The objective of this ongoing randomized controlled trial is to examine whether the use of intra-operative NIR(near infrared) camera can reduce the number of patients who experience transient or persistent hypoparathyroidism after total thyroidectomy and completion thyroidectomy, both in malignant and benign thyroid disease.

Patients admitted to total thyroidectomy or completion thyroidectomy is ramdomized to:

1. Intervention: NIR optic imaging assisted identification of the parathyroid glands during thyroidectomy using parathyroid gland autofluorescence.
2. Control: Conventional thyroidectomy and parathyroid identification by the surgeon.

Measurements:

PTH and ionized-Ca blood samples are collected preoperatively, within 12 hours postoperatively and at 1-, 3-, 9- and 12-months follow-up.

Anticipated 214 patients are included, all of which participate in 3 months follow-up. Only patients with persistent hypoparathyroidism at this point continue til maximum 12 months follow-up.

An interim analysis will be conducted when inclusion of anticipated 128 patients and 3 months follow-up is reached.

Inclusion Criteria:

• Able to understand patient information and to give written informed consent
• Patients admitted to either total thyroidectomy og completion thyroidectomy, both benign and malign.

Exclusion Criteria:

• Not able to understand patient information and to give written informed consent
• Previous parathyroid surgery or other parathyroid decease
• Age under 18