Preoperative Imaging in Renal Transplant Patients with Tertiary Hyperparathyroidism

Abstract

Background Tertiary hyperparathyroidism following kidney transplantation is most commonly characterized by 4‐gland hyperplasia, but single and double adenomatous disease has been demonstrated in this population as well. It is unknown whether preoperative imaging can assist in identifying patients who may qualify for focused surgery for adenomatous disease. Materials and methods We performed a retrospective review of our patient database from 1998–2018 for patients with tertiary hyperparathyroidism following renal transplant. Patient charts were reviewed for patient demographics, laboratory values, preoperative imaging, operative findings, pathology, and complications. Results We identified 113 patients with tertiary hyperparathyroidism following renal transplant who underwent parathyroidectomy. There were 51 females and 62 males with a mean age of 53.4 ± 13.4 years. Median preoperative calcium and PTH were 10.9 mg/dl (IQR 10.3–11.2) and 228 pg/ml (IQR 118–305). Preoperative ultrasound was performed in 60 patients. Of these, 11 (18%) were negative, 38 (63%) showed 1–2 adenomas, and 11 (18%) showed ≥ 3 adenomas. 99mTc‐sestamibi parathyroid scintigraphy was performed in 101/113 patients. Of these, 11 (11%) were negative, 62 (61%) showed 1–2 areas of discordant sestamibi uptake, and 28 (28%) showed ≥ 3 areas of discordant uptake. Ultimately, 19 (17%) patients had a single adenoma removed, 16 (14%) had 2 adenomas removed, and (69%) had multi‐gland disease. There were 26 ectopic glands found in 21 patients, 42.3% of which were identified on preoperative imaging. 94.1% of patients were eucalcemic at last follow‐up, mean (± SD) 5.8 ± 3.6 years. Adenomas that were visualized on ultrasound were larger on pathology than those non‐visualized (997 ± 120 mg (mean ± SE) vs. 388 ± 109 mg, p = 0.0003). This was also true for parathyroid scintigraphy (647 ± 41 mg vs. 355 ± 51 mg, p = 0.0001). Conclusion In patients with tertiary hyperparathyroidism, preoperative imaging can aid in predicting which patients will have 1–2 gland disease. In patients with 1–2 gland disease on congruent ultrasound and nuclear medicine imaging studies, the accuracy increases to 59%. Preoperative imaging can help identify ectopic glands. Larger adenomas are more likely to be identified on both imaging modalities.

Advances in the treatment of secondary and tertiary hyperparathyroidism

“…Ultrasonography is easy to perform but has poor sensitivity. 99mTc-MIBI single-photon emission computed tomography associated with computed tomography scintigraphy (SPECT/CT) improves the sensitivity of preoperative parathyroid localization and accurately locates ectopic parathyroid glands ( 6 ). As a result, for refractory SHPT, ultrasound combined with SPECT/CT is the best choice for preoperative localization ( 48 ), while CT and MIBI scans are effective imaging modalities for the assessment of postoperative residual parathyroid glands and prior to repeat PTX ( 49 ).…”

“…In tertiary hyperparathyroidism (THPT), long-term overstimulation of the parathyroids leads to the development of nodules due to the compensatory hyperfunction to spontaneous PTH incretion. THPT is common in patients with long-term chronic kidney disease, hemodialysis, and kidney transplantation ( 6 ). HPT can cause bone diseases ( 7 ), such as pathological fractures or skeletal deformities, cardiovascular diseases ( 8 ), and kidney stones and may also induce end-stage parathyroid cancer, although this is extremely rare ( 9 , 10 ).…”

Use of [11C]choline PET/CT for visualization of four hyperactive parathyroid glands in a patient with renal hyperparathyroidism

“…Studies have shown that preoperative planning with nuclear imaging reduces the extent of surgical resection as well as the rate of surgical failure due to missing ectopic parathyroid glands [ 4 , 5 ]. If in our case poor medical drug response should be noted, the three most hyperactive parathyroid glands would be selectively removed by the surgeon based on the choline PET imaging findings [ 6 , 7 ]. Imaging directed based surgery reduces redo-surgeries and the perioperative complication rate will be very low [ 6 ].…”