Secondary Hyperparathyroidism
Melissa Newman, Student NMT, Medical College of Georgia, Radiologic Sciences.
Rocco Cuteri, Radiology Supervisor
Cherry Lim, CNMT, Aiken Regional Medical Center, Aiken, S.C.
Mary Anne Owen, M.H.E., RT(N) Program Director, Nuclear Medicine Technology, Medical College of Georgia
NM Technologists' Concerns
Findings: Anterior head, neck and upper chest (excluding the heart) images were obtained approximately 15 minutes after administration of [25 mCi of 99mTc-Sestamibi] via intravenous injection, for immediate static views of the parathyroid glands, and then 2-hour delay images were obtained of the same anatomic regions. In the immediate view, there is normal uptake in the thyroid, parathyroid, and salivary glands. In the delay view, there is incomplete clearance and abnormal tracer uptake in the lower right and left parathyroid glands, with the right lower gland having the heaviest tracer accumulation. Since two parathyroid glands on opposite thyroid lobes failed to clear, the hyperparathyroidsm was confirmed and is indicative of parathyroid hyperplasia rather than adenoma [which is indicated by unilateral residual focal activity].
Clinical History: The patient is a 56-year-old black male who was admitted into the hospital for pulmonary edema. He has end-stage renal disease secondary to hypertension. He underwent chronic dialysis in 1987 and than had a cadaveric kidney transplant in 1993, which was slowly rejected. In 1994, the patient had the transplanted kidney removed, and he was then placed on hemodialysis. Upon arrival to the emergency room, it was discovered that the patient missed his dialysis. Therefore, his main complaints consisted of shortness of breath and severe cramping due to central fluid overload (radiography concluded pulmonary edema). He also complained of abdominal pain, nausea, and muscle weakness. In addition, the patient had excessively elevated PTH levels (over 200 pg/ml; normal levels: 12-72 pg/ml), and the administration of vitamin D3 failed to lower the PTH level. Therefore, the patient was referred to the Nuclear Medicine Department in order to evaluate for hyperparathyroidism and localize the overactive parathyroid gland(s).
Procedure:
Radiopharmaceutical: 25 mCi 99mTc-Sestamibi
Pt. Prep: (1) Verify correct patient (2) Take patient history (3) Explain Procedure with emphasis on importance of staying immobile during imaging.
Imaging: For Dual-phase imaging (immediate and delay images), patient supine with head tilted upward with [neck] hyper extended. May tape head to table to minimize movement.
Instrumentation and Views: LEAP Collimator, 256X256 matrix (magnification 2, 1 frame at 600 sec/frame) Delay imaging at 2 hours with same parameters as the immediate image.