The role of prophylactic modified neck dissection in papillary thyroid cancer

About 40 years ago, there was a substantial difference between Western countries and Japan in how papillary thyroid cancer (PTC) was managed (Figure 1). Most surgeons in Western countries totally eradicated the thyroid tissue using either surgery or radioiodine, but in Japan hemithyroidectomy or subtotal thyroidectomy were considerably more common. Radioiodine is strictly regulated by law in Japan. Moreover, there is a well-developed network between the thyroid gland and neck lymph nodes (LNs). For decades, therefore, most of Japan’s thyroid surgeons used either therapeutic or prophylactic central LN dissection (p-CND) and prophylactic modified lateral neck LN dissection (p-MND) to treat PTC (1). Western thyroid surgeons, however, used only therapeutic central or lateral LN dissection.