CaPTHUS Scoring Model in Primary Hyperparathyroidism: Can It Eliminate the Need for ioPTH Testing?

Abstract

Background The CaPTHUS model was reported to have a positive predictive value (PPV) of 100% to correctly predict single-gland disease in patients with primary hyperparathyroidism, thus obviating the need for ioPTH. We sought to apply the CaPTHUS scoring model in our patient population, and also its utility in predicting long-term biochemical cure. Methods Retrospective review of all parathyroidectomies for primary hyperparathyroidism performed at our university hospital from 2003–2012. We routinely perform ioPTH testing. Biochemical cure was defined as a normal calcium level at 6 months. Results 1421 patients met inclusion criteria: 78% of patients had a single adenoma at the time of surgery, 98% of patients had a normal serum calcium at 1 week postoperatively, and 96% of patients had a normal serum calcium level 6 months postoperatively. Using the previously described CaPTHUS scoring model, 307 (22.5%) patients had a score≥3, with a PPV of 91% for single adenoma. A CaPTHUS score≥3 had a PPV of 98% for biochemical cure at 1 week as well as at 6 months. Conclusions In our population where iOPTH is used routinely to guide use of bilateral exploration, patients with a pre-operative CaPTHUS score≥3 had good long-term biochemical cure rates. However, the model only predicted adenoma in 91% of cases. If MIP without ioPTH had been done for these patients, the cure rate would have dropped from 98% to an unacceptable 89%. Even in these patients with high CaPTHUS scores, multigland disease is present in almost 10% and ioPTH is necessary.

Primary Hyperparathyroidism - Strategy for Multigland Disease in the Era of SPECT-CT

“…Some authors have used the CaPTHUS score to predict MGD. Patients with CaPTHUS>3 are more likely to have MGD disease and ioPTH has been recommended for these patients (20). There was no correlation for MGD with gender in our study, however some studies showed a male predominance in patients under 40 years (8).…”

Predictors of multiglandular disease in primary hyperparathyroidism

“…This index consists of preoperative serum calcium and PTH levels and intraoperative parathyroid gland weight, and inherently, it cannot be used to predict MGD preoperatively.The CaPTHUS score combines the results of ultrasound, scintigraphy, serum calcium, levels of parathyroid hormone (PTH) and urinary calcium [ 10 ]. The score was found to accurately predict SGD by one group [ 11 ], whereas several other groups found it reliable only in patients with overt disease and positive imaging studies [ 7 , 12 ]. Contemporary patients with pHPT are more likely to be diagnosed with minor or no symptoms and mild disease, hence the CaPTHUS score might be less reliable in a majority of the patients.…”

Surgical Management of Normocalcemic Primary Hyperparathyroidism and the Impact of Intraoperative Parathyroid Hormone Testing on Outcome

“…1 This targeted approach supplemented with IOPTH monitoring achieves long-term cure rates of 97% to 99% for the treatment of primary hyperparathyroidism (PHPT). [3][4][5] Minimally invasive, targeted parathyroidectomies where IOPTH was not used to confirm complete hyperfunctioning gland excision can miss multigland disease (MGD), which occurs in about 15% of patients, resulting in a high operative failure rate. 6 A subset of PHPT patients is now recognized as having mild biochemical changes that nevertheless have physiologic consequences.…”