Short summary

The aim of the study is to develop / optimize our techniques regarding preoperative localisation of hyperfunctioning parathyroid tissue in suspected primary hyperparathyroidism. Since there is no specific tracer for parathyroid tissue, our conventional technique is building on the use of a two tracer technique with Tc-99m-pertechnetat and Tc-99m- sestamibi in combination with a non-diagnostic CT. In our study we want to compare this technique with a PET/diagnostic CT technique using the PET-tracer C-11-L-Methionin. This technique is faster to perform and gives less than half the radiation compared to our conventional study. If it is comparable or maybe even better to locate relevant parathyroid adenomas it would be an attractive alternative.

Rationale

Comparison of Tc-99m-sestamibi SPECT/ld-CT to C-11-L-Methionin PET/diagnostic-CT. Golden standard being peroperative findings of localisation and PTH-measurements, combined with histopathological findings.

The evaluation of each examination is conducted by at least two MDs, who carry out the daily description of such examinations and with at least one having senior nuclear medicine expertise and an exsperienced radiologist in regard to description of diagnostic CT. Each is blinded to the other set of images but not to other imaging modalities. Ultimately a consensus-based description of each patient is made after the evaluation of each examination is complete. The consensus-based description is consistent with answers given to the referring party. 

The evaluations are based on visual assessments regarding detection and localisation of hyperfunctioning parathyroid tissue in suspected primary hyperparathyroidism in relation to routine descriptions of the examinations. The basis of the evaluation is comprised of the following parameter;

Primary endpoint:

Detection of hyperfunctioning parathyroid tissue and evaluation of level of certainty in this detection divided into five categories.

1. Certain pathology
2. Predominantly certain pathology
3. Intermediate risk of pathology
4. Predominantly no pathology
5. No pathology

Evaluation of the imaging results is performed continuously.

Secondary endpoints:

• Localisation of hyperfunctioning parathyroid tissue, by marking on a phantomdrawing, divided into 11 regions;

1. Right kraniel
2. Right central
3. Right kaudal
4. Left kraniel
5. Left central
6. Left kaudal
7. Istmus
8. Ectopic caput
9. Ectopic collum
10. Ectopic Thorax
11. No adenoma

• The certainty by which the localisation can be pointed out or not - specified on a scale 1-5.

Description of the cohort

Our cohort consist of 60 primary hyperparathyroidism patients over 18 years of age, who prior to surgical intervention at Odense University Hospital at the department of head and neck, is referred to our department, Department of Nuclearmedicine for localization of their adenoma(s) to try to attain a surgical minimal invasive procedure and reduced risk and time at the surgical table. The patients are recruited by the endocrinology departments in Svendborg and in Odense. The aim is to recruit a total of 60 patients, interim 30 patients.

We exclude:

• Suspected secondary and tertiary hyperparathyroidism.
• Suspected Familiar hypocalciuria hypercalcemia.
• Suspected Familiar Hyperparathyroidism.
• Suspected multiple endocrine neoplasia (MEN)
• Patients treated with Lithium and / or Mimpara
• Pregnancy.
• Allergy to the tracers infused.
• Persons 18 years or younger.
• Former operation / radiotherapy towards the neck.
• If the prathyroidscintigraphy is cancelled or there is more than a forthnight between the two examniations.
• If the patient has undergone operation between the two examinations.
• If the patient is not operated within a month after completing the two examinations.
• Inhability - if the person does not speak and understand danish to a degree acceptable to participate or has cognitive problems that complicates active participation.
• If there is no signed consent to participate or the concent has been withdrawn.

Data and biological material

The data we collect consist of symptoms of the patient prior to surgery - including symptoms important to differentiate from any possible later adverse effects e.g. known comorbidity. We collect data of relevant medication and blood samples relevant for the presumed diagnose of primary hyperparathyroidism. We also collect data of scanning results i.e. localization of suspected hyperparathyroidism adenoma and how certain we are of this result.

Collaborating researchers and departments

Department of Nuclear Medicine, Odense University Hospital

• Physician Kate Rewers
• Phycisian Nick Jakobsen
• Biomedical laboratory technician Lene Børker-Rasmussen
• Associate Professor Oke Gerke
• Consultant Henrik Petersen

Department of Otolaryngology, Odense University Hospital

• Consultant Mette Bay
• Staff specialist Anders Rørbaek Madsen

Department of Endocrinology, Odense University Hospital

• Consultant Charlotte Ejersted

Department of Medicine, Odense University Hospital, Svendborg

• Consultant Tony Bill Hansen

The GCP-unit, Odense University Hospital

• GCP monitor Babara Seider
• GCP monitor Kirsten Klejs Breiting