Efficacy and safety of parenchyma-sparing thyroidectomy for small low-risk papillary thyroid carcinoma: preliminary results from the first European prospective single-centre study

Background Thyroid lobectomy (TL) is the gold standard approach for small (<2cm) low-risk papillary thyroid carcinomas (PTC), yet it leads to postoperative hypothyroidism in approximately 60% of cases. Active surveillance or parenchyma-sparing thyroidectomy (PST) (isthmectomy or tumour enucleation) may represent conservative but safe options. This study evaluated the efficacy and safety of PST compared with TL in patients with low-risk PTC who declined active surveillance. Methods A prospective study started in December 2023. Eligible patients had PTC ≤15mm without extrathyroidal extension or lymph node metastasis, with a tumour–capsule distance of ≥2 and <10mm. All patients received comprehensive counselling and freely choose between PST and TL. The primary endpoint was structural recurrence, defined by postoperative ultrasound. Secondary endpoints included complication rate, operative time, and the need for and dosage of levothyroxine therapy. Results Sixty-three patients were enrolled: 27 (42.9%) underwent PST and 36 (57.1%) TL. Baseline and histological features did not differ between groups. No positive surgical margins or disease recurrence at 6 months were observed in both groups. Complication rate was similar between groups (3.7% vs. 5.6%; p=0.732). TL was associated with a longer operative time (40 vs. 30 minutes; p<0.001), a higher rate of levothyroxine requirement at 6 months (52.8% vs. 18.5%; p=0.005), and a higher levothyroxine dosage (72.7 vs. 65.5 μg/day; p=0.028). Conclusion PST appears safe and effective for selected patients with small, low-risk PTC and offers improved preservation of thyroid function. These preliminary findings support its potential role as a conservative surgical option.