the relationship between US findings and SHPT degree as well as therapeutic outcome. Methods: Twenty hemodialysis patients with moderate SHPT and 15 with severe SHPT underwent US to assess the PTG number, maximum longitudinal diameter (MLD), structural (1 – hypoechoic, 2 – slight heterogeneous, 3 – high heterogeneous, 4 – nodular) and vascular patterns (1 – slight, 2 – medium and 3 – high). Results: PTG number, MLD and US patterns were correlated with iPTH levels. MLD of patients with moderate or severe SHPT was 7.2 ± 2.3 and 15 ± 5.1 mm (p < 0.001). Most patients with moderate SHPT showed a single PTG with an MLD <9 mm associated with 1–2 structural and vascular pattern, whereas patients with severe SHPT exhibited more than one PTG with MLD >9 mm and 3–4 structural and vascular patterns. Thirteen patients were responders to treatment and 22 nonresponders. In nonresponders, a higher number of PTG was observed as well as higher echostructural and vascular patterns. In 14 patients who underwent parathyroidectomy, no differences were found between PTG US MLD and pathology diameter. All PTG with evidence of 3–4 structural and vascular score at ultrasound showed nodular hyperplasia at pathological examination. Conclusions: The adopted classification of US findings is correlated with SHPT degree and therapeutic outcome and might be an adjunctive predictive method useful to assess the SHPT severity and to plan the therapeutic strategy.

Usefulness of the combination of ultrasonography and 99mTc‐sestamibi scintigraphy in the preoperative evaluation of uremic secondary hyperparathyroidism

“…The PTG size was defined as the maximal longitudinal diameter (MLD) of the gland, as previously described. 33 Ultrasonography finding for each gland was defined as true positive, false positive, true negative, or false negative on the basis of the pathology results.…”

Switch from calcitriol to paricalcitol in secondary hyperparathyroidism of hemodialysis patients: Responsiveness is related to parathyroid gland size

“…Very small PTG are difficult to be detected by US, while big PTG are easily detected by US even by not so highly skilled radiologists. Variation coefficient of US measurements is very low (3.1%) as we recently demonstrated 19 . In addition, the correlation between US diameter and histology is highly significant 31 …”

“…Possibly, this is due to the well‐known negative correlation between the calcium‐sensing receptors and VDR density and the type and severity of PTG hyperplasia 20 . We studied the relationship between the MLD of the largest PTG and the therapeutic responsiveness because a strong correlation between the patterns of PTG hyperplasia and the PTG diameter has been recently demonstrated by Matsuoka et al 21 Indeed, few studies have examined the relationship between responsiveness to vitamin D or analogues and PTG size in patients with SHPT 15–23 . Fukagawa et al reported that patients with at least 1 gland >0.5 cm 3 or 1 cm in diameter were usually refractory to calcitriol pulse therapy 15 .…”

“…In the present study, the number of PTG detected by US and the maximum longitudinal diameter (MLD) of largest PTG were considered. According to our previous personal experience with calcitriol therapy, 19 the 9 mm of MLD of the largest PTG was considered the ultrasound cut off of therapeutic responsiveness. The US was repeated in 20 patients who completed 12 months of paricalcitol therapy.…”

“…Studies in uremic rats 7 and in HD patients 8 have shown that paricalcitol suppresses iPTH synthesis with smaller changes in serum levels of Ca and P. It seems that paricalcitol has a more selective activity on VDR and consequently causes less intestinal absorption and bone resorption of Ca and P. Paricalcitol has also been shown to improve survival 9 and reduce the number of hospitalization 10 . Some studies have compared the therapeutic efficacy and safety of calcitriol and paricalcitol 6,11–14 and have examined the relationship between the responsiveness to calcitriol or 22‐oxa calcitriol (Maxacalcitol) and PTG size 15–23 . Actually, these studies showed that the PTG size is the main factor conditioning vitamin D effectiveness, although none has evaluated the paricalcitol's efficacy in relation to PTG hyperplasia.…”