Great question. This gets into when a sestamibi scan should be ordered, and when it should not be. In your case, it does not look like a sestamibi scan would be helpful.

Parathyroid imaging studies are very helpful in certain situations, and completely useless in others. First, they are not used for diagnosis! The diagnosis of parathyroid disease (either primary hyperparathyroidism or secondary hyperparathyroidism) is based on lab results, not imaging. Primary hyperparathyroidism is characterized by high (or sometimes high-normal) calcium levels with non-suppressed PTH levels. Secondary hyperparathyroidism is characterized by low or normal calcium levels with elevated PTH levels. Sometimes the labs are in a gray area, with normal to high-normal calcium levels and mildly elevated PTH levels.

Your labs are falling into the gray area, but are most commonly seen with secondary hyperparathyroidism, not primary. Your calcium level is normal, and the PTH is just on the higher end of normal. This is very commonly seen in patients with absorption issues. You can get absorption issues for many reasons. A history of gastric bypass and/or chronic diarrhea are common causes that I see.

The treatment for secondary hyperparathyroidism is calcium and Vitamin D supplementation. The goal is to keep the calcium in normal range (in the 9s) and keep the PTH in a reasonable range (I aim for below 90 pg/ml). Sometimes surgery is needed for secondary hyperparathyroidism, but this is uncommon.

If surgery is not being considered, then a sestamibi scan is not necessary. Scans are only necessary prior to surgery, primarily to look for any ectopic (odd location) parathyroid tumors.