Development and validation of a nomogram to predict parathyroid gland volume in secondary hyperparathyroidism

Secondary hyperparathyroidism (SHPT) is a common complication in dialysis patients, often requiring parathyroidectomy (PTX) when medical therapy fails. While successful PTX relies on identifying all parathyroid glands, preoperative imaging modalities have limitations in diagnosing lesions in patients with SHPT. Preoperative estimation of parathyroid gland volume could enhance surgical planning. We retrospectively analyzed 555 patients with SHPT who underwent PTX between January 2015 and May 2025. Patients were divided into training and validation sets at a 7:3 ratio. Univariable and multivariable linear regression analyses were performed to identify associations between gland volume and preoperative demographics, laboratory indicators, and imaging data. Multivariable analysis identified five independent predictors of parathyroid gland volume. Dialysis duration ( P = 0.046), serum calcium ( P < 0.001), PTH ( P < 0.001), and the number of glands detected by ultrasonography ( P = 0.003) were positively associated with gland volume, whereas serum albumin ( P < 0.001) was negatively associated. In the validation set, the model demonstrated moderate predictive performance, with a correlation coefficient of 0.455 between predicted and actual gland volumes. In addition, 61.7% of estimated values fell within a clinically acceptable 30% margin of error (P 30 ). A nomogram was constructed to visualize these predictive relationships. Preoperative clinical variables, including PTH, calcium, albumin, dialysis duration and the frequency of glands detected by ultrasound are significantly associated with parathyroid gland volume in SHPT. The model’s clinical utility for identifying missed or ectopic glands remains to be evaluated. Chinese Clinical Trial Registry, ChiCTR2500111598. This study was registered retrospectively on 03 November 2025.