Level VI lymph node dissection does not decrease radioiodine uptake in patients undergoing radioiodine ablation for...

Area of Science:

• Endocrinology
• Surgical Oncology
• Nuclear Medicine

Background:

• Central compartment lymph node metastases occur in about 50% of well-differentiated thyroid cancer patients.
• Level VI lymph node dissection is increasingly used to reduce recurrence rates, even without apparent nodal metastases.
• The impact of level VI dissection on radioiodine ablation effectiveness is not well-established.

Purpose of the Study:

• To investigate whether level VI lymph node dissection affects radioiodine uptake in patients with well-differentiated thyroid cancer undergoing radioiodine ablation.
• To determine if central compartment lymph node dissection influences preablation thyroglobulin levels.

Main Methods:

• Retrospective review of 277 well-differentiated thyroid cancer patients treated between 2006-2010.
• Analysis of patients who underwent total thyroidectomy with (TT + LVIND) or without (TT only) level VI lymph node dissection.
• Comparison of percent radioiodine ((131)I) uptake at 72 hours on preablation scans between the two groups.

Main Results:

• No significant difference in radioiodine uptake was observed between patients who underwent TT + LVIND (0.93%) and TT alone (1.2%) (p=0.17).
• The median number of radioactive foci in the thyroid bed was similar in both groups (p=0.64).
• Mean preablation thyroglobulin levels were comparable between the TT + LVIND group (4.0 ng/ml) and the TT group (4.7 ng/ml) (p=0.07).

Conclusions:

• Level VI lymph node dissection does not appear to reduce radioiodine uptake in well-differentiated thyroid cancer patients.
• Central neck dissection did not significantly alter preablation thyroglobulin levels.
• The routine use of level VI lymph node dissection solely to impact radioiodine ablation efficacy is not supported by this study.