Diameter of Parathyroid Glands Measured by Computed Tomography as a Predictive Indicator for Response to Cinacalcet in Dialysis Patients with Secondary Hyperparathyroidism

Abstract

Background/Aims: Cinacalcet is one of the important treatments of secondary hyperparathyroidism (SHPT). We evaluated the role of computed tomography (CT) for parathyroid glands (PTGs) to determine the response to cinacalcet therapy in dialysis patients. Methods: In study 1, we compared the predictive cutoff values of the largest volume or diameter of PTGs on ultrasonography or CT for achievement of target intact parathyroid hormone (iPTH) level according to K/DOQI guideline after cinacalcet treatment in a single dialysis center. In study 2, the role of the cutoff diameter of PTGs on CT in predicting responsive to cinacalcet therapy was reevaluated in dialysis patients with SHPT in multiple centers. Results: In study 1, among the total population of 26 patients, the number of patients with baseline iPTH over 600 pg/mL was 16 (61%). In study 2, it was 45 (54%), among 82 patients. In study 1, the number of PTGs equal to or larger than the cutoff value (≥ 11.2 mm) on CT, not ultrasonography, was significantly higher in non-responders than in responders (p=0.038). In study 2, the proportion of patients with PTGs ≥ 11.2 mm on CT was significantly higher in non-responders than responders (p=0.003). Multivariate analysis showed that pretreatment iPTH (odds ratio [OR] 1.498, p=0.003) and the existence of enlarged PTGs on CT (OR 8.940, p=0.015) were significant clinical factors affecting the response to cinacalcet. Conclusions: The diameter of PTGs on CT could predict the response to cinacalcet in dialysis patients with SHPT.

Evidencia de hiperplasia multinodular de paratiroides en un paciente con enfermedad renal crónica

“…La gammagrafía con Sestamibi marcado con Tecnecio 99m es la ideal, y su principal característica es la persistencia de la hipercaptación en imágenes tardías (a los 120 y 180 minutos) en el territorio que comparten la glándula tiroides y paratiroides (10). Una de las características importantes de las variedades de hiperplasia multinodular o uninodular de las glándulas paratiroides y que impacta en la decisión de sospecharlas, es la baja respuesta que presentan al tratamiento con vitamina D, análogos de la vitamina D, y calcimimeticos, lo que se explica por su carácter autónomo y reducción significativa que poseen en el número de receptores para la vitamina D activa y calcio, lo que ha sido demostrado en diversos estudios (11)(12)(13)(14)(15)(16). Situación semejante ocurre cuando el número de glándulas detectadas por imágenes es mayor de uno, en condiciones inclusive cuando su volumen es menor de 1000 mm 3 (1,0 cm 3 ) (17).…”

Parathyroid Nodular Hyperplasia and Responsiveness to Drug Therapy in Renal Secondary Hyperparathyroidism: An Open Question

“…The authors reported a statistically not‐significant post‐treatment decrease of PTG volume. Finally, Hong et al compared the predictive cutoff values of the largest volume or diameter of PTG measured by ultrasonography or computed tomography for achievement of K/DOQI guideline target of PTH level after cinacalcet. In univariate and multivariate logistic analysis, baseline PTH and the existence of PTG ≥ 11.2 mm on CT significantly influenced the response to cinacalcet treatment.…”

Intraoperative intact parathyroid hormone monitoring and frozen section diagnosis are essential for successful parathyroidectomy in secondary hyperparathyroidism

“…The number of PTx decreased dramatically ( 5 , 9 ). Although calcimimetics are usually administered to treat SHPT, PTx is required in patients who do not respond to drug treatment and those who cannot tolerate calcimimetics because of drug allergies and adverse effects ( 9 – 13 ). Total PTx, transcervical thymectomy, and forearm autograft are frequently performed ( 1 , 14 ).…”