Predictive value of recombinant human TSH stimulation and neck ultrasonography in differentiated thyroid cancer patients

Is there an added value for whole body scan combined with stimulated thyroglobulin testing for follow-up of differentiated thyroid cancer patients?

BACKGROUND

Whole-body scan (WBS) is indicated for selected patients in the follow-up of differentiated thyroid cancer (DTC).

AIM

The aim of this study was to evaluate the incidence of positive WBS in patients with negative stimulated thyroglobulin (sTg), to define the clinical characteristics of this group, and the association with disease outcome.

METHODS

DTC patients who underwent surveillance with simultaneous sTg and WBS were included.

RESULTS

Two hundred seventy-two patients were included. Age at diagnosis was 46.5 ± 15.2 years, 79% were female. Mean duration of follow-up was 11.6 ± 6.8 years. Patients were categorised according to stimulation test results: sTg(-)/WBS(-) in 192/272 (70.6%); sTg(+) regardless of WBS results in 33/272 (12.1%); and sTg(-)/WBS(+) in 47/272 (17.3%) subjects. sTg > 10 mg/dl was considered positive. The three groups had similar demographic and pathologic characteristics. During follow-up, additional treatment was given in 77 patients (28.3%). Twelve (4.4%) developed distant metastases; 16 patients (5.8%) died. No deaths were disease-related. There was no difference in mortality rate between categories (P = 0.182). On multivariate analysis, additional treatment was associated with male gender (P = 0.046) and positive stimulation test results, either sTg (P < 0.001) or WBS (P < 0.001). Of the 47 WBS(+)/sTg(-) patients, 7(15%) were treated due to positive WBS results, including two who underwent additional surgery.

CONCLUSION

A substantial proportion of stimulation test results were discordant. There was a significant association between WBS results and administration of additional treatment. Routine WBS had additional value for a small proportion of patients with no other evidence for disease and no indication for WBS.

Radioiodine therapy reduces the frequency of circulating tumour cells in patients with differentiated thyroid cancer

OBJECTIVE

The aim of the study was the quantification of circulating tumour cells (CTCs) in differentiated thyroid cancer (DTC) patients before and 6 weeks after radioiodine therapy (RIT).

CONTEXT

Circulating tumour cells (CTCs) were described more recently in cancer patients, mostly correlating with poor outcome and advanced metastases.

DESIGN

Peripheral blood for identification and quantification of CTC before RIT or/and 6 weeks after RIT was provided by 55 DTC patients that received RIT for remnant tissue ablation.

PATIENTS

13 follicular thyroid cancer (FTC) patients, 31 papillary thyroid cancer (PTC) patients and 11 patients having the follicular variant PTC (FV-PTC) were included.

MEASUREMENTS

Peripheral blood mononuclear cells (PBMCs) were isolated and EpCAM-positive CTCs were counted by immune fluorescent staining.

RESULTS

A CTC positivity of 31.8% before RIT could be observed. Six weeks after RIT, the CTC positivity was reduced to 13.6%. Paired data at both time points of blood sampling could be gathered for n = 33 DTC patients. These patients had significantly higher CTC numbers before RIT than 6 weeks afterwards (0.27 ± 0.47 vs 0.05 ± 0.15, P = .0215). Additionally, significantly reduced CTC numbers were also demonstrated in pre-RIT CTC-positive patients (0.88 ± 0.43 vs 0.05 ± 0.16, P = .0039).

CONCLUSION

Our results indicate a reducing effect on the number of CTCs by RIT. Therefore, CTC enumeration should be considered as efficient tool for treatment monitoring during RIT.

Response to Therapy Assessment in Intermediate-Risk Thyroid Cancer Patients: Is Thyroglobulin Stimulation Required?

Introduction: The 2015 American Thyroid Association (ATA) guidelines recommend response to therapy (RTT) assessment 1-2 years after initial treatment in differentiated thyroid cancer (DTC) patients to guide thyrotropin (TSH) goals and long-term follow-up. We hypothesized that data collected during the first 2 years of follow-up may be sufficient to determine RTT without thyroglobulin (Tg) stimulation. Materials and Methods: Patients treated with total thyroidectomy and radioiodine for intermediate-risk DTC, followed for >2 years, and had sufficient follow-up data were included. Data on Tg, ultrasound, scans, and long-term outcomes were collected. Results: One-hundred twenty patients met inclusion criteria, with 68% women and mean age 55 ± 15 years. Intermediate risk was due to lymph-node involvement (72%), extrathyroidal extension (51%), vascular invasion (12%), and high-risk histology (9%). At the end of follow-up of 7 ± 4 years, 26% had persistent disease (14% biochemical, 12% structural). According to the ATA RTT system (using stimulated-Tg), 56% had excellent RTT, of whom only 2% had disease at the end of follow-up. In the "nonstimulated" system (which includes basal Tg, post-¹³¹I therapy whole-body scan (TxWBS) for assessment of residual lymph-node metastases after surgery, and structural imaging studies), 57% had excellent response, of whom none had disease at the end of follow-up. Only eight patients (7%) were classified differently due to recombinant human thyrotropin stimulation (as either excellent or indeterminate response), with no difference in predictive value, with a receiver-operator characteristic area under the curve of 0.903 with Tg-stimulation and of 0.918 without. Conclusions: In patients with no evidence of disease during the first 2 years of follow-up, the addition of stimulated-Tg adds little prognostic information. We suggest the use of excellent RTT based on basal Tg together with TxWBS and structural imaging studies.

Follow-up of differentiated thyroid cancer - what should (and what should not) be done

The treatment paradigm for thyroid cancer has shifted from a one-size-fits-all approach to more personalized protocols that range from active surveillance to total thyroidectomy followed by radioiodine remnant ablation. Accurate surveillance tools are available, but follow-up protocols vary widely between centres and clinicians, owing to the lack of clear, straightforward recommendations on the instruments and assessment schedule that health-care professionals should adopt. For most patients (that is, those who have had an excellent response to the initial treatment and have a low or intermediate risk of tumour recurrence), an infrequent assessment schedule is sufficient (such as a yearly determination of serum levels of TSH and thyroglobulin). Select patients will benefit from second-line imaging and more frequent assessments. This Review discusses the strengths and weaknesses of the surveillance tools and follow-up strategies that clinicians use as a function of the initial treatment and each patient's risk of recurrence.

Is a second recombinant human thyrotropin stimulation test useful? The value of postsurgical undetectable stimulated thyroglobulin level at the time of remnant ablation on clinical outcome

OBJECTIVE

The management of patients with differentiated thyroid cancer (DTC) has changed in recent years, and monitoring depends on the risk of persistent/recurrent disease. The objective was to assess the prognostic value of a single stimulated thyroglobulin (Tg) measured at the time of the first radioiodine therapy (Stim-Tg1), and the utility of a second stimulated Tg measurement performed 6-12 months later (Stim-Tg2). We also examined the role of neck ultrasound (US) in the early diagnosis of recurrence.

DESIGN

This was a retrospective observational cohort study conducted in a tertiary referral hospital. Of 213 evaluated patients with DTC, 169 were finally included.

METHODS

Measurement of Stim-Tg1, Stim-Tg2 and neck US.

RESULTS

Stim-Tg1 was undetectable in 71 of 169 patients (42%). All of them (71/71) continued to have negative Stim-Tg2. Seventy of 71 had an excellent response to the first treatment. Sixty-eight of 71 had no evidence of disease after an average follow-up of 7·2 years. In patients with detectable Stim-Tg1 (98/169; 58%), Stim-Tg2 became negative in 40. The negative predictive value (NPV) of Stim-Tg1 was 0·96. The optimal Stim-Tg1 cut-off level for identifying persistence was 3·65 ng/ml. Recurrence was detected in 14 patients. Neck US was useful for identifying local recurrence (13/14; 92·85%).

CONCLUSIONS

Stim-Tg1 is a reliable marker with a high NPV. A second stimulation test should be avoided in patients with negative Stim-Tg1. In patients with biochemical persistence, Stim-Tg2 is useful for confirming/ruling out final status. Neck US plays a valuable role in the early diagnosis of recurrence.

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 ≥1 ng/mL, negative Tg antibodies, and no structural evidence of disease. None received empiric radioiodine therapy. Follow-up (median: 9.6 years) 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 3 years. In 17 (20 %), imaging findings were consistently negative, but the final stimulated Tg levels was still >1 ng/mL (median 2.07 ng/mL, range 1.02-4.7). The other 68 (80 %) appeared disease-free (persistently negative imaging findings with stimulated Tg levels ≤1 ng/mL). Mean intervals between first and final stimulated Tg assays were similar (5.2 and 4.8 years) in subgroups with versus without Tg normalization. Reclassification as disease-free was significantly more common when initial stimulated Tg levels were indeterminate (<10 ng/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.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Low Recurrence Rates in a Cohort of Differentiated Thyroid Carcinoma Patients: A Referral Center Experience

BACKGROUND

Trends in the epidemiological profiles of differentiated thyroid cancer (DTC) have shifted the disease spectrum. This study aimed to evaluate the recurrence rates and identify factors related to persistent disease in a contemporary cohort of patients with DTC.

METHODS

A cohort of DTC patients submitted to total thyroidectomy followed in a referral center were included in the study. "Disease free" was defined as no clinical, imaging, or biochemical evidence of tumors. "Recurrence" was defined as evidence of disease in a patient who had been previously classified as disease free.

RESULTS

A total of 786 patients were included. The mean age at diagnosis was 45.8±15.1 years, 81.6% were female, and papillary thyroid cancer accounted for 86.6% of cases. The median tumor size was 2.0 cm, 28.5% had lymph node involvement, and 6.1% had distant metastases. Disease status after the initial therapy was available for 548 patients: 357 (65.1%) were disease free, and 191 (34.9%) had persistent disease (90 biochemical and 101 structural disease). In multivariate model analyses, the variables male sex, lateral lymph nodal involvement, distant metastasis, and 2009 ATA high-risk classification were independent prognostic factors for persist disease. After a four-year follow-up (two to eight years), 97.2% of the patients who had been classified as disease free remained in disease remission status. Of the 10 (2.8%) patients with recurrent disease, eight presented biochemical and two cervical structural disease.

CONCLUSIONS

The majority of the DTC patients who were considered to be disease free after the initial treatment remained with this status at long-term follow-up. These data suggest that less intensive follow-up may apply for these patients.

Update on differentiated thyroid cancer staging

In this review, we demonstrate how initial estimates of the risk of disease-specific mortality and recurrent/persistent disease should be used to guide initial treatment recommendations and early management decisions and to set appropriate patient expectations with regard to likely outcomes after initial therapy of thyroid cancer. The use of ongoing risk stratification to modify these initial risk estimates is also discussed. Novel response to therapy definitions are proposed that can be used for ongoing risk stratification in thyroid cancer patients treated with lobectomy or total thyroidectomy without radioactive iodine remnant ablation.

Outcomes of patients with differentiated thyroid cancer risk-stratified according to the American thyroid association and Latin American thyroid society risk of recurrence classification systems

OBJECTIVES

The aims of this study were to validate the proposed Latin American Thyroid Society (LATS) risk of recurrence stratification system and to compare the findings with those of the American Thyroid Association (ATA) risk of recurrence stratification system.

SUBJECTS AND METHODS

This study is a retrospective review of papillary thyroid cancer patients treated with total thyroidectomy and radioactive iodine at a single experienced thyroid cancer center and followed according to the LATS management guidelines. Each patient was risk-stratified using both the LATS and ATA staging systems. The primary endpoints were (i) the best response to initial therapy defined as either remission (stimulated thyroglobulin [Tg] <1 ng/mL, negative ultrasonography) or persistent disease (biochemical and/or structural), and (ii) clinical status at final follow-up defined as no evidence of disease (suppressed Tg <1 ng/mL, negative ultrasonography), biochemical persistent disease (suppressed Tg >1 ng/mL in the absence of structural disease), structural persistent disease (locoregional or distant metastases), or recurrence (biochemical or structural disease identified after a period of no evidence of disease).

RESULTS

One hundred seventy-one papillary thyroid cancer patients were included (mean age 45 ± 16 years, followed for a median of 4 years after initial treatment). Both the ATA and LATS risk stratification systems provided clinically meaningful graded estimates with regard to (i) the likelihood of achieving remission in response to initial therapy, (ii) the likelihood of having persistent structural disease in response to initial therapy and at final follow-up, (iii) the likely locations of the persistent structural disease (locoregional vs. distant metastases), (iv) the likelihood of recurrence, and (v) the likelihood of being no evidence of disease at final follow-up. The likelihood of having persistent biochemical evidence of disease was not significantly different across the staging categories.

CONCLUSIONS

Both the ATA and LATS risk of recurrence systems effectively risk-stratify patients with regard to multiple important clinical outcomes. When used in conjunction with a staging system that predicts disease-specific mortality, either of these systems can be used to guide risk-adapted individualized initial management recommendations.

Long-term clinical outcome of differentiated thyroid cancer patients with undetectable stimulated thyroglobulin level one year after initial treatment

BACKGROUND

Measurement of the serum thyroglobulin (Tg) level with TSH stimulation (sTg) is the cornerstone of monitoring for the recurrence or persistence of differentiated thyroid cancer (DTC) in patients who have undergone surgery and remnant ablation. However, there have been several reports that an undetectable sTg could not predict the absence of future recurrence. The aim of this study was to evaluate the long-term outcome of DTC patients who achieved biochemical remission (BR, defined as sTg<1 ng/mL) after initial treatment, and to determine the role of repeated sTg measurement in detecting a clinical recurrence.

METHODS

This is a retrospective observational cohort study in a tertiary referral hospital. There were 1010 DTC patients who achieved BR at 12 months after the initial treatment (surgery and ablation), and they were eligible for analysis. Among them, 787 patients had values of repeated sTg.

RESULTS

Thirteen out of 1010 (1.3%) patients had clinical recurrences during a median 84 months of follow-up. All of the clinical recurrences were limited to the cervical lymph nodes without clinical evidence of distant metastasis. Among 787 patients with available repeated sTg, 10 had clinical recurrences (5 out of 750 patients with repeated sTg<1 ng/mL and 5 out of 37 patients with repeated sTg ≥ 1 ng/mL). Patients with repeated sTg ≥ 1 ng/mL had a much greater chance of disease recurrence (log-rank statistics=43.7, df=1, p<0.001).

CONCLUSIONS

About 1% of DTC patients who had sTg<1 ng/mL 12 months after initial treatment had a clinical recurrence. All of clinical recurrences were loco-regional recurrences. Although repeated sTg measurement can be helpful to predict recurrence, we could not recommend it for surveillance in patients with BR due to its very low yield.

Value of repeat stimulated thyroglobulin testing in patients with differentiated thyroid carcinoma considered to be free of disease in the first year after ablation

BACKGROUND

In patients with differentiated thyroid carcinoma considered to be free of the disease after initial therapy, the appropriate timing or necessity of subsequent stimulated thyroglobulin (Tg) testing is uncertain. The objective of this study was to determine the value of a repeat stimulated Tg in patients considered to be free of disease 6-12 months after thyroid ablation, and also who continued to have serum Tg <1 ng/mL while on thyrotropin suppressive doses of thyroxine (T4) (Tg/T4), negative anti-Tg antibodies (TgAb), and a normal clinical examination 5 years after their initial therapy.

METHODS

The study participants were 203 patients who had total thyroidectomy followed by ablation with (131)I, who were considered to be free of disease 6-12 months after ablation (stimulated Tg <2 ng/mL in the absence of TgAb and negative diagnostic whole-body scanning), who had no recurrence, and who continued to have serum Tg/T4 of <1 ng/mL, negative TgAb and a normal clinical examination 5 years after initial therapy. These patients were evaluated with repeat stimulated Tg testing after 4 weeks of T4 withdrawal.

RESULTS

Repeat stimulated Tg values after 5 years were <2 ng/mL in 192 (94.6%) patients of whom 188 were <1 ng/mL. Subsequent follow-up after a mean of 102 months did not detect new cases of tumor recurrence in this subgroup. Eleven patients (5.4%) had stimulated Tg levels of >2 ng/mL. Neck ultrasonography (US) revealed metastases in three and other imaging methods detected metastases in five patients with negative US. In the other three patients, no metastases were detected initially or during follow-up. Gender, age, and tumor stage were not predictors of recurrence or elevated Tg upon repeat testing after 5 years.

CONCLUSIONS

The present results favor repeating stimulated Tg 5 years after ablation in patients who were initially considered to be free of disease and who continued to have Tg/T4 values of <1 ng/mL and negative TgAb tests. A negative predictive value of 100% was obtained for patients who continued to have low stimulated Tg values.

Usefulness of repeated recombinant human thyrotropin-stimulated thyroglobulin test in the post-surgical follow-up of very low-risk patients with differentiated thyroid carcinoma

BACKGROUND

The European Thyroid Association (ETA) and the American Thyroid Association (ATA) guidelines identify subgroups of patients affected by thyroid carcinoma in whom, due to a low risk of recurrence, radioiodine ablation is not indicated. These patients are referred to as "very low-risk" according to the ETA consensus and "low-risk" patients according to the ATA guidelines. The recommended post-surgical follow-up of these patients is based upon periodical measurements of serum thyroglobulin (Tg) on levothyroxine therapy and neck ultrasound (US).

AIM

To evaluate the usefulness of recombinant human (rh)-TSH Tg test and its repetition 2-3 yr afterwards in very low-risk patients.

MATERIALS AND METHODS

We consecutively enrolled 32 patients with undetectable anti-Tg antibodies. Basal serum Tg levels was undetectable in all patients.

RESULTS

Following rhTSH serum Tg remained undetectable in 23 (71.9%) patients (UP) and was >1.0 ng/ml in 9 (DP). US and whole body scan, revealed lymph node metastasis in 4/9 DP patients. A second rhTSH stimulation test (36.9±3.5 months later) was performed in all UP and in 5 DP patients without proven recurrences. All the UP and 4/5 formerly DP patients showed undetectable Tg stimulation.

CONCLUSIONS

Our results suggest that rhTSH Tg test may be helpful in very low-risk patients, given its ability to differentiate those who may be considered "free of disease" from those who require further investigation and treatment. Repeated rhTSH Tg tests may be indicated only in patients with detectable serum Tg at prior stimulation testing.

Approach to and treatment of differentiated thyroid carcinoma

Thyroid cancer is the most common endocrine malignancy, although representing fewer than 1% of all human tumors. Differentiated thyroid carcinoma (DTC) includes the papillary and follicular histotypes and their variants, accounting for more than 90% of all thyroid cancers. Given the changing presentation of DTC in the last years, the aim of DTC management is to ensure the most effective but least invasive treatment, and adequate follow-up for a disease that nowadays is mostly cured just with surgery and is rarely fatal. This review addresses the multiple steps of current management, based on previous assumptions.

Thyroid cancer recurrence in patients clinically free of disease with undetectable or very low serum thyroglobulin values

DESIGN

This was a retrospective clinical study.

SETTING

The study was conducted at a university-based tertiary cancer hospital.

PATIENTS

One hundred seven patients had initial thyroid cancer surgery and subsequent remnant radioiodine ablation. Patients underwent recombinant human TSH (rhTSH)-mediated diagnostic whole-body scan and rhTSH-stimulated thyroglobulin (Tg) measurement before April 2001 if they had no antithyroglobulin antibodies, were clinically free of disease, and had one or more undetectable (≤0.5 ng/ml) or low (0.6-1 ng/ml) basal Tg measurements on levothyroxine. Patients were stratified according to their rhTSH-Tg responses: group 1, Tg 0.5 ng/ml or less (68 patients); group 2, Tg from 0.6 to 2.0 ng/ml (19 patients); and group 3, Tg greater than 2 ng/ml (20 patients).

MAIN OUTCOME MEASURES

Tumor recurrence was measured.

RESULTS

In group 1, two of 62 patients (3%) with follow-up recurred. In group 2, 63% converted to group 1, whereas two of 19 (11%) converted to group 3 and then recurred. Sixteen of the initial 20 group 3 patients (80%) recurred, including recurrence rates of 69 and 100% for those with an initial rhTSH-Tg greater than 2.0 ng/ml but 5.0 ng/ml or less, and 4.6 ng/ml or greater, respectively. One group 3 patient died of distant metastases. rhTSH-Tg more accurately predicted tumor recurrence than basal Tg. An rhTSH-Tg threshold of 2.5 ng/ml or greater optimally predicted future recurrence with sensitivity, specificity, and negative and positive predictive values of 80, 97, 95, and 84%, respectively.

CONCLUSIONS

The prevalence of postablation thyroid cancer recurrence is predicted by the rhTSH-Tg response with an optimal Tg threshold of 2.5 ng/ml. Still, recurrent disease occurs in some patients with an initial rhTSH-Tg of 0.5 ng/ml or less.

Recombinant human thyroid stimulating hormone in 2008: focus on thyroid cancer management

Radioiodine (RAI) ablation following thyroidectomy is standard of care treatment for patients with intermediate or high risk differentiated thyroid cancer. Traditionally, this has been achieved by forgoing thyroid hormone replacement postoperatively, allowing endogenous thyroid stimulating hormone (TSH) levels to rise. This rise in TSH provides the stimulus for RAI uptake by the thyroid remnant, but is associated with clinical hypothyroidism and its associated morbidities. Recombinant human TSH (rhTSH, thyrotropin alfa [Thyrogen^®], Genzyme Corporation, Cambridge, MA, USA) was developed to provide TSH stimulation without withdrawal of thyroid hormone and clinical hypothyroidism. Phase III studies reported equivalent detection of recurrent or residual disease when rhTSH was used compared with thyroid hormone withdrawal (THW). These trials led to its approval as an adjunctive diagnostic tool for serum thyroglobulin (Tg) testing with or without RAI imaging in the surveillance of patients with differentiated thyroid cancer. Recently, rhTSH was given an indication for adjunctive preparation for thyroid remnant ablation after phase III studies demonstrated comparable outcomes for rhTSH preparation when compared with THW. Importantly, rhTSH stimulation has been found to be safe, well tolerated, and to result in improved quality of life. Here, we review the efficacy and tolerability studies leading to the approval for the use of rhTSH in well-differentiated thyroid cancer management.