Prophylactic central lymph node dissection in differentiated thyroid cancer

Endoscopic thyroidectomy along with bilateral central neck dissection (ETBC) increases the risk of transient hypoparathyroidism for patients with thyroid carcinoma

Increasing number of patients with thyroid carcinoma, especially young female patients, prefer to choose endoscopic thyroidectomy with bilateral central neck dissection (ETBC) for perfect cosmetic effects. However, the incidence of hypoparathyroidism after ETBC has not been well studied. Ninety six patients with papillary thyroid carcinoma were enrolled. All patients, including 49 ETBC and 47 open surgery patients, underwent total thyroidectomy with bilateral central neck dissection (CND). Some patients also underwent lateral neck dissection simultaneously. The incidence of hypoparathyroidism and parathyroid hormone (PTH) level were examined. Patients in the open surgery group had more advanced lesions, with larger tumor (p = 0.000), older age (p = 0.000), and more serious local involvement. The dissection extent of the open group was significantly larger than that of the ETBC group (p = 0.006). In contrast, the ETBC group with less dissection extent showed a significantly higher incidence of transient hypoparathyroidism than the open group (59.2 vs. 29.6 %, p = 0.004). The average PTH decline of the ETBC group was significantly higher than that of the open group on postoperative day 1 (POD1) (32.1 vs. 21.6 pg/ml, p = 0.010). Furthermore, the ETBC group had a significantly higher portion of patients with a PTH <10 pg/ml on POD1 (p = 0.001). One patient in the ETBC group developed permanent hypoparathyroidism. Autotransplantation and inadvertent removal rates of parathyroid did not differ between the two groups. Although generally considered a safe method for patients with thyroid carcinoma, ETBC may increase the risk of transient hypoparathyroidism compared with conventional open surgery.

Role of prophylactic central compartment lymph node dissection in clinically N0 differentiated thyroid cancer patients: analysis of risk factors and review of modern trends

In the last years, especially thanks to a large diffusion of ultrasound-guided FNBs, a surprising increased incidence of differentiated thyroid cancer (DTC), "small" tumors and microcarcinomas have been reported in the international series. This led endocrinologists and surgeons to search for "tailored" and "less aggressive" therapeutic protocols avoiding risky morbidity and useless "overtreatment". Considering the most recent guidelines of referral endocrine societies, we analyzed the role of routine or so-called prophylactic central compartment lymph node dissection (RCLD), also considering its benefits and risks. Literature data showed that the debate is still open and the surgeons are divided between proponents and opponents of its use. Even if lymph node metastases are commonly observed, and in up to 90% of DTC cases micrometastases are reported, the impact of lymphatic involvement on long-term survival is subject to intensive research and the best indications of lymph node dissection are still controversial. Identification of prognostic factors for central compartment metastases could assist surgeons in determining whether to perform RLCD. Considering available evidence, a general agreement to definitely reserve RCLD to "high-risk" cases was observed. More clinical researches, in order to identify risk factors of meaningful predictive power and prospective long-term randomized trials, should be useful to validate this selective approach.

Surgical morbidity of cervical lymphadenectomy for thyroid cancer: A retrospective cohort study over 25 years

INTRODUCTION

Prognosis of thyroid cancer is strictly related to loco-regional metastases. Cervical lymphadenectomy has a specific oncologic role but may lead to significant increase of morbidity. Aim of the study is the analysis of surgical morbidity in cervical lymphadenectomy for thyroid cancer.

METHODS

We retrospectively analyzed 1.765 thyroid cancers operated over a period of 25 years at S. Maria University Hospital, Terni, University of Perugia, Italy. Type of lymphadenectomy, histology and complications were analysed.

RESULTS

A prevalence of differentiated and medullary cancers was observed (respectively 88% and 7.2%). Central lymphadenectomy was carried out in 425 patients, lateral modified and radical lymphadenectomy respectively in 651 and 17 cases. Following central neck dissection we observed: bilateral and unilateral temporary recurrent nerves palsy respectively of 0.7% and 3.5%, unilateral permanent palsy in 1.6% of cases, temporary and permanent hypoparathyroidism respectively in 17.6% and 4.4%. After lateral neck dissection we observed: intra and post-operative haemorrhage respectively in 2% and 0.29%, respiratory distress in 0.29%, lesions of facial nerve in 0.44%, of vagus in 0.14%, of phrenic nerve in 0.14%, of hypoglossal nerve in 0.29%, of the accessory nerve, transient in 1.34% and permanent in 0.29%, permanent lesion of cervical plexus in 0.29%, salivary fistula in 0.14% and chylous fistula in 1.04% of patients. Student's t test was used to compare groups when appliable.

CONCLUSION

Central and lateral cervical lymph node dissection are associated to severe morbidity. Correct indication, surgical expertise, high volume of patients and early multidisciplinary management of complications is the key of an acceptable balance between oncologic benefits and surgical morbidity.

Intraoperative ultrasonography is useful in surgical management of neck metastases in differentiated thyroid cancers

Differentiated thyroid carcinomas are the most common malignancies of endocrine organs. Metastases to cervical lymph nodes occur in 20-50% of cases. Recurrence and survival rates are closely related to the type of surgery performed. High-resolution ultrasonography (USG) is a sensitive imaging method used to detect occult lymph node metastases in patients with thyroid cancer. We evaluated how intraoperative USG affected surgical success. This was a retrospective study comparing two groups of patients with thyroid carcinoma who underwent cervical lymph node dissection. A total of 101 patients (33 males and 68 females) were included. Group 1 included 53 patients who underwent surgery with intraoperative USG guidance. Group 2 included 48 patients who underwent surgery without the use of USG. All patients were followed up (mean 23 months; range 5-44 months) with thyroglobulin measurements and USG evaluations. Group 1 (intraoperative USG) had a residual/recurrent tumor rate of 1.9% (1/53 patients). Group 2 had a residual/recurrent tumor rate of 12.5% (6/48 patients). A statistically significant difference appeared between the residual/recurrent tumor rates in Groups 1 and 2 (p<0.05). In addition to its classical use in diagnosis and follow-up, intraoperative use of high-resolution USG can improve surgical success and may decrease the number of residual/recurrent tumors encountered during follow-up.

The role of surgery in the current management of differentiated thyroid cancer

In the last decades, a surprising increased incidence of differentiated thyroid cancer (DTC), along with a precocious diagnosis of "small" tumors and microcarcinomas have been observed. In these cases, better oncological outcomes are expected, and a "tailored" and "less aggressive" multimodal therapeutic protocol should be considered, avoiding an unfavorable even if minimal morbidity following an "overtreatment." In order to better define the most suitable surgical approach, its benefits and risks, we discuss the role of surgery in the current management of DTCs in the light of data appeared in the literature. Even if lymph node metastases are commonly observed, and in up to 90 % of DTC cases micrometastases are reported, the impact of lymphatic involvement on long-term survival is still argument of intensive research, and indications and extension of lymph node dissection (LD) are still under debate. In particular, endocrine and neck surgeons are still divided between proponents and opponents of routine central LD (RCLD). Considering the available evidence, there is agreement about total thyroidectomy, therapeutic LD in clinically node-positive DTC patients, and RCLD in "high risk" cases. Nevertheless, indications to the best surgical treatment of clinically node-negative "low risk" patients are still subject of research. Considering on the one hand, the recent trend toward routine central lymphadenectomy, avoiding radioactive treatment, and on the other hand, the satisfactory results obtained reserving prophylactic LD to "high risk" patients, we think that further prospective randomized trials are needed to evaluate the best choice between the different surgical approaches.

Can increased tumoral vascularity be a quantitative predicting factor of lymph node metastasis in papillary thyroid microcarcinoma?

The aim of the present study was to evaluate the clinical implications of the vascular index (VI) as a predicting factor for central and lateral lymph node metastasis (LNM) in patients with papillary thyroid microcarcinoma (PTMC). From January 2011 to October 2011, 588 patients (495 females, 93 males) who were diagnosed with PTMC were included. Clinicopathologic characteristics of patients and ultrasound (US) features of the lesions including VI were evaluated retrospectively. The VI was measured with QLAB 7.0 quantification software using preoperative Doppler US images. Univariate and multivariate analysis were used to assess predictive factors of LNM. From 588 patients, 140 patients (23.8 %) had central LNM and 26 patients (4.4 %) had lateral LNM on pathologic results. The presence of lateral LNM [odds ratio (OR) 5.46; 95 % confidence interval (CI) = 2.19-13.64], bilaterality (OR 2.16; 95 % CI 1.17-4.01), and increased tumor size (OR 1.15; 95 % CI 1.04-1.28) were significant independent factors for predicting central LNM. The presence of central LNM (OR 5.58; 95 % CI 2.22-14.04), upper third location of malignancy (OR 2.50; 95 % CI 1.01-6.21), and tumor size (OR 1.34; 95 % CI 1.03-1.73) were significant independent factors for predicting lateral LNM. However, the VI was not a significant predicting factor for both central and lateral LNM. Therefore, the VI of PTMC may not be useful for predicting central and lateral LNM in patients with PTMC.

Total thyroidectomy and central lymph node dissection. Experience of a referral centre for endocrine surgery

AIM

Thyroid cancer prognosis is determined by several variables, even with extremely elevated survival rate. The most debated issues are the type of thyroidectomy and extension of lymphadenectomy. Aim of the study is the analysis of benefits of level VI lymphadenectomy associated to total thyroidectomy in the treatment of thyroid cancer.

PATIENTS AND METHODS

316 total thyroidectomy with central node dissection were carried out in the Unit of Endocrine Surgery, University of Perugia. Direct parathyroid auto-implantation was carried out if damage or accidental excision occurred. High risk patients received radioiodine treatment.

RESULTS

Lymph node metastases in the VI level were observed in 42% of cases with a significant difference (p 0.0042) of positive lymph node in level VI comparing tumor larger than 1 cm vs smaller than 1 cm. No significant differences were observed when considering difference of sex, and age. Significant difference (p 0.005) was shown when considering over 45 years old male patients with tumor larger than 1 cm vs smaller ones. The 78% of patients underwent iodine ablation after surgery. Recurrence rate in these patients was 3.2%, with no significant difference compared to not treated patients. Bilateral temporary recurrent nerves palsy were observed in 0.6% of cases, unilateral temporary recurrent nerves palsy in 3.4%, unilateral permanent palsy in 1.5%, temporary hypoparathyroidism in 17%, permanent hypoparathyroidism in 4.4%.

CONCLUSIONS

Total thyroidectomy combined to central node dissection, even in absence of risk factors and without clinical evident nodes, is the treatment of choice offering clear indications to radioiodine ablation.

Impact of prophylactic central compartment neck dissection on locoregional recurrence of differentiated thyroid cancer in clinically node-negative patients: a retrospective study of a large clinical series

BACKGROUND

In clinically node-negative patients with differentiated thyroid cancer (DTC), indications for routine central lymph node dissection (RCLD) are the subject of intensive research, and surgeons are divided between the pros and cons of this surgery. To better define the role of neck dissection in the treatment of DTC, we analyzed retrospectively the results in three centers in Italy.

METHODS

The clinical records of 752 clinically node-negative patients with DTC who underwent operative treatment between January 1998 and December 2005 in three endocrine surgery referral units were evaluated retrospectively. The complications and medium- and long-term outcomes of total thyroidectomy (TT) alone (performed in 390 patients: group A) and TT combined with bilateral RCLD (362 patients: group B) were analyzed and compared.

RESULTS

The incidence of permanent hypoparathyroidism and permanent unilateral vocal folds was 1% and 0.8% in group A and 3.6% and 1.7% in the group B, respectively. Bilateral temporary recurrent nerve palsy was observed in one of the 362 patients in group B. After a follow-up of 9.5 ± 3.5 years (mean ± SD), the locoregional recurrence rate with positive cervical lymph nodes was not substantially significantly different between the two groups.

CONCLUSION

In our series, TT combined with bilateral RCLD was associated with a greater rate of transient and permanent complications. Similar incidences of locoregional recurrence were reported in the two groups of patients. Considering the recent trend toward routine central lymphadenectomy, further studies are needed to evaluate the benefits of these different approaches.