Scintigraphy 99mTc-sestamibi, in association ultrasound of the neck, is currently the technique of choice for the location of parathyroid adenomas in patients with hyperparathyroidism then undergo parathyroidectomy (1).
After surgery, from 2% to 7% of patients continues to have a persistence of the disease. In this case, the sensitivity of scintigraphy with MIBI in locating ectopic parathyroid glands is limited and varies from 30% to 80% (2).
Thanks to the introduction of a new method radiological, PET with 11C-methionine, it is now possible to detect the possible presence of parathyroid adenomas in patients with MIBI scintigraphy been examined (3) and is also useful for false positives. PET with 11C-methionine is a diagnostic accurate in locating the parathyroid adenomas of the neck with a sensitivity of 91%, allowing you to run parathyroidectomy focused with a reduced invasiveness of surgery, with reduction of postoperative pain and better results aesthetic (4). In addition, a method is clinically useful in patients with secondary hyperparathyroidism and tertiary. The limits of this promising method are the poor availability of the tracer, the fact that it is executed in only four centers in Italy and the high cost.
We present the cases of two patients who are diagnosed with hyperparathyroidism. They are submitted in the first instance to MIBI parathyroid scintigraphy parathyroidectomy and after removal of pathological glands. Persisting high values of PTH, patients are executed before a new scintigraphy with MIBI which is however negative and then a PET with 11C-methionine which shows accumulation of tracer in a different place not detected by scintigraphy.
Key words: PET with C-methionine; proactive approach; hyperparathyroidism