Does near infrared fluorescence imaging reduce the risk of hypoparathyroidism after thyroid surgery?

INTERVENTION: 454 patients requiring a completion or total thyroidectomy will be randomised prior to surgery to receive surgery with near‐infrared fluorescence (NIRF) and Indocynanine Green (ICG) or as per standard care. Participants will receive total or completion thyroidectomy with or without NIRF and ICG depending on their randomised allocation. Surgery without NIRF imaging (Standard care) will be performed as part of standard care in accordance to local and national protocols and guidance. Surgery with NIRF imaging and ICG will be performed using NIRF imaging using autofluorescence and with ICG during surgery. An infrared camera will be used to detect the natural glow of the parathyroid glands under infrared light (autofluorescence). ICG will be injected later in the procedure and the infrared camera will detect glow from the dye showing the blood supply to the parathyroid glands. The use of NIRF imaging will be in accordance to the protocol developed in the qualitative research (process evaluation). Clinical assessments will be as per standard practice but participants must be reviewed at 1 days post‐operation and at 1 month and 6 months after operation. Participants will complete questionnaires designed to capture health related quality of life at baseline, 1 month and 6 months after operation. CONDITION: Near Infrared Fluorescence (NIRF) Imaging to prevent Post‐surgical Hypoparathyroidism (PoSH) after Thyroid Surgery ; Surgery PRIMARY OUTCOME: ; Phase II primary outcome: Transient hypocalcaemia, defined as any adjusted calcium of <2.1 mmol/L on the day after surgery measured using calcium and serum albumin blood values from a blood test; Phase III primary outcome: Incidence of post‐surgical hypoparathyroidism (PoSH) at 6 months post‐surgery. In accordance with the national British Association of Endocrine and Thyroid Surgeons (BAETS) definition, PoSH is defined as the need for calcium and/or vitamin D supplements to treat symptoms or maintain adjusted calcium in the low normal range (between 2.1 and 2.3 mmol/L) at 6 months after surgery, measured using medical records; INCLUSION CRITERIA: 1. Aged >=18 years 2. Able to provide written informed consent 3. Due to undergo total or completion thyroidectomy with or without central neck dissection (indications for surgery may include Graves’ disease, suspected or confirmed thyroid cancer, and goitre with compressive effects). 4. ASA <=3 5. Able and willing to comply with the terms of the protocol including participant completed questionnaires SECONDARY OUTCOME: ; Phase III secondary outcomes:; 1. Transient hypocalcaemia: measured as per the phase II primary endpoint, defined as an adjusted calcium of <2.1 mmol/L on the day after surgery; 2. Protracted hypoparathyroidism: defined as either an adjusted calcium of <2.1 mmol/L, or the need for calcium and/or vitamin D supplements to treat symptoms or maintain adjusted calcium in the low normal range (between 2.1 and 2.3 mmol/L), at 1‐month after operation measured as per the phase II and phase III primary endpoints; 3. Incidence of Intra‐operative complications measured using medical records; 4. Post‐operative complications within 6 months of operation, categorised using the Clavien‐Dindo classification, measured using medical records; 5. Length of post‐operative hospital stay calculated as the time, in days, from surgery to patient declared medically fit for discharge measured using medical records; 6. Health related quality of life will be measured using 36 item Short Form survey (SF‐36) and the Questionnaire on Hypoparathyroidism (HPQ 28) at baseline, and at 1 month and 6 months after operation.; 7. Re‐admission to hospital within 6 months of surgery, for any reason, measured using medical records; 8. Hypercalcaemia: defined as any adjusted calcium level >2.6 mmol/L occurring within 6 months of operation measured as per the phase II primary endpoint; ; Phase III mechanistic outcome:; 9. Intra‐operative decision‐making measured based on the opinions of the surgeons during the operation;