High cardiac background activity limits 99mTc-MIBI radioguided surgery in aortopulmonary window parathyroid adenomas.
BACKGROUND
Radioguided surgery using 99m-Technetium-methoxyisobutylisonitrile (99mTc-MIBI) has been recommended for the surgical treatment of mediastinal parathyroid adenomas. However, high myocardial 99mTc-MIBI uptake may limit the feasibility of radioguided surgery in aortopulmonary window parathyroid adenoma.


METHODS
Two female patients aged 72 (#1) and 79 years (#2) with primary hyperparathyroidism caused by parathyroid adenomas in the aortopulmonary window were operated by transsternal radioguided surgery. After intravenous injection of 370 MBq 99mTc-MIBI at start of surgery, the maximum radioactive intensity (as counts per second) was measured over several body regions using a gamma probe before and after removal of the parathyroid adenoma. Relative radioactivity was calculated in relation to the measured ex vivo radioactivity of the adenoma, which was set to 1.0. Both patients were cured by uneventful removal of aortopulmonary window parathyroid adenomas of 4400 (#1) and 985 mg (#2). Biochemical cure was documented by intraoperative measurement of parathyroid hormone as well as follow-up examination. Ex vivo radioactivity over the parathyroid adenomas was 196 (#1) and 855 counts per second (#2). Before parathyroidectomy, relative radioactivity over the aortopulmonary window versus the heart was found at 1.3 versus 2.6 (#1) and 1.8 versus 4.8 (#2). After removal of the adenomas, radioactivity within the aortopulmonary window was only slightly reduced.


CONCLUSIONS
High myocardial uptake of 99mTc-MIBI limits the feasibility of radioguided surgery in aortopulmonary parathyroid adenoma.
Department of Radiology, Centre for Nuclear Medicine/PET, Haukeland University Hospital, Jonas Liesvei 65, Bergen 5021, Norway. thomas.schwarzlmueller@gmail.com.
Thomas
T
Schwarzlmüller
Katrin
K
Brauckhoff
Kristian
K
Løvås
Martin
M
Biermann
Michael
M
Brauckhoff
D000236:Adenoma / Q000000981:diagnostic imaging / Q000601:surgery*; D000368:Aged; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D010282:Parathyroid Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D016105:Parathyroidectomy / Q000379:methods*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi