Comparing the Therapeutic Efficacy of Extended Isthmusectomy Versus Total Thyroidectomy for Isthmus Tumors of the Thyroid

Zhejiang University

Status: Not yet enrolling

Conditions: Thymectomy; Thyroid Cancer

Treatments: Procedure: Total thyroidectomy; Procedure: Extended isthmusectomy

Study type: Interventional

Funder types: Other

Identifiers

NCT07274605

2025-1245

Details and patient eligibility

About

Prospective randomized open phase III non-inferiority trial in cT1bN0N1aM0 isthmus tumors of the thyroid comparing: extended Isthmusectomy (Isthmusectomy + Central Neck Dissection)(experimental group) versus total thyroidectomy + Central Neck Dissection (reference group).

Full description

The thyroid isthmus is a narrow structure connecting the two lobes of the thyroid. Papillary carcinoma arising from this site accounts for only 1-9% of all thyroid cancers. However, due to its unique anatomical location, it is more prone to extranodal extension and bilateral lymph node metastasis, exhibiting more aggressive biological behavior. The optimal extent of surgery remains controversial: total thyroidectomy facilitates postoperative radioactive iodine therapy and monitoring but results in permanent dependence on thyroid hormone replacement and increases the risk of complications such as hypocalcemia, adversely affecting patients' quality of life. In contrast, conservative approaches like extended isthmusectomy can preserve partial thyroid function, reduce complications, and maintain a better quality of life, making them particularly suitable for low-risk patients with small tumors and no metastasis. Existing retrospective studies indicate no significant difference in recurrence rates between the two surgical approaches, though the evidence remains limited. Therefore, this study aims to conduct a prospective, multicenter, open-label, parallel-controlled, randomized trial to directly compare total thyroidectomy and extended isthmusectomy in terms of postoperative recurrence rates, quality of life, and complications, thereby providing high-quality evidence for surgical decision-making.

Enrollment: 520 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

- Age 18 years or older.

Diagnosis of low-risk differentiated thyroid cancer (papillary, follicular, or Hürthle cell carcinoma).

Unifocal tumor located in the thyroid isthmus, cT1b

No evidence of extrathyroidal extension, assessed by preoperative ultrasound.

Exclusion criteria

- Aggressive pathological subtypes (e.g., tall cell, clear cell, columnar cell, or diffuse sclerosing variants of papillary thyroid carcinoma, as well as poorly differentiated types).

cN1b.

M1

Combined with other suspicious thyroid nodules within the lobes.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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520 participants in 2 patient groups

Total thyroidectomy

Active Comparator group

Description:

Patients randomised to this arm will undergo total thyroidectomy with bilateral central compartment (level VI) neck dissection

Treatment:

Procedure: Total thyroidectomy

extended isthmusectomy

Experimental group

Description:

Patients randomised to this arm will undergo extended isthmusectomy (ensure R0 resection) with bilateral central compartment (level VI) neck dissection

Treatment:

Procedure: Extended isthmusectomy