Radiofrequency Ablation to Treat Loco-Regional Recurrence of Well-Differentiated Thyroid Carcinoma

OBJECTIVE: To evaluate the efficacy of radiofrequency ablation (RFA) in the treatment of loco-regional, recurrent, and well-differentiated thyroid carcinoma. MATERIALS AND METHODS: Thirty-five recurrent well-differentiated thyroid carcinomas (RTC) in 32 patients were treated with RFA, between March 2008 and October 2011. RTCs were detected by regular follow-up ultrasound and confirmed by biopsy. All patients had fewer than 3 RTCs in the neck and were at high surgical risk or refused to undergo repeated surgery. Average number of RFA sessions were 1.3 (range 1-3). Post-RFA biopsy and ultrasound were performed. The mean follow-up period was 30 months. Pre- and post-RFA serum thyroglobulin values were evaluated. RESULTS: Thirty-one patients with 33 RTCs were treated with RFA only, whereas 1 patient with 2 RTCs was treated with RFA followed by surgery. At the last follow-up ultrasound, 31 (94%) of the 33 RTCs treated with RFA alone completely disappeared and the remaining 2 (6%) RTCs showed decreased volume. The largest diameter and volume of the 33 RTCs were markedly decreased by 93.2% (from 8.1 +/- 3.4 mm to 0.6 +/- 1.8 mm, p < 0.001) and 96.4% (from 173.9 +/- 198.7 mm3 to 6.2 +/- 27.9 mm3, p < 0.001), respectively. Twenty of the 21 RTCs evaluated with post-RFA biopsies (95%) were negative for malignancy. One (5%) showed remaining tumor that was removed surgically. The serum thyroglobulin was decreased in 19 of 26 patients (73%). Voice change developed immediately after RFA in 6 patients (19%) and was spontaneously recovered in 5 patients (83%). CONCLUSION: Radiofrequency ablation can be effective in treating loco-regional, recurrent, and well-differentiated thyroid carcinoma in patients at high surgical risk.

Radiofrequency Ablation of Benign Thyroid Nodules and Recurrent Thyroid Cancers: Consensus Statement and Recommendations

Radiofrequency ablation is a new non-surgical treatment modality for patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology has developed recommendations for the treatment of benign thyroid nodules and recurrent thyroid cancers using radiofrequency ablation. These recommendations are based on evidence from the current literature and expert consensus.

Risk Factors and Prognosis of Recurrent Thyroid Cancer / 대한내분비외과학회지

PURPOSE: Differentiated thyroid cancer is known to be one of cancers which have a favorable prognosis and long-term survival resulting from slow growth of tumor and late distant metastasis. Patients are nearly cured of thyroid cancer after first operation. But, some of those have high risk factors of recurrence. Practically it has been reported that 20% of those have recurrence of cancer and 50~60% of patients died of recurrence. We analyzed factors involving to recurrence after initial treatment, frequency and site of recurrence, disease-free interval, and results of treatment. Based on this information, we investigated therapeutics to decrease the rate of recurrence and prognostic factors to expect death. METHODS: 1803 patients were primarily operated for thyroid cancer in Kyungpook National University Hospital between 1985 and 2003. Among the cases, we reviewed the clinical records of 124 patients (6.9%) who had recurrent thyroid cancer. We analyzed the difference in frequency of recurrence on the basis of sex, age, histologic types, risk groups, and lymph node metastases when they had a first operation. The correlation between these factors and mortality rate was analyzed statistically by using Chi-square test and Fisher's exact probability test. RESULTS: Post-operative recurrence of thyroid cancer was highly observed in over 40 years old at first operation (8.4% vs. 4.9%), men (17.1% vs. 3.9%). Similarly, in the case of medullary or poorly-differentiated thyroid cancers, the groups of patients with high-risk (12.3% vs. 3.9%) or with lymph node metastases (13.5% vs. 3.7%) have high frequency of recurrence. Among the 124 patients, 53.3% cases have regional recurrence sites and 20.1% have local, 17.7% distant metastases, and 1.6% combined locoregional. The number of patients who died of recurrent cancer was 32 of 124 cases. Major cause of the death was distant metastases. In the case of 104 patients who had recurrent differentiated thyroid cancer, significant prognostic indicators of low survival rates are age greater than 45 years, neck dissection at second operation and distant metastases. CONCLUSION: In order to decrease the rate of local and regional recurrence in thyroid cancer, we conclude that complete resections of thyroid tissue and cervical lymph nodes have to be operated specially in the group with high-risk. Although adjacent organs are infiltrated, active treatment should be carried out. The treatment of most medullary or poorly-differentiated thyroid cancers which result in the death of distant metastases still remains to be studied.

Molecular Diagnosis of Recurrent Thyroid Cancer by Reverse Transcription-Polymerase Chain Reaction of Thyroglobulin Messenger Ribonucleic Acid in Peripheral Blood / 대한내분비학회지

BACKGROUND: Differentiated thyroid cancer is the most common endocrine malignancy. Despite advances in the treatment of thyroid cancer, disease recurrence and metastasis may occur in as many as 20% of patients, and so continues to pose major problems in its clinical management. Serum thyroglobulin (Tg) measurements, by immunoassay, are used to detect residual or recurrent thyroid cancer following thyroid ablation. However, the usefulness of immunoassay is limited by both the requirement for thyroid hormone withdrawal, to attain optimal test sensitivity, and interference by the antithyroglobulin antibody (Anti-Tg Ab). Recent studies have reported the clinical usefulness of reverse transcription-polymerase chain reaction (RT-PCR) detection of Tg mRNA in the peripheral blood of patients with differentiated thyroid carcinomas. We performed this study to evaluate the usefulness RT-PCR of Tg mRNA in peripheral blood of patients with thyroid carcinoma following a total thyroidectomy and radioiodine ablation therapy. METHODS: Forty cases that underwent a total thyroidectomy and radioiodine ablation therapy were included in this study. Of the 40 patients, 35 were papillary carcinomas and 5 were follicular carcinomas. Ten normal control subjects were also studied. Tg mRNA was extracted. Then RT-PCR, and nested RT-PCR, were run with specific Tg primers. Concurrently, DNA sequencing of the isolates was carried out to prove the isolates were identical to the nucleotide sequence of the Tg. RESULTS: The Tg was detected in 4 of 19 patients, with either a residual thyroid bed, or metastasis, on a 131I whole body scan and in 1 of 21 patients with a negative radioiodine scan. Surprisingly, the Tg mRNA was detected in all the patients and normal controls. CONCLUSION: From our results we can not recommend Tg mRNA, detected by RT-PCR in peripheral blood, as a tumor marker superior to that of the Tg serum level. We consider an intensive re-evaluation of the method is required before considering its clinical applications.