Remnant Ablation Research Articles

放射性ヨウ素内用療法（アブレーション）の適応

放射性ヨウ素内用療法（アブレーション）の適応

Challenges and strategies on radioiodine treatment for differentiated thyroid carcinoma.

Radioiodine ((131)I) is considered an effective and low-risk therapeutic radionuclide for differentiated thyroid carcinoma (DTC); however, dilemmas exist in the optimization of indications, pre-treatment thyroid stimulating hormone (TSH) stimulation, dose decision, as well as in the treatment of (131)I-refractory disease. Refined strategies on (131)I treatment for DTC based on late evidence and novel insights are greatly needed. The indications of (131)I ablation continue to be refined with a better understanding of the risks and benefits. For pre-treatment TSH stimulation, recombinant human thyrotropin presents a better choice as it improves the quality of life, but is indicated only for ablation of the thyroid remnant and follow-up. Decreased doses of (131)I seem to be more appropriate in patients without gross residual disease or metastases, but maximal doses are suggested in patients with advanced disease. Imaging procedures contributing to decision-making for patients with advanced DTC also continue to be modified. As for the (131)I-refractory disease, there is a trend to increase (131)I uptake and retention by using additional therapeutic agents like kinase inhibitors with encouraging results.

Expression of Notch 1 receptor associated with tumor aggressiveness in papillary thyroid carcinoma.

AimThe aim of this study was to assess if the expression of Notch 1 receptor is associated with tumor aggressiveness in papillary thyroid carcinomas (PTCs).Patients and methodsBy searching the electronic medical record system of Xin Hua Hospital, all cases of PTC patients who underwent thyroidectomy in the hospital between 2013 and 2014 were retrieved. Then, the cases of patients who had a history of any other malignancy or whose thyroid tumor specimen was not available for assay were rejected. Finally, 68 cases of PTC patients were obtained. Formalin-fixed paraffin-embedded tissue blocks of these patients were studied by immunohistochemistry to learn the expression of Notch 1 receptor. Meanwhile, the clinical data of these patients including sex, age, size of the tumor, presence of node metastasis or distant metastasis, and presence of capsule invasion and tumor multicentricity were collected. Pearson’s chi-square test or Fisher’s exact test was used for measuring statistical differences in categorical variables. All the statistical tests were two-sided. A P-value <0.05 was considered to be statistically significant.ResultsA total of 19 male and 49 female PTC patients with a mean age of 44.8±13.6 years (range 18–78 years) were studied. Notch 1 receptor expression was found in 15/68 (22%) samples of PTC. The expression of Notch 1 receptor was significantly associated with tumor size (P=0.021), distant metastasis (P=0.008), capsule invasion (P=0.001), tumor multicentricity (P=0.018), and age (P=0.033). However, the expression of Notch 1 receptor was not significantly correlated with node metastasis (P=0.096) and sex (P=0.901).ConclusionThe expression of Notch 1 receptor is associated with tumor aggressiveness in PTC, and may be used as a molecular marker of tumor invasiveness in PTC. PTC patients who show positive expression of Notch 1 receptor may benefit from radioiodine remnant ablation.

Treatment and outcome of 32 patients with distant metastases of Hürthle cell thyroid carcinoma: a single-institution experience.

BackgroundIt is generally believed that patients with Hürthle cell thyroid carcinoma (HCTC) have a poor prognosis. Furthermore, distant metastases represent the most frequent cause of thyroid cancer-related death of patients with HCTC. The aim of this study was to report the treatment and outcomes of patients with distant metastases.MethodsAltogether 108 patients were treated for HCTC from 1972 to 2011 in our tertiary center and 32 patients (19 females, 13 males; median age 64.5 years) had either initially proven metastatic disease (N = 12) or distant progression of HCTC after initial treatment (N = 20). Patients with metastases were followed for 1–226 (median 77) months. Data were collected on the patients’ gender and age, extent of their disease, morphologic characteristics, therapy, outcome, and survival rate. Statistical correlation between possible prognostic factors and cause-specific survival from time of detection of metastases was analyzed by univariate analysis and log-rank test.ResultsThe most common were lung metastases, followed by bone, mediastinum, kidney, and liver in 24, 8, 2, 1, and 1 case, respectively. Total thyroidectomy, lobectomy, subtotal thyroidectomy and neck dissection were performed in 19, 10, 3, and 7 patients, respectively. Radioiodine (RAI) ablation of thyroid remnant was performed in 30 patients, while 20 of them had RAI therapy (median 4 times). RAI uptake in metastases was present in 16 patients and ranged from 0.05 % to 12 %. Chemotherapy was used in 13 patients and external beam radiotherapy in 19 patients. Locoregional control of disease was achieved in 19/21 (90 %) cases who succumbed due to HCTC. Estimated 10-year disease-specific survival for all patients was 60 %. 10-year disease-specific survival for patients with pulmonary metastases and other sites metastases was 60 % and 62 %, respectively. 10-year disease-specific survival for patients with single organ and multiple organ metastases was 52 %, and 100 %, respectively. Estimated median disease-specific survival after the diagnosis of metastatic disease for all patients was 77 months. The median disease-specific survival after the diagnosis of metastatic disease for patients with pulmonary metastases and other sites metastases was 72 and 138 months, respectively.ConclusionsTen-year disease-specific survival for all patients with metastatic Hürthle cell thyroid carcinoma, patients with pulmonary metastases and bone metastases was 60 %, 60 % and 68 %, respectively.

Recombinant human thyrotropin-stimulated thyroglobulin level at the time of radioactive iodine ablation is an independent prognostic marker of differentiated thyroid carcinoma in the setting of prophylactic central neck dissection.

We investigated the value of the stimulated thyroglobulin (Tg) level at the time of recombinant human thyrotropin (rhTSH)-aided remnant ablation for predicting disease status 1year later in patients with DTC who underwent total thyroidectomy with central neck dissection (CND). This was a prospective observational study of 253 consecutive patients with DTC who underwent rhTSH-aided RAI ablation after total thyroidectomy and prophylactic CND. Patients with evidence of initial distant metastasis or positive Tg antibodies were excluded. We compared rhTSH-stimulated Tg level at RAI ablation according to the disease status at 1year and evaluated optimal cut-off value of rhTSH-stimulated Tg. Binary logistic regression analysis was performed to investigate the independent predictive factors for disease status 1year after ablation. Among study participants, 228 (90·1%) were considered disease free at 1year after remnant ablation. Patients with persistent or recurrent disease were more likely to be aged ≥45years, and to have N1b stage, TNM stage III or IV, and higher rhTSH-stimulated Tg level at RAI ablation. The optimal cut-off of rhTSH-stimulated Tg for predicting persistent or recurrent disease was 1·79ng/ml, with a negative predictive value of 99·5%. A serum rhTSH-stimulated Tg level ≥1·79 at the time of ablation was independently associated with persistent or recurrent disease 1year later. N1b stage tended to be associated with persistent or recurrent disease. A low stimulated serum Tg level at rhTSH-aided RAI ablation may be a favourable prognostic marker in the setting of prophylactic CND.

Diagnostic whole body scan (pre-therapy scan) in differentiated thyroid cancer: A single center community hospital experience.

Diagnostic whole body scan (pre-therapy scan) with either I-123 or I-131 (radioactive isotopes of iodine) is performed to assess the extent of thyroid cancer especially distant metastasis prior to administering the therapeutic dose of I-131. Our aim of the following study was to determine the utility of the diagnostic pre-therapy scan in the management of differentiated thyroid cancer. It was a case-control study carried out by retrospective chart review, of a randomly selected 100 patients with differentiated thyroid cancer who had followed in our community hospital over the course of 1 year. We collected data on multiple variables in the subjects - including age, gender, pre-operative size of the nodules, diagnosis, stage of the malignancy, size of the tumor, multifocality, lymphovascular invasion, dose of radioiodine used for remnant ablation, recurrence rates and persistence rates. Continuous variables were compared using the independent sample Mann-Whitney U-test whereas the Chi-square test was used for nominal variables. The mean dose of radioactive iodine administered was 97.56 (±27.98) in the pre-therapy scan group and it was 97.23 (±32.40) in the control group. There was no difference between the two groups (P - 0.45). There was also no difference in the recurrence rates between the groups (P = 1.0). There was a trend toward a higher degree of persistent cancer in the group that had the pre-therapy scans (P - 0.086). Pre-therapy scan may not affect the dose of radio-iodine I-131 used for remnant ablation of differentiated thyroid cancer and does not influence the recurrence rates. This was especially true with respect to I-131 remnant ablation for low risk tumors.

Stereotactic laser ablation of the splenium for intractable epilepsy.

Partial or complete corpus callosotomies have been applied, traditionally via open surgical or radiosurgical approaches, for the treatment of epilepsy in patients with multifocal tonic, atonic, or myoclonic seizures. Minimally invasive methods, such as MRI-guided laser interstitial thermal ablation (MTLA), are being employed to functionally remove or ablate seizure foci in the treatment of epilepsy. This therapy can achieve effectiveness similar to that of traditional resection, but with reduced morbidity compared with open surgery. Here, we present a patient with a history of prior partial corpus callosotomy who continued to suffer from medically refractory epilepsy with bisynchronous onset. We report on the utilization of laser ablation of the splenium in this patient to achieve full corpus callosotomy. Adequate ablation of the splenial remnant was confirmed by postoperative MRI imaging, and at four-month follow-up, the patient's seizure frequency had dropped more than 50%. This is the first reported instance of laser ablation of the splenium to achieve full corpus callosotomy following a previous unsuccessful anterior callosotomy in a patient with intractable generalized epilepsy.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer.

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer. The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members. The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research. We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

Papillary carcinoma thyroid with rare metastases: A case report and review

A 55-year-old female presented with a 10 years history of swelling in the front part of her neck, and a persistent headache for the past 4 months. During the course of her hospital stay, she developed right upper limb monoplegia. An examination showed that she had papillary carcinoma thyroid in an euthyroid state. Further work-up revealed a solitary pulmonary nodule on the left lower lobe, right ventricular tumor thrombus in the heart, and hemorrhagic metastases involving the left cerebral and cerebellar hemispheres. Total thyroidectomy with bilateral functional and central neck dissection was performed. Postoperatively, the patient received radioiodine ablation with I131 for lung and brain metastases, and remnant ablation for primary treatment. She has received regular follow-up care for the past 3 months.

Recombinant Human Thyroid Stimulating Hormone versus Thyroid Hormone Withdrawal for Radioactive Iodine Treatment of Differentiated Thyroid Cancer with Nodal Metastatic Disease.

Introduction. Recombinant human thyroid stimulating hormone (rhTSH) is approved for preparation of thyroid remnant ablation with radioactive iodine (RAI) in low risk patients with well differentiated thyroid cancer (DTC). We studied the safety and efficacy of rhTSH preparation for RAI treatment of thyroid cancer patients with nodal metastatic disease. Methods. A retrospective analysis was performed on 108 patients with histopathologically confirmed nodal metastatic DTC, treated with initial RAI between January 1, 2000, and December 31, 2007. Within this selected group, 31 and 42 patients were prepared for initial and all subsequent RAI treatments by either thyroid hormone withdrawal (THW) or rhTSH protocols and were followed up for at least 3 years. Results. The response to initial treatment, classified as excellent, acceptable, or incomplete, was not different between the rhTSH group (57%, 21%, and 21%, resp.) and the THW group (39%, 13%, and 48%, resp.; P = 0.052). There was no significant difference in the final clinical outcome between the groups. The rhTSH group received significantly fewer additional doses of RAI than the THW group (P = 0.03). Conclusion. In patients with nodal-positive DTC, preparation for RAI with rhTSH is a safe and efficacious alternative to THW protocol.

The Diagnostic Value of Serum TgAb in the Tg-Negative and TgAb-Positive DTC Patients after Successful Ablation

Objective: The aim of this retrospective study was to evaluate diagnostic accuracy of serum thyroglobulin antibody (TgAb) in thyroglobulin (Tg)-negative and TgAb-positive (Tg-TgAb+) patients with differentiated thyroid carcinoma (DTC). Method: We studied 341 patients with histologically confirmed DTC who had undergone remnant ablation and showed Tg-TgAb+ assessed by electrochemiluminescence immunoassay (ECLIA). The cases were divided into two groups, including recurrence group 119 cases and no evidence of disease (NED) group 222 cases. Receiver operating characteristic (ROC) curve analysis was carried out. The symmetric measures of the two diagnostic methods (the golden standard and the diagnostic standard as serum TgAb level alone) were analyzed using McNemar test and measure of agreement Kappa. Results: Serum TgAb level (1381.292 ± 1017.221) IU/ml of patients with recurrent group was significantly higher than that (125.559 ± 314.047) IU/ml of NED group (P = 0.000 0.001). The area under the ROC curve was 0.962 and its asymptotic 95% confidence interval (CI) was (0.942, 0.982) that was high statistical significance. The cut-off value of TgAb was determined and interpreted at 246.695 IU/ml with sensitivity (92.40%) and specificity (92.30%). McNemar test showed that the diagnostic results of the two methods were not significant difference (P = 0.230 > 0.05). Measure of agreement Kappa was 0.841, P = 0.000 0.001 that showed the agreement of the two diagnostic methods was significant. Conclusion: Serum TgAb is a useful tumor marker for recurrence in Tg-negative and TgAb-positive DTC patients who underwent thyroidectomy and remnant ablation. The cut-off value of TgAb is 246.695 IU/ml, that is to say, serum TgAb level upon 246.695 IU/ml may be associated with the persistence or recurrence of DTC.

Short-Term Side Effects after Radioiodine Treatment in Patients with Differentiated Thyroid Cancer.

Objectives. I-131 therapy for differentiated thyroid cancer (DTC) could induce adverse effects. The purpose of this study was to report and analyze symptoms after I-131 treatment within the hospitalization and present relevant medical intervention. Methods. I-131 doses ranging from 3.7 to 9.25 GBq (100–250 mCi) were administrated for thyroid remnant ablation or treating DTC metastases. 117 patients with DTC for I-131 therapy were monitored through the video and intercommunicating with standardized questionnaire at different time points after I-131 oral administration. Adverse effects were recorded and relevant clinical factors were analyzed. Results. Among all the 117 patients, 55 cases complained of neck's pain or swelling and 79 cases presented with gastrointestinal symptoms. Pain or swelling of salivary gland occurred in 15 patients, headache and vertigo in 10, insomnia in 9, vocal cord paralysis in 6, fatigue or general malaise in 6, and foreign body sensation in 5. Body numbness and urinary symptoms were observed in only 1 case, respectively. Those side effects were related with sex, pre-I-131 treatment TSH levels, frequency of I-131 therapy, and lymph node metastases. Conclusions. Short-term side effects after I-131 therapy for DTC patients varied individually; severe symptoms were not uncommon but generally did not need emergent medical intervention.

Short-term Follow-up US Leads to Higher False-positive Results Without Detection of Structural Recurrences in PTMC.

To investigate the value of the annual follow-up neck ultrasonography (US) for postoperative surveillance in patients with papillary thyroid microcarcinoma (PTMC). This retrospective study has been approved by our institutional review board (IRB) with waiver for informed consent. A total of 375 patients diagnosed as PTMCs, who underwent total thyroidectomy with radioiodine remnant ablation were included, to identify the recurrence rate and the false-positive rate of annual ultrasound. The number, interval, and the results of follow-up US or fine needle aspiration were obtained from electronic medical records. Four (1.1%, 4/375) recurrences were found 3 years after the initial treatment, and only 1 patient (0.3%, 1/375) had a metastatic lymph node larger than 8 mm in the shortest diameter on US found 7.6 years after initial treatment with biochemical abnormalities. Cumulative risk of having at least 1 false-positive exam was 8.3% by the 8th US, and 8.1% by the 8-9 year follow-up. Cox multivariate regression showed shorter interval of follow-up US and presence of lymph node metastasis at initial surgery are independent predictors affecting the cumulative false-positive results (hazard ratio [HR], 0.60; 95% confidence interval [CI]: 0.49-0.73; P < 0.001 and HR, 2.19; 95% CI: 1.01-4.75; P = 0.048, respectively). Short-term follow-up US can result in higher cumulative false-positive results without detection of meaningful recurrences in patients with PTMCs who do not have biochemical abnormalities.

Advances in thyroglobulin assays and their impact on the management of differentiated thyroid cancers

Thyroglobulin (Tg) is a high molecular weight glycoprotein located mainly in thyroid follicles, where thyroid hormones are synthesized and stored. In patients with differentiated thyroid cancer of follicular origin, serum Tg levels become undetectable following total thyroidectomy and iodine-131 remnant ablation. It is a key biomarker to follow-up patients with differentiated thyroid cancer, in combination with neck ultrasound monitoring. The measurement of Tg in the wash-out of the needle used for fine needle aspiration biopsy is a valuable aid to the diagnosis of lymph node metastasis. The presence of anti-thyroglobulin antibodies affects reliability of Tg results measured in serum or plasma. Systematic investigation of such antibodies is required to validate any Tg assay. Elevated or rising levels of anti-thyroglobulin antibodies can in turn be used as a surrogate tumor marker of thyroid cancer. The development of second-generation Tg assay (automated, highly sensitive) has enabled significant advances in the management of differentiated thyroid cancer: early detection of persistent or recurrent disease and follow-up care simplified in low-risk patients. Testing of serum Tg can also be useful in evaluating other clinical situations such as congenital hypothyroidism, endemic goiter and thyrotoxicosis factitia.

Predictivity of stimulated serum thyroglobulin and antithyroglobulin antibodies for the efficacy of thyroid remnant ablation on patients with differentiated thyroid carcinoma

Predictivity of stimulated serum thyroglobulin and antithyroglobulin antibodies for the efficacy of thyroid remnant ablation on patients with differentiated thyroid carcinoma

Regional Variation across Canadian Centers in Radioiodine Administration for Thyroid Remnant Ablation in Well-Differentiated Thyroid Cancer Diagnosed in 2000-2010.

Background. Use of radioactive iodine (RAI) ablation has been reported to vary significantly between studies. We explored variation in RAI ablation care patterns between seven thyroid cancer treatment centers in Canada. Methods. The Canadian Collaborative Network for Cancer of the Thyroid (CANNECT) is a collaborative registry to describe and analyze patterns of care for thyroid cancer. We analyzed data from seven participating centers on RAI ablation in patients diagnosed with well-differentiated (papillary and follicular) thyroid cancer between 2000 and 2010. We compared RAI ablation protocols including indications (based on TNM staging), preparation protocols, and administered dose. We excluded patients with known distant metastases at time of RAI ablation. Results. We included 3072 patients. There were no significant differences in TNM stage over time. RAI use increased in earlier years and then declined. The fraction of patients receiving RAI varied significantly between centers, ranging between 20–85% for T1, 44–100% for T2, 58–100% for T3, and 59–100% for T4. There were significant differences in the RAI doses between centers. Finally, there was major variation in the use of thyroid hormone withdrawal or rhTSH for preparation of RAI ablation. Conclusion. Our study identified significant variation in use of RAI for ablation in patients with well-differentiated thyroid cancer both between Canadian centers and over time.

Comparison of Thyroglobulin Measurements Using Three Different Immunoassay Kits: A BRAMHS Tg-Plus RIA Kit, a BRAMHS hTg Sensitive Kryptor Kit, and a Beckman Coulter ACCESS Immunoassay Kit

BackgroundSecond-generation thyroglobulin immunometric assays (Tg-IMAs) have been developed with improved sensitivity. Our aim was to compare the diagnostic value of Tg-IMA measurements using a Kryptor (BRAHMS AG) kit (Tg-K) and an ACCESS (Beckman Coulter) kit (Tg-A) with that of the first-generation Tg measurement using a Tg-plus (BRAHMS AG) kit (Tg+).MethodsWe enrolled 82 differentiated thyroid cancer patients who underwent total thyroidectomy with radioactive iodine remnant ablation and who underwent diagnostic whole body scan using recombinant human thyroid stimulating hormone (rhTSH). The Tg+, Tg-K, and Tg-A were measured before rhTSH administration during levothyroxine treatment (suppressed Tg) from the same sample. Serum Tg+ was measured after rhTSH stimulation (stimulated Tg).ResultsSuppressed Tg+ was more significantly correlated with suppressed Tg-K (R2=0.919, P<0.001) than with suppressed Tg-A (R2=0.536, P<0.001). The optimal cut-off values of suppressed Tg+, Tg-K, and Tg-A for predicting stimulated Tg+ of 1 ng/mL were 0.3, 0.2, and 0.2 ng/mL, respectively. The sensitivity, specificity, and accuracy of suppressed Tg+ were 67%, 100%, and 90%, respectively; those of suppressed Tg-K were 83%, 90%, and 88%; those of suppressed Tg-A were 96%, 82%, and 87%, respectively. The positive predictive and negative predictive values of Tg+ were 100% and 87%, respectively; those of Tg-K were 79% and 92%; and those of Tg-A were 73% and 98%.ConclusionWe could not clearly demonstrate which kit had better diagnostic performance after comparison of first-generation Tg measurements with Tg-IMA measurements. Also, there were kit-to-kit variations between Tg-IMA kits. Suppressed Tg measured by Tg-IMA was insufficient to completely substitute for a stimulated Tg measurement.

Assessment of radioiodine therapy efficacy for treatment of differentiated thyroid cancer patients with pulmonary metastasis undetected by chest computed tomography.

Radioiodine therapy (RAI) has proven effective for the treatment of patients exhibiting differentiated thyroid cancer (DTC) with pulmonary metastases. However, the early detection of metastasis remains challenging, and various studies have reported variations in radioiodine treatment efficacy. The present study investigated whether RAI is an effective method for the treatment of DTC with pulmonary metastases undetected by computed tomography (CT). A retrospective study was performed, analyzing iodine-131 (131I) therapy in 21 DTC patients with lung metastases that were undetected by CT. All 21 patients were initially treated with radioiodine ablation of thyroid remnants. Routine chest CT was performed prior to 131I treatment without diagnostic radioiodine whole-body scanning (DxWBS), and post-therapeutic WBS was performed 3–5 days subsequent to oral administration of 131I. The overall effectiveness rate was 95.2% (20/21). The rates for complete response (CR), partial response and no response were 23.8 (5/21), 71.4 (15/21) and 4.8% (1/21), respectively. There were 12 patients with diffuse uptake, and the remaining 9 patients demonstrated focused and low uptake. The difference in CR rate between diffuse uptake and focused uptake patients was not statistically significant (P=0.123). A correlation was observed between thyroglobulin (Tg) levels and extrapulmonary metastases. All patients exhibited extrapulmonary metastases when Tg levels were >87.5 ng/ml (area under receiver operating characteristic curve, 1.0; P<0.001). Overall, DTC patients with lung metastases undetected by CT imaging responded well to 131I radiotherapy and demonstrated a positive prognosis. Serum Tg levels prior to 131I treatment may correlate with metastasis, and this may suggest a requirement for the performance of DxWBS prior to radiotherapy.

Papillary thyroid carcinomas with biochemical incomplete or indeterminate responses to initial treatment: repeat stimulated thyroglobulin assay to identify disease-free patients

Papillary thyroid cancer (PTC) patients treated with thyroidectomy and radioiodine remnant ablation (RRA) often have detectable TSH-stimulated thyroglobulin (Tg) levels without localizable disease after primary treatment. To assess the value of repeat stimulated Tg assays in these patients' follow-up, we retrospectively analyzed 86 cases followed in 5 Italian thyroid-cancer referral centers. We enrolled 86 patients with PTCs treated with total/near-total thyroidectomy plus RRA between January 1,1990 and January 31, 2006. In all cases, the initial postoperative visit revealed stimulated serum Tg ≥1ng/mL, negative Tg antibodies, and no structural evidence of disease. None received empiric radioiodine therapy. Follow-up (median: 9.6years) included neck ultrasound and basal Tg assays (yearly) and at least 1 repeat stimulated Tg assay. Of the 86 patients analyzed (initial risk: low 63%, intermediate 35%, high 2%), one (1%) had ultrasound-detected lymph node disease and persistently elevated stimulated Tg levels at 3years. In 17 (20%), imaging findings were consistently negative, but the final stimulated Tg levels was still >1ng/mL (median 2.07ng/mL, range 1.02-4.7). The other 68 (80%) appeared disease-free (persistently negative imaging findings with stimulated Tg levels ≤1ng/mL). Mean intervals between first and final stimulated Tg assays were similar (5.2 and 4.8years) in subgroups with versus without Tg normalization.Reclassification as disease-free was significantly more common when initial stimulated Tg levels were indeterminate (<10ng/mL). In unselected PTC cohorts with incomplete/indeterminate biochemical responses to thyroidectomy and RRA, periodic remeasurement of stimulated Tg allows most patients to be classified as disease-free.

A Prospective Study Showing an Excellent Response of Patients with Low-Risk Differentiated Thyroid Cancer Who Did Not Undergo Radioiodine Remnant Ablation after Total Thyroidectomy

Objectives: To prospectively evaluate the outcome of patients with low-risk papillary thyroid carcinoma treated with total thyroidectomy (TT) who did not undergo radioiodine remnant ablation (RRA). Study Design: We prospectively followed up 57 patients; 3 months after TT, thyroglobulin (Tg) assessment and neck ultrasonography (US) were performed while patients were taking <smlcap>L</smlcap>-T₄, presenting suppressed TSH. Six months after TT, patients underwent stimulated Tg testing and whole-body scan (WBS) after recombinant TSH (rhTSH). Then, 18 months after TT, the patients were evaluated by neck US and Tg under TSH between 0.5 and 2.0 mIU/ml. Two years after TT, we performed another rhTSH assessment, measuring Tg and making a WBS. The patients were then annually monitored with neck US and Tg measurement under TSH between 0.5 and 2.0 mIU/l for 36-84 months. Results: Neck US of all patients, 3 months after TT, presented no evidence of abnormal residual tissues or metastatic lymph nodes (negative neck US); at this time, the mean Tg level was 0.42 ng/ml. Six months after surgery, after rhTSH, the mean thyroid bed uptake was 1.82%, and Tg levels ranged from 0.10 to 22.30 ng/ml (mean, 2.89 ng/ml). The patients were followed up without any sign of recurrence (negative neck US and stable or decreasing Tg levels). During the ongoing follow-up, the Tg trend was stable or decreasing, independently of the initial suppressed or stimulated Tg level, or WBS uptake. Conclusions: In patients with low-risk differentiated thyroid cancer, who were operated by TT and who did not undergo RRA, an excellent response to treatment may be confirmed by annual neck US and Tg trend.