Abstract Background Post-surgical hypoparathyroidism (PoSH) after thyroid surgery has significant short- and long-term morbidity. Near-infrared fluorescence (NIRF) imaging has potential in reducing PoSH incidence. Methods A seamless phase II/III (IDEAL 2a-3), unblinded, parallel-group, multicentre RCT was performed in UK NHS patients planned to undergo a total or completion thyroidectomy. Participants were randomised 1:1 to thyroidectomy with NIRF and indocyanine green (NIRF+ICG), or standard thyroidectomy (SC). Operations were performed according to a surgical manual informed by an embedded process evaluation. NIFTy incorporated a phase II analysis using a surrogate primary outcome (1-day hypocalcaemia) to determine early futility of NIRF+ICG, and phase III assessment of the primary outcome of PoSH incidence at 6 months post-surgery. Secondary outcomes included parathyroid hormone levels (key secondary), protracted hypoparathyroidism, hypercalcaemia, complications, length of stay, readmissions and patient reported quality-of-life. Results In the phase II analysis, 1-day hypocalcaemia was evaluable in 208/220 patients, occurring in 13/104 (NIRF+ICG) and 17/104 (SC), which demonstrated futility of NIRF+ICG (OR (one-sided 80% CI): 0.734 (0,1.027), p=0.219). After trial closure and follow-up, 6-month PoSH was evaluable in 219/252 randomised participants and occurred in 20/107 (NIRF+ICG) and 14/112 (SC) (OR (95% CI) 0.682 (0.317,1.468)). Safety profiles were similar between arms. Conclusions The NIFTY phase II analysis showed that NIRF+ICG was extremely unlikely to demonstrate a significant difference in 6-month PoSH incidence if the trial continued. Detailed trial results, including secondary analyses, will be presented.
Balasubramanian et al. (Fri,) studied this question.