Postoperative radioactive iodine evaluation of total thyroidectomy for thyroid carcinoma: reappraisal and therapeutic implications

Thyroid carcinoma in the United Arab Emirates: perspectives and experience of a tertiary care hospital

BACKGROUND

Although the distribution of thyroid carcinoma in the Arab Gulf States has been described, no previous study has examined the characteristic clinicopathologic features of thyroid carcinoma cases in the United Arab Emirates.

METHODS

The medical records of 135 patients with thyroid carcinoma diagnosed over a 15-year period (1991-2005) at Tawam Hospital, the national referral oncology center in the UAE, were retrospectively studied and the cases classified according to the histologic classification of the World Health Organization (WHO).

RESULTS

Seventy-eight patients (58%) were diagnosed before the age of 45 years with an overall peak incidence in the fourth and fifth decades. The female to male ratio was 2.4:1. Eighty-four percent had papillary thyroid carcinoma (PTC), while follicular thyroid carcinoma (FTC), anaplastic thyroid carcinoma and medullary carcinoma comprised 14%, 1.4% and 0.6%, respectively. The conventional classical variant of papillary carcinoma was the most common type. Three-quarters of the papillary carcinomas presented as multinodular goiter, while one-fifth presented as a solitary thyroid nodule. Minimal invasive follicular carcinoma was the most common variant of follicular carcinoma.

CONCLUSION

Thyroid carcinoma in the United Arab Emirates seems to be more common among females and female gender may be a risk factor. Age < 45 years can be considered an important prognostic factor as well as a possible risk factor. PTC predominates the histologic pattern of thyroid carcinoma, which is usually associated with an iodide-sufficient area.

Contemporary management of differentiated thyroid carcinoma

This article reviews the recent changes affecting the care of patients with well-differentiated thyroid carcinoma. The impacts of positron emission tomographic imaging, recombinant human thyroid stimulating hormone,and current surgical management standards are discussed.

Efficacy of i131 ablation therapy using different doses as determined by postoperative thyroid scan uptake in patients with differentiated thyroid cancer

PURPOSE

The optimal dose of I(131) for ablation of functioning residual thyroid tissue after surgery is controversial. The current study was conducted to determine the optimal dose of I(131) for remnant postoperative ablation. A review of the literature is included.

METHODS AND MATERIALS

A total of 238 patients with papillary and follicular carcinoma were treated with I(131) for ablation of a postoperative thyroid remnant. The I(131) dose was based on the 24-h percentage of neck uptake in the postoperative thyroid scans. Patients with < 5% uptake received a median of 85 mCi; 6-10% uptake, a median of 80 mCi; 11-15% uptake, a median of 60 mCi; 16-20% uptake, a median of 50 mCi; and > or =21% uptake, a median of 30 mCi. The ablation results were compared with the prognostic factors.

RESULTS

Complete ablation was observed in 40 (92%) of 43 patients receiving 85 mCi, in 31 (94%) of 33 who received 80 mCi, in 39 (95%) of 41 who received 60 mCi, in 51 (93%) of 55 who received 50 mCi, in 37 (94%) of 39 who received 30 mCi, and in 18 (96%) of 19 who received 30 mCi. The overall successful ablation rate was 94% (95% confidence interval, 89-100%).

CONCLUSION

Our findings suggest that patients with differentiated thyroid cancer can be treated with doses of I(131) according to the percentage of neck uptake of postoperative total body scan, with high complete ablation rates, without exposing patients to higher dose levels of I(131).

Surgical Treatment of Thyroid Cancers With Concurrent Graves Disease

BACKGROUND

Thyroid cancers with concurrent Graves disease are relatively rare. Accordingly, the natural history and optimal surgical treatment of thyroid cancers with Graves disease are controversial.

METHODS

Sixty-one thyroid cancers with concurrent Graves disease were retrospectively reviewed. Histopathologic diagnoses included 58 papillary thyroid carcinomas (95.1%), 1 follicular carcinoma (1.6%), 1 medullary carcinoma (1.6%), and 1 Hürthle cell carcinoma (1.6%).

RESULTS

The sample included 54 females and seven males. Subjects' ages ranged from 20 to 73 years (mean +/- SD, 35.9 +/- 10.6 years; median, 37 years). Average tumor size was 10.7 +/- 15.9 mm (range, 1-70 mm). Forty-nine tumors (80.3%) were 10 mm or smaller. Surgical procedures included subtotal thyroidectomy (40 patients), total thyroidectomy (16 patients), total thyroidectomy plus neck dissection (2 patients), near-total thyroidectomy (1 patient), and lobectomy with contralateral subtotal lobectomy (1 patient). Thirty-seven patients (60.7%) underwent postoperative 131I ablation for thyroid remnant. Neck lymph node metastases occurred in three patients and lung metastases in two patients. Patients who developed metastases were younger and had significantly larger tumors and higher pretreatment serum T3 level than those who did not develop metastases. No deaths occurred during the 6.2 +/- 4.1 year follow-up period (range, 1 year and 2 months to 18 years and 11 months).

CONCLUSIONS

Most thyroid cancers with concurrent Graves disease were 10 mm or smaller. Subtotal thyroidectomy is adequate for patients with Graves disease with concurrent carcinoma 10 mm or smaller.

Video-assisted thyroidectomy for papillary thyroid carcinoma

BACKGROUND

In patients with small papillary thyroid carcinomas (PTC), we evaluated the operative feasibility and safety of video-assisted thyroidectomy (VAT) and the completeness of the surgical resection.

METHODS

Video-assisted thyroidectomy was attempted in 24 patients with thyroid malignancy. Total thyroid resection for PTC was achieved completely by VAT in 20 of them, who were included in this study.

RESULTS

In this study, 12 total thyroidectomies and 8 lobectomies followed by completion thyroidectomies were performed. Eight patients also underwent central neck lymph node dissection. Mean postoperative serum thyroglobulin was 0.2 ng/ml for patients receiving LT4 suppressive treatment and 4.2 ng/ml for patients after LT4 withdrawal. Postoperative ultrasonography showed no residual thyroid tissue. The mean radioiodine uptake at postoperative scintiscan was 2.2%.

CONCLUSIONS

In the case of PTC, VAT is feasible and safe. The completeness of the surgical resection seems comparable with that reported for conventional surgery. Nevertheless, larger series and longer follow-up evaluation are necessary for definitive conclusions to be drawn about its oncologic validity.

Minimally invasive video-assisted thyroidectomy for papillary carcinoma: a prospective study of its completeness

BACKGROUND

The effectiveness of minimally invasive video-assisted thyroidectomy (MIVAT) in papillary thyroid carcinoma is still debated. Some are concerned about this procedure in patients with thyroid cancer. This prospective study aimed to demonstrate that near-total thyroidectomy can be performed by MIVAT with similar results compared with open thyroidectomy.

METHODS

A total of 33 patients with a thyroid nodule proven to be a papillary thyroid carcinoma underwent a near-total thyroidectomy. They were randomly assigned to group A (n = 16) or group B (n = 17) who were treated either by MIVAT or conventional near-total thyroidectomy, respectively. Iodine-131 thyroid bed uptake and serum thyroglobulin were measured 1 month after operation. Data were analyzed by unpaired t test and Mann-Whitney statistic methods.

RESULTS

. Mean iodine-131 uptake was 5.1 +/- 4.9% in group A and 4.6 +/- 6.7% in group B. Mean thyroglobulin serum levels were 5.3 +/- 5.8 ng/mL in group A and 7.6 +/- 21.7 ng/mL in group B. The differences were not statistically significant.

CONCLUSIONS

The results of this study showed that the completeness obtained with MIVAT is similar to that obtained with open thyroidectomy, with the great advantage of a minimal neck wound. No conclusions can be drawn in terms of influence of MIVAT on the outcome of the patients with small papillary thyroid carcinoma.

Prognostic factors in differentiated thyroid carcinoma: a multivariate analysis of 234 consecutive patients

BACKGROUND AND OBJECTIVES

The clinical characteristics and patient outcome of a group of patients treated for differentiated thyroid carcinoma (DTC) were analyzed in order to assess the relative influence of different prognostic factors.

MATERIALS AND METHODS

We retrospectively reviewed data about sex, age, size and histologic behavior of the tumor, extrathyroid extension of the tumor, lymph node status, distant metastasis at diagnosis, surgical procedures, and overall survival from 234 patients treated for DTC. Data were submitted to a statistical analysis.

RESULTS

Using a univariate analysis, we found that survival rates were significantly influenced by age (P = 0.0001), size (P = 0.018), extrathyroidal extension (P = 0.000001), lymph node involvement (P = 0.03), and distant metastases (P = 0.049). Age and size were independent prognostic factors at multivariate analysis (t = 2.694 and t = 2.443, respectively).

CONCLUSIONS

On the basis of our results and of a review of the literature, we conclude that total thyroidectomy is the treatment of choice in DTC, except for small (<1 cm) papillary carcinoma, that could be treated by lobectomy plus isthmectomy, while lymphadenectomy is indicated only in case of macroscopic involvement.

Management of thyroid carcinoma with radioactive 131I

PURPOSE

To evaluate the role of radioactive 131I in the management of patients with well differentiated carcinoma of the thyroid.

METHODS AND MATERIALS

Between 1965 and 1995, a total of 117 patients with well-differentiated carcinoma of the thyroid underwent either lobectomy or thyroidectomy followed by 100-150 mCi of 131I.

RESULTS

With a median follow-up of 8 years, only four patients (3%) developed a recurrence of their disease. The 5-year actuarial survival was 97% with a 10-year survival of 91%. There were no severe side effects noted after 131I therapy.

CONCLUSIONS

Radioactive 131I is a safe and effective procedure for the majority of patients with well-differentiated thyroid carcinoma. We currently recommend that all patients undergo a subtotal or total thyroidectomy followed by 131I thyroid scanning approximately 4 weeks after surgery. If the thyroid scan shows no residual uptake and all disease is confined to the thyroid, we recommend following patients with annual thyroid scans and serum thyroglobulin levels. If there is any residual uptake detected in the neck or if the tumor extends beyond the thyroid, we recommend routine thyroid ablation of 100-150 mCi of radioactive 131I.

Completion thyroidectomy for differentiated thyroid carcinoma

Completion thyroidectomy is defined as the surgical removal of the remnant thyroid tissue following procedures less than total or near-total thyroidectomy. The extent of surgical management for differentiated thyroid carcinoma (DTC) is controversial. Although some authors advocate subtotal thyroidectomy with lower complication rates, total or near-total thyroidectomy and completion thyroidectomy have been defended by others because of the improved survival and lower morbidity that is comparable with subtotal thyroidectomy. In this study, the incidence of residual tumor and surgical complication rates in patients who underwent completion thyroidectomy were investigated. The medical records of 165 patients undergoing completion thyroidectomy for DTC were reviewed. Seventy-seven (46.6%) of these patients were found to have residual tumor in the remaining thyroid tissue. Anaplastic transformation developed in two of these patients. Permanent bilateral recurrent laryngeal nerve palsy occurred in three patients, and permanent hypoparathyroidism was seen in one patient. We recommend completion thyroidectomy as an efficient and safe method of surgical treatment with a low complication rate for DTC.

Therapeutic implications of prognostic factors in differentiated carcinoma of the thyroid gland

Differentiated thyroid carcinoma is a relatively indolent disease. Despite the usually favorable prognosis, differentiated thyroid cancer is fatal in some patients. In the past, treatment strategies were often based upon incomplete knowledge or inaccurate assumptions regarding the significance of the presenting characteristics of the tumor and patient. More recently, several large retrospective reviews have analyzed various presenting factors and have identified those that have prognostic significance and those that do not. Significant prognostic factors are age, primary tumor size, histology, grade, local tumor extension, and M stage. N stage appears to be a significant factor in older patients but not in younger patients. Gender, focality, and a history of prior irradiation are not significant prognostic factors. Using this knowledge, patients can be grouped into low, intermediate, and high risk groups. Prognostic factor and risk group analysis has facilitated the development of more rational treatment algorithms. Low risk patients can usually be treated with lobectomy and suppression therapy. For high risk patients, total thyroidectomy and adjuvant radioiodine is advocated. Treatment for patients in the intermediate risk group should be individualized. Prognostic factor and risk group analysis makes a selective approach to differentiated thyroid cancer possible. Such an approach can spare many patients the morbidity and expense of unnecessarily aggressive treatment without compromising outcome.