Value of preoperative diagnostic modalities in patients with recurrent thyroid carcinoma

Ultrasound‑guided Percutaneous Radiofrequency and Microwave Ablation for Cervical Lymph Node Metastasis from Papillary Thyroid Carcinoma: A Systematic Review and Meta‑analysis of Clinical Efficacy and Safety

AIM

To evaluate the efficacy and safety of radiofrequency ablation (RFA) and microwave ablation (MWA) for treating cervical lymph node metastasis (CLNM) from papillary thyroid carcinoma (PTC).

METHODS

Medline, EMBASE, Web of Science, and Cochrane Library were searched for studies on the efficacy and safety of thermal ablations for treating CLNM from PTC until July 2024. Among 544 papers, 11 articles were reviewed involving 233 patients and 432 CLNM cases. Random- or fixed-effects models assessed pooled proportions of volume reduction rate (VRR), complete disappearance, recurrence, major and minor or other complications. Similarly, pooled estimates of changes in the largest diameter, volume, and serum thyroglobulin (Tg) were evaluated post-ablation. Subgroup analysis by treatment modality was performed. Study heterogeneity was analyzed using Q statistics and inconsistency index (I2). The quality of the studies was assessed using the MINORS scale.

RESULTS

Eleven studies with 233 patients and 432 CLNM were analyzed. The pooled VRR was 95.24% [95% Confidence Interval (CI): 91.97- 98.51%], complete disappearance was 63.1%, and recurrence was 1.6%. Changes in largest diameter, volume, and serum Tg were 8.36 mm (95%CI: 6.46-10.26mm), 216.09mm³, and 6.12ng/ml, respectively. Major complications occurred at 3.0%, while minor complications were 25.6%. Significant heterogeneity was found for diameter, volume, VRR, Tg, and minor complications. Subgroup analysis showed that MWA had a higher VRR (97.18%) than RFA (93.84%) (P < 0.001).

CONCLUSION

Both RFA and MWA were effective and safe for treating CLNM from PTC. However, RFA showed lower volume reduction than MWA with significant heterogeneity in VRR.

DATA AVAILABILITY STATEMENT

The original contributions revealed in the study are included in the article/Supplemental Material. Further inquiries can be made to the corresponding author.

Use of 18 F-2-deoxy-2-fluoro-D-glucose positron emission tomography/computed tomography for staging thyroid carcinoma in a cat

Thyroid nodules are common in older cats and are mostly benign; however, carcinomas may occur infrequently. In cats, thyroid carcinomas tend to be highly metastatic. The role of ¹⁸ F-2-deoxy-2-fluoro-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) in human thyroid carcinoma has been well established. However, guidelines have not yet been established for veterinary medicine. Metastasis assessment has typically been performed using CT in veterinary medicine; however, it is poorly sensitive in detecting regional lymph nodes or distant metastases if these lesions are not abnormally contrast-enhanced, enlarged or cause overt mass effects. This case suggested that FDG PET/CT may be used for staging feline thyroid carcinoma, and the results contributed to treatment recommendations.

Safety and efficacy of thermal ablation for cervical metastatic lymph nodes in papillary thyroid carcinoma: A systematic review and meta-analysis

BACKGROUND

To evaluate the safety and efficacy of radiofrequency ablation (RFA), microwave ablation (MWA), and laser ablation (LA) for the treatment of cervical metastatic lymph nodes (CMLNs) of papillary thyroid carcinoma (PTC).

METHODS

The Pubmed, EMBASE, Web of Science, and Cochrane Library databases were searched for studies on the safety and efficacy of thermal ablations (RFA, MWA, and LA) for the treatment of CMLNs of PTC until March 30, 2022. A review of 334 potential papers identified 17 eligible papers including 312 patients. Fixed-effects model or random-effects model was used to evaluate the pooled proportions of volume reduction rate (VRR), complete disappearance, and recurrence, and pooled estimates of changes in the largest diameter, volume, and serum Tg after ablation. The pooled proportions of overall and major complications were calculated. Subgroup analysis based on treatment modalities. The heterogeneity among studies was analyzed by using Q statistics and inconsistency index I² . MINORS scale was used to evaluate the quality of the studies.

RESULTS

17 eligible studies were finally identified, including 312 patients and 559 CMLNs. The pooled proportions of VRR, complete disappearance and recurrence of CMLNs were 91.28% [95% confidence interval (CI): 86.60-95.97%], 67.9% [95% CI: 53.1-81.1%] and 7.8% [95%CI: 3.0-14.1%], respectively. The pooled estimates of changes in the largest diameter, volume and serum Tg were 8.12 mm [95%CI: 6.78-9.46 mm], 338.75 mm³ [95%CI: 206.85 -470.65 mm³] and 5.96 ng/ml [95%CI: 3.68-8.24 ng/ml], respectively. The pooled proportions of overall and major complications were 2.9% [95%CI: 0.3-7.1%] and 0.3% [95%CI: 0-1.9%], respectively. Significant between-study heterogeneity was observed for complete disappearance (P<0.01, I² =88.6%), VRR (P<0.001, I² =99.9%), recurrence (P=0.02, I² =47.76%), overall complications (P<0.02, I² =44.8%), and changes in the largest diameter (P < 0.001, I² =82.6%), volume (P<0.001, I² =97.0%), and serum Tg (P < 0.001, I² =93.7%). Subgroup analysis showed heterogeneity of the VRR among the treatment modality (I² range: 84.4-100%). The VRR of MWA was the highest (97.97%), followed by RFA (95.57%) and LA (84.46%) (P < 0.001).

CONCLUSION

All thermal ablations were safe and effective for the treatment of CMLNs of PTC. However, each treatment had significant heterogeneity in VRR. Compared with RFA and MWA, LA was less effective in reducing the volume of CMLNs of PTC.

Simultaneous measurements of single gamma ray of 131I and annihilation radiation of 18F with Compton PET hybrid camera

In internal 131I therapy for thyroid cancer, a decision to continue treatment is made by comparing 131I scintigraphy and [18F]FDG-PET. However, with current SPECT and PET systems, simultaneous imaging of diagnostic PET nuclides and therapeutic 131I nuclides has not been achieved so far. Therefore, we demonstrated that the recently developed Compton PET hybrid camera with Ce:Gd3(Al,Ga)5O12 (GAGG)- Silicon Photomultiplier(SiPM) scintillation detectors can be used to simultaneously image 131I Compton image and 18F PET image.

Clinical Indications for Treatment with Multi-Kinase Inhibitors in Patients with Radioiodine-Refractory Differentiated Thyroid Cancer

Differentiated thyroid cancer is usually a slow-growing disease, even if the patients develop distant metastasis. For recurrent or metastatic disease, radioactive iodine therapy is a standard treatment. However, the disease gradually progresses in some of the patients and can ultimately develop into life-threatening conditions. For patients with progressive radioactive iodine-refractory differentiated thyroid cancer (RR-DTC), multi-kinase inhibitors (MKIs) including sorafenib and lenvatinib prolonged progression-free survival compared with placebo in pivotal randomized phase 3 trials, although the benefit in overall survival has not been clearly confirmed, possibly because the patients who received placebo were permitted to cross-over to lenvatinib upon disease progression. Moreover, the adverse events related to MKIs were not negligible. Therefore, the optimal timing of MKI initiation has long been controversial, and physicians should consider various patient and disease factors. Herein, we comprehensively review the clinical factors that can be helpful in determining the initiation of MKIs for patients with RR-DTC.

Endoscopic Lateral Neck Dissection (IIA, IIB, III, and IV) Using a Breast Approach: Outcomes From a Series of the First 24 Cases

INTRODUCTION

In order to avoid large neck scar caused by conventional lateral neck dissection. We have explored and introduced endoscopic lateral neck dissection (IIA, IIB, III, and IV) using a breast approach. Now, we summarized and shared the outcomes of the first 24 cases.

MATERIALS AND METHODS

All the patients were treated in our institute from January 2017 to May 2018, and followed-up for more than 1 year. The details of patients and this technique have been summarized and analyzed retrospectively.

RESULTS

A series of first 24 cases were successfully managed with this technique, and no cases were converted to an open approach. Among these 24 patients, levels III + IV dissection had been performed in 6 patients and levels II+III+IV dissection had been performed in 18 patients. The mean age, body mass index, and sex were 39.3±10.5 years old, 24.1±3.5, and 2 male/22 female, respectively. The average operative time of total operation and lateral neck dissection was 238.8±37.2 minutes and 128.8±21.1 minutes, respectively. The mean dissected lateral lymph nodes were 5.9±2.2 (level II) in 18 cases and 15.9±3.9 (levels III+IV) in 24 cases. In addition, with no severe complications to date, such as asphyxia, main nerves injury (cervical plexus, vagus nerve, etc.), and permanent hypoparathyroidism, nor permanent recurrent laryngeal nerve injury, and so on. However, unexpectedly, had some mild and common complications like transient hypocalcemia in 4 cases (16.67%), transient horse 1 case (4.2%), controllable lymphatic leakage in 2 cases (8.3%), and controllable jugular vein injury in 2 cases (8.3%). One year after the operation, 1 case found lung metastasis but no local recurrence. In other 23 patients, no recurrence/metastasis and the average of serum thyroglobulin is 3.2±3.8 ng/mL.

CONCLUSIONS

This technique can yield adequate oncological dissection for selected patients. Endoscopic thyroidectomy along with lateral neck dissection using a breast approach may provide an option for selected patients who favor avoiding a visible neck incision.

125I radioactive seed localization (RSL) in surgery of cervical metastasis of thyroid cancer

INTRODUCTION

The aim of this work is the evaluation of usefulness of radioactive seed localization (RSL) for the detection of cervical recurrence of thyroid cancer in order to improve the surgical outcome.

MATERIAL AND METHOD

Ten patients with thyroid cancer and lymph node involvement (4 naive and 6 with cervical recurrence) evidenced by ultrasound, cytology/Tg-FNAB (reoperated group) were selected for this procedure. A ¹²⁵I seed was placed in the metastatic lesion using a needle guided by ultrasound. During surgery, a handheld gamma probe/portable gammacamera were used for lesion localization and excision. After removing the target tissue, it was verified that the seed was included in the excised tissue. Surgical intervention duration, lesion location, seed activity, thyroglobulin level, effective radiation dose, complications and the degree of surgical resection were analyzed.

RESULTS

All the marked nodes were positive in histology. The mean duration of the ultrasound procedure was 11.4±3.4minutes. Seed was kept inside the patient, in average, during 4days (1-7) and the average surgical time was 44.7±29.1minutes. We found 21 metastatic specimens with an average diameter 13.9±6.3mm. The mean activity of the implanted seed was 71.27±21.6MBq (42.8-105) In the reoperated group, thyroglobulin level was 2.08±1.56ng/dl and decreased after surgery to 0.13±0.12ng/dl, P<.01. Only one case of transient hypoparathyroidism was found in the total group.

CONCLUSIONS

The introduction of RSL in our unit has shown benefits for the patient and medical team, being a safe and effective procedure that also improves surgical programming.

FDG PET Hybrid Imaging

Molecular imaging with positron emission tomography (PET) using tumour-seeking radiopharmaceuticals has gained wide acceptance in oncology with many clinical applications. The hybrid imaging modality PET/CT (computed tomography) allows assessing molecular as well as morphologic information at the same time. Therefore, PET/CT represents an efficient tool for whole-body staging and re-staging within one imaging modality. In oncology, the glucose analogue 18-F-fluorodeoxyglucose (FDG) is the most widely used PET/CT radiopharmaceutical in clinical routine. FDG PET and FDG PET/CT have been used for staging and re-staging of tumour patients in numerous studies. This chapter will discuss the use and the main indications of FDG PET/CT in oncology with special emphasis on lung cancer, lymphoma, head and neck cancer, melanoma and breast cancer (among other tumour entities). A review of the current literature is given with respect to primary diagnosis, staging and diagnosis of recurrent disease. Besides its integral role in diagnosis, staging and re-staging of disease in oncology, there is increasing evidence that FDG PET/CT can be used for therapy response assessment (possibly influencing therapeutic management and treatment planning) by evaluating tumour control, which will also be discussed in this chapter.

The Transareola Endoscopic Approach Yields Adequate Oncological Dissection as Open Approach in the Treatment of Papillary Thyroid Carcinoma

OBJECTIVE

This study aimed to evaluate and discuss whether the transareola endoscopic surgery has similar outcome outcomes to open surgery in the treatment of papillary thyroid carcinoma (PTC).

METHOD

A total of 102 patients with PTC were enrolled in this study. Among them, 53 patients were treated by transareola endoscopic surgery (endoscopic group) and 49 patients were treated by open surgery (open group). Some specific factors, including thyroglobulin (Tg), radioactive iodine uptake (RAIU), postoperative nuclide imaging in thyroid area, postoperative nuclide imaging of lymph nodes suspicious for metastasis (PNILNSM), etc. were analyzed and compared between the 2 groups.

RESULTS

There were no significant differences between the 2 groups regarding body mass index (22.9±3.4 vs. 24.0±3.3, P=0.103), operation time (173.3±43.2 vs. 158.8±47.9 min, P=0.110), intraoperative blood loss (41.8±19.4 vs. 35.8±31.0 mL, P=0.251, P=0.251), tumor diameter (19.0±6.8 vs. 20.2±7.2 mm, P=0.400), and overall complications (11.3% vs. 10.2%, P=0.868). No significant difference was found in the specific factors between the 2 groups concerning RAIU-2h/24h (2.44±1.34 vs. 2.58±1.65%/2.83±3.75 vs. 2.35±3.44%, P=0.646/ P=0.506), number of dissected lymph nodes (4.4±1.4 vs. 4.6±1.5, P=0.595), Tg before radioiodine therapy (4.46±5.50 vs. 5.60±8.36; P=0.495), Tg after radioiodine therapy (1.03±1.93 vs. 1.11±1.61, P=0.812, P=0.812), postoperative nuclide imaging in thyroid area (1.76±1.50 vs. 2.19±1.85 cm, P=0.195), PNILNSM before radioiodine (none: 79.2% vs. 83.7%, P=0.566; central: 17.0% vs. 12.2%, P=0.653; lateral: 1.9% vs. 4.1%, P=0.450; central+lateral: 1.9% vs. 0%, P=1.000), and PNILNSM after radioiodine (none: 94.3% vs. 95.9%, P=0.111; central: 3.8% vs. 2.0%, P=1.000; lateral: 0 vs. 2.0%, P=0.480; central+lateral: 1.9% vs. 0%, P=1.000).

CONCLUSIONS

Transareola endoscopic total thyroidectomy and central lymph nodes dissection are safe and effective. According to the evaluated postoperative specific factors, this technique achieves similar outcomes to open surgery in selected patients with PTC.

An Unusual Case of Metastatic Follicular Thyroid Cancer 40 Years after Initial Diagnosis

Thyroid cancer recurrence can occur decades after initial diagnosis despite excellent response to therapy. Thyroid cancer recurrence is evaluated using serum thyroglobulin (Tg) and imaging studies including I-131 WBS and neck ultrasound. Limitations in Tg measurement and WBS may result in failure to detect recurrence. We report the case of a 63-year-old man who was noted to have rhonchi during a routine visit. He had a past history of follicular thyroid cancer that was diagnosed 40 years ago and treated with total thyroidectomy and radioactive iodine. He had excellent response to therapy with undetectable Tg levels, normal neck ultrasounds, and multiple negative whole body scans (WBS) due to which he was discharged from endocrinology clinic after 37 years of follow-up. Chest X-ray revealed a left lung mass with biopsy positive for thyroid cancer. Tg remained undetectable with negative anti-Tg antibody. Left pneumonectomy was done which revealed a mix of 70% differentiated thyroid cancer and 30% poorly differentiated/anaplastic thyroid cancer. He received two cycles of Doxorubicin and Paclitaxel. At 4 months follow-up after surgery, he had 3 subcentimeter nodules in his right lung. This case highlights that physical exam remains an essential tool to evaluate for recurrence. Since the lungs are the most common site of metastasis in follicular thyroid cancer, a chest X-ray may help detect metastasis that is missed on other modalities.

Treatment of differentiated thyroid cancer: can endoscopic thyroidectomy via a chest-breast approach achieve similar therapeutic effects as open surgery?

BACKGROUND

An analysis of some special factors was performed to further evaluate and discuss whether endoscopic surgery and traditional open surgery have similar therapeutic outcomes for differentiated thyroid cancer (DTC).

METHODS

A retrospective study was performed on 76 patients undergoing surgery to treat DTC. Forty patients were treated by endoscopic thyroidectomy via the chest-breast approach (endoscopic group) and thirty-six patients were treated by open surgery (open group). Serum thyroglobulin (sTg), radioactive iodine uptake (RAIU), radioactive technetium uptake (RATU), radionuclide imaging of the thyroid residual area (RITRA), radionuclide imaging of suspicious lymph nodes metastasis (RISLNM), and other general indexes were analyzed and compared between the two groups.

RESULTS

All surgeries were successfully completed in both groups. There were no significant differences between the two groups regarding gender (P = 0.120), postoperative hospital stay (P = 0.766), operation time (P = 0.065), intra-operative blood loss (P = 0.064), tumor diameter (P = 0.059), and overall complications (P = 0.828). Among these complications, there was no significant difference between the two approaches in transient hypoparathryoidism (P = 0.771), transient recurrent laryngeal injury (P = 0.474) and serious neck skin traction sensation (2.5 vs. 0%, P = 1.000). Age and body mass index were lower in the endoscopic group than the open group (P < 0.05). No significant difference was found in special factors between two groups concerning surgical range (P = 0.872), RAIU-2 h/24 h (P = 0.660/P = 0.955), RATU (P = 0.116), number of dissected lymph nodes (P = 0.157), sTg before radioiodine therapy (P = 0.188), sTg after radioiodine therapy (P = 0.159), RITRA at different time points (99mTc 15 min: P = 0.144; 131I 24 h: P = 0.243; 131I 72 h: P = 0.624) and RISLNM (none: P = 0.805; central: P = 0.744; lateral: P = 1.000; central + lateral: P = 0.958).

CONCLUSION

Endoscopic total thyroidectomy and central lymph nodes dissection via a chest-breast approach are safe and effective. Through the detection of the postoperative special factors, a well-trained surgeon can achieve similar therapeutic results for selected patients with DTC, compared with open surgery.

Optimierung der Schilddrüsen- Feinnadelpunktion

Objective: Optimization of a specially developed automatic microaspirator for fine-needle aspiration of suspicious thyroid nodules. Patients, method: In a preliminary test biopsy effectiveness was evaluated in 20 native resected thyroid glands in vitro with both a Cameco® gun and a specially designed microaspirator respectively. In addition in both techniques two different needles (21-G and 27-G) were used to evaluate the influence of these two cannula. Subsequently, 103 thyroid nodules were biopsied in vivo and compared the results with a preliminary series of the same physician. In the workup and evaluation of the cytology the ThinPrep® technology was used. Results: In vitro the automatic microaspirator was superior to Cameco gun in both when using the 21-Gauge and the 27-Gauge needle. In terms of needle sizes a statistically significant difference at the 95% confidence level was evident for both comparisons in favor of 21-gauge needle. In vivo, 91% of punctures with the microaspirator were usable, while in the pre-series only 84% were usable (p > 0.05). Conclusion: The automatic microaspirator is superior to the manual aspiration. Moreover, under sonographic control it is more convenient, to biopsy even very small nodules and lesiosn (down to 4 mm in diameter)

A Case of Thyroid Papillary Carcinoma: Remarkable Decrease in Multiple Lung Metastases within 40 Years after a Single Administration of Radioiodine without Thyroidectomy and with Later Anaplastic Transformation

Differentiated thyroid carcinoma is an uncommon malignancy of childhood and adolescence that is unique because it has an overall favorable prognosis despite its relatively high rate of nodal and distant metastases. Total thyroidectomy and positive ¹³¹I therapy are recommended for cases with pulmonary metastases. In contrast, anaplastic thyroid cancer is one of the most aggressive malignancies that have an unfavorable and miserable prognosis. We report a case with an impressively long history. The patient had multiple pulmonary metastases that had been diagnosed by ¹³¹I administration when he was 14 years old, about 45 years before he underwent thyroidectomy. He had been kept unaware of his disease by his family and received no treatment for most of his life. Pulmonary nodules were noted at several medical checkups and showed a remarkable decrease in size during the untreated 44-year period after the ¹³¹I administration. At age 58, his thyroid cancer was first detected and total thyroidectomy was performed, with subsequent radioiodine therapy for pulmonary metastases. Unfortunately, anaplastic carcinoma developed and he died of disseminated tumors later.

Use of thyroglobulin as a tumour marker

It is worthwhile to measure serum thyroglobulin (TG) level in thyroid cancer before subjecting patients to surgery for two reasons. Firstly, if the level is high, it may give a clue to the local and metastatic tumour burden at presentation; secondly, if the level is normal, it identifies the patients who are unlikely to show rising TG levels in the presence of thyroid cancer. Those who have high serum TG before surgery will show up recurrence as rising serum TG during the postoperative period. Those who do not have high serum TG before surgery will not show up rising serum TG in the presence of recurrent disease. In the latter situation, normal TG level gives only a false reassurance regarding recurrence of disease. Nevertheless, rising serum TG during the postoperative period must be interpreted cautiously because this could be due to the enlargement of non-cancerous residual thyroid tissue inadvertently left behind during surgery.

Diagnostic Whole-Body Scan May Not Be Necessary for Intermediate-Risk Patients with Differentiated Thyroid Cancer after Low-Dose (30 mCi) Radioactive Iodide Ablation

BACKGROUND

A diagnostic whole-body scan (WBS) is recommended 6 to 12 months after total thyroidectomy and radioactive iodide ablation in intermediate- or high-risk patients with differentiated thyroid cancer (DTC). The aim of this study was to evaluate the necessity of a diagnostic WBS after radioactive iodide ablation in intermediate-risk patients with DTC.

METHODS

A total of 438 subjects were included in the study: 183 low-risk subjects and 255 intermediate-risk subjects according to the American Thyroid Association guideline. All subjects diagnosed with DTC received 1,100 MBq (30 mCi) activity of radioiodine (I-131) following total thyroidectomy. On follow-up, all subjects underwent a diagnostic I-131 WBS after thyroid hormone withdrawal.

RESULTS

After initial radioactive iodide ablation, 95.1% of low-risk patients and 91.4% of intermediate-risk patients showed no uptake on diagnostic WBS (P=0.135). Intermediate-risk patients with stimulated thyroglobulin (Tg) levels higher than 2.0 ng/mL showed a greater rate of radioactive iodine uptake on diagnostic WBS. Four intermediate-risk patients showed recurrence during the 16 to 80 months follow-up period. Three of the four patients with recurrence showed no uptake on diagnostic WBS and had a stimulated Tg level less than 2.0 ng/mL.

CONCLUSION

A diagnostic I-131 WBS after radioactive iodide ablation in intermediate-risk patients with DTC may not be necessary. A large prospective study is necessary to determine the necessity of diagnostic WBS in intermediate-risk patients with DTC.

Is Every Patient Followed up as a Papillary Thyroid Cancer Patient Really That?

We report the case of a 64-year-old man followed up for two years as suffering from differentiated thyroid cancer (DTC). In the patient's follow up, despite thyroglobulin level and I-131 whole body scan results being normal, metastases were identified at the 4th thoracic vertebra corpus by MR. Histopathological findings were carcinoma metastases. F-18 FDG PET/CT showed increased metabolic activity in the right renal mass, bilaterally in the surrenal gland, multiple lymph nodes in the thoracic and abdominal para-aortic region and in multiple vertebral and pelvic bones. An excisional biopsy of the right renal mass was reported as renal cell carcinoma. Immunohistochemical staining performed retrospectively to the first thyroid preparation showed renal cell carcinoma metastases. Consequently, any patient who presents with a thyroid nodule can also be considered as possibly suffering from metastatic disease. F-18 FDG PET/CT can provide valuable information in finding the primary focus and metastases.

CONFLICT OF INTEREST

None declared.

Effectiveness of [(124)I]-PET/CT and [(18)F]-FDG-PET/CT for localizing recurrence in patients with differentiated thyroid carcinoma

Although the prognosis of patients with differentiated thyroid carcinoma (DTC) is generally encouraging, a diagnostic dilemma is posed when an increasing level of serum thyroglobulin (Tg) is noted, without detection of a recurrent tumor using conventional imaging tools such as the iodine-131 whole-body scanning (the [(131)I] scan) or neck ultrasonography (US). The objective of the present study was to evaluate the diagnostic value of [(124)I]-PET/CT and [(18)F]-FDG-PET/CT in terms of accurate detection of both iodine- and non-iodine-avid recurrence, compared with that of conventional imaging such as the [(131)I] scan or neck ultrasonography (US). Between July 2009 and June 2010, we prospectively studied 19 DTC patients with elevated thyroglobulin levels but who do not show pathological lesions when conventional imaging modalities are used. All involved patients had undergone total thyroidectomy and radioiodine (RI) treatment, and who had been followed-up for a mean of 13 months (range, 6-21 months) after the last RI session. Combined [(18)F]-FDG-PET/CT and [(124)I]-PET/CT data were evaluated for detecting recurrent DTC lesions in study patients and compared with those of other radiological and/or cytological investigations. Nine of 19 patients (47.4%) showed pathological [(18)F]-FDG (5/19, 26.3%) or [(124)I]-PET (4/19, 21.1%) uptake, and were classed as true-positives. Among such patients, disease management was modified in six (66.7%) and disease was restaged in seven (77.8%). In particular, the use of the described imaging combination optimized planning of surgical resection to deal with locoregional recurrence in 21.1% (4/19) of patients, who were shown to be disease-free during follow-up after surgery. Our results indicate that combination of [(18)F]-FDG-PET/CT and [(124)I]-PET/CT affords a valuable diagnostic method that can be used to make therapeutic decisions in patients with DTC who are tumor-free on conventional imaging studies but who have high Tg levels.

Differentiated thyroid cancer: management of patients with radioiodine nonresponsive disease

Differentiated thyroid carcinoma (papillary and follicular) has a favorable prognosis with an 85% 10-year survival. The patients that recur often require surgery and further radioactive iodine to render them disease-free. Five percent of thyroid cancer patients, however, will eventually succumb to their disease. Metastatic thyroid cancer is treated with radioactive iodine if the metastases are radioiodine avid. Cytotoxic chemotherapies for advanced or metastatic noniodine avid thyroid cancers show no prolonged responses and in general have fallen out of favor. Novel targeted therapies have recently been discovered that have given rise to clinical trials for thyroid cancer. Newer aberrations in molecular pathways and oncogenic mutations in thyroid cancer together with the role of angiogenesis in tumor growth have been central to these discoveries. This paper will focus on the management and treatment of metastatic differentiated thyroid cancers that do not take up radioactive iodine.

Predictive factors related to the recurrence at US-guided fine needle aspiration in postoperative patients with differentiated thyroid cancer

OBJECTIVES

The recent American Thyroid Association management guidelines suggest cervical ultrasonography (US) surveillance in patients with differentiated thyroid cancer (DTC). This study was conducted to identify predictive factors that can determine whether subsequent fine needle aspiration guided by ultrasound (US-FNA) is indicated in patients with lesions detected by US after surgery for DTC.

DESIGN

Retrospective analysis at a university-based tertiary hospital.

PATIENTS AND MEASUREMENTS

We reviewed 207 cases of postoperative US-FNA in 180 patients diagnosed with DTC. We examined the relationship between US-FNA histology and clinical factors, imaging abnormalities found by US and with other modalities and pathological staging.

RESULTS

US-FNA recurrence was positive in 56 (27%) cases and negative in 151 (73%) cases. The mean lesion size for FNA was 0·83 cm (range 0·2-2·9 cm). Univariate analysis indicated that tumour recurrence on US-FNA is associated with elevated stimulated thyroglobulin (sTg) levels, with the initial size of the primary tumour, with abnormal US findings, including the ipsilateral site, level III or IV location and extrathyroidal extension, and with other imaging abnormalities. However, multivariate analysis revealed an independent association between recurrence on FNA and suspicious US findings (OR 9·410; 95% CI 3·322-26·654; P<0·001) and elevated serum sTg (OR 5·001; 95% CI 1·067-23·485; P =0·041). Findings on US that were discriminating for recurrent nodules at the thyroidectomy site were abnormalities that were not oval shape or which had an irregular margin. Calcifications or cystic change showed a low sensitivity of 14%.

CONCLUSIONS

US-FNA for diagnosis of recurrence after surgery for DTC may be limited to patients with elevated sTg or with lesions that have specific suspicious US findings.

Diagnostic accuracy of ultrasound and 18-F-FDG PET or PET/CT for patients with suspected recurrent papillary thyroid carcinoma

The purpose of this study was to evaluate the diagnostic accuracies of ultrasound (US) and 18-F-FDG positron emission tomography (PET) or PET/computed tomography (CT) for detecting recurrent papillary thyroid carcinoma (PTC) after total thyroidectomy. Our study enrolled 76 postoperative patients who underwent both neck US and PET because of the suspicion of recurrence. The results of US and PET were correlated with the histopathology, the radioactive iodine whole body scan (WBS) or the clinical follow-up results. Among them, 53 patients had recurrent disease (local recurrence, 42; distant metastasis, 3; elevated Tg level, 8) and 23 showed no evidence of disease. From the analysis, US showed higher diagnostic accuracy, sensitivity and specificity compared with those of PET (71.1%, 71.7% and 69.6% vs. 55.3%, 56.6%, and 52.2%). PET added diagnostic information in a limited number of patients with negative results on neck US (3 with neck recurrence and 2 with distant metastasis).

Early recurrence of papillary and follicular thyroid carcinoma predicts a worse outcome

BACKGROUND

The occurrence of recurrent papillary and follicular thyroid carcinomas is not unusual. Numerous studies have reported the association between risk factors of initial surgery and recurrence of papillary and follicular thyroid carcinomas. However, we do not have sufficient data to analyze the time of postoperative recurrence associated with therapeutic results and cancer mortality. We hypothesized that an early recurrence of papillary and follicular thyroid cancers implies a rapid growth of cancer resulting in high mortality rate.

METHODS

We conducted a retrospective study in a medical center in northern Taiwan. The investigation included 2148 cases of papillary and follicular thyroid carcinoma, including 325 recurrent cases during the period between 1977 and 2006. The studied cases were categorized into early or late recurrence groups. Cases with an early recurrence were defined as those in which recurrence occurred in the first year following thyroid surgery.

RESULTS

Tumor size, radioactive iodide treatment, multifocality, and tumor-node metastasis stage were independent predictors of recurrence. After a mean follow-up of 8.7 +/- 0.1 years, death due to thyroid cancer was observed to occur in 105 (32.3%) recurrent cases. Among the 325 recurrent cases, early recurrence was detected in 185 cases, and late recurrence was detected in 140 cases. Early recurrence was mostly observed in older male patients; a high mortality rate was associated with these cases. Distant metastases were observed in about 80% of the cases in the early recurrence group, whereas localized metastases in the neck region were observed in more than half the cases in the late recurrence group. The percentage of patients with a non-disease-free status and distant metastases in the early recurrence group was higher than that in the late recurrence group. The 10-year disease-specific survival rates were 52.5% and 85.1% for the early and late recurrence groups, respectively.

CONCLUSIONS

Early recurrent papillary and follicular thyroid carcinomas are associated with high mortalities. Tumor size and multifocality deserve consideration as indicators of recurrence. Therefore, patients whose primary follicular or papillary thyroid carcinoma has features associated with early recurrence should probably receive more aggressive initial treatment.

The role of single-photon emission computed tomography/computed tomography for precise localization of metastases in patients with differentiated thyroid cancer

PURPOSE

It is very important in the management of patients with differentiated thyroid cancer (DTC) to precisely localize the foci of I-131 uptake, but it is difficult because of a lack of anatomic landmarks. The purpose of this study was to investigate the added value of I-131 single-photon emission computed tomography (SPECT)/computed tomography (CT) fusion imaging using a hybrid system in patients with DTC.

METHODS

Ninety-four patients with DTC underwent I-131 SPECT/CT using a hybrid tomography consisting of a dual-head variable-angle gamma camera and a low-dose X-ray tube. Results were compared with I-131 whole-body scan (WBS). SPECT/CT was performed 5-7 days after administration of a therapeutic dose of I-131. Fusion images were constructed by combining the digital CT and SPECT images on a computer workstation.

RESULTS

Compared with I-131 WBS, SPECT/CT imaging had improved the precise localization in 21% (20/94) of patients. In addition, SPECT/CT provided additional clinical data in 12 of the patients examined (12/94) and also caused physicians to reconsider the (131)I therapeutic approach in 22 patients.

CONCLUSION

The results of the current study indicate that the addition of I-131 SPECT/CT to WBS can improve the localization of metastases in patients with DTC. It may also detect metastases missed by WBS and adjust the therapy plan.

Assessment of the incremental value of recombinant thyrotropin stimulation before 2-[18F]-Fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography imaging to localize residual differentiated thyroid cancer

PURPOSE

The purpose of the study was to assess prospectively the impact of recombinant human TSH (rhTSH) administration on positron emission tomography (PET)/computed tomography (CT) imaging in differentiated thyroid cancer patients who, after primary treatment, had a suppressed or stimulated serum thyroglobulin greater than 10 ng/ml and no radioactive iodine uptake consistent with thyroid cancer on a whole body scan.

PATIENTS AND METHODS

PET/CT was performed before (basal PET) and 24-48 h after rhTSH administration (rhTSH-PET) in 63 patients (52 papillary and 11 follicular thyroid cancers). Images were blindly analyzed by two readers. The proposed treatment plan was prospectively assessed before basal PET, after basal PET, and again after rhTSH-PET.

RESULTS

A total of 108 lesions were detected in 48 organs in 30 patients. rhTSH-PET was significantly more sensitive than basal PET for the detection of lesions (95 vs. 81%; P = 0.001) and tended to be more sensitive for the detection of involved organs (94 vs. 79%; P = 0.054). However, basal PET and rhTSH-PET did not have significantly different sensitivity for detecting patients with any lesions (49 vs. 54%; P = 0.42). Changes in treatment management plan occurred in 19% of the patients after basal PET. Lesions found only by rhTSH-PET contributed to an altered therapeutic plan in eight patients, among whom only four were true-positive on pathology (6%).

CONCLUSION

The use of rhTSH for 2-[18F]-fluoro-2-deoxy-D-glucose-PET/CT significantly increased the number of lesions detected, but the numbers of patients in whom any lesion was detected were no different between basal and rhTSH-stimulated PET/CT scans. Treatment changes due to true positive lesions occurred in 6% of cases.

[Usefulness of ultrasound in the diagnosis and management of well-differentiated thyroid carcinoma]

Thyroid nodules are found in the vast majority of the population, but only 5 to 10% are malignant. Ultrasonography of the thyroid, by virtue of being a straightforward, non-invasive method presenting strong correlation with macroscopic aspects of the thyroid gland, is being increasingly used to identify nodules that present a higher risk of malignancy. The presence of certain ultrasonographic characteristics such as hypoechogenicity, microcalcifications, irregular contours and central vascularization on Doppler, increase the risk of the lesion being malignant. Conversely, nodules presenting benign ultrasonographic characteristics such as hyperechogenicity and a mixed sponge-like aspect, and a concordant cytology, have a negative predictive value of 96.6%. It is, thus, important to examine all nodular lesions and to identify suspicious lesions that need biopsy, especially in multinodular glands. Ultrasonography is also highly sensitive in the identification of suspicious cervical lymph nodes during the follow-up of patients with thyroid carcinoma, even when PCI is negative and serum thyroglobulin (Tg) levels are undetectable. Tg measurement in the needle wash-out content is recommended as this has proven to be more sensitive than cytology in the diagnosis of cervical metastasis, especially where there is liquid content, and it is not affected by the presence of anti-Tg antibodies.

Comparison of whole-body 18F-FDG SPECT and posttherapeutic 131I scintigraphy in the detection of metastatic thyroid cancer

PURPOSE

The usefulness of fluorine 18 fluorodeoxyglucose ((18)F-FDG) imaging in differentiated thyroid cancer (DTC) has been demonstrated by investigators. The aim of this study is to compare the ability of fluorodeoxyglucose (FDG)-single photon emission computed tomography (SPECT) to detect metastatic DTC with posttherapeutic iodine131 ((131)I) scintigraphy.

METHODS

239 patients (78 men, 161 women; age range, 23-76 years, mean 45 years); All patients underwent FDG-SPECT and (131)I whole-body scan.

RESULTS

The sensitivity of (18)F-FDG and (131)I imaging in the patients with high hTg levels is 48.7% (114/234) and 50.4% (118/234) respectively. However, the combined sensitivity of both protocols is 89.7% (210/234). In the patients with (131)I Imaging negative, the sensitivity of (18)F-FDG is 79.3%,but in the patients with (131)I imaging positive, the sensitivity of (18)F-FDG is only 18.6%.

CONCLUSION

This study with (131)I and (18)F-FDG in FDG-SPECT further demonstrates the single study of (131)I whole body scan or (18)F-FDG imaging can not provide a high enough sensitivity for the detection of metastatic thyroid cancer. But, the combined protocols can get better results for the staging of thyroid carcinoma with the alternating uptake of (131)I and (18)F-FDG.

Utilidade da tomografia de emissão de pósitrons com fluoro-deoxiglicose (FDG-PET) na avaliação do câncer de tireóide: uma revisão sistemática

Após o tratamento inicial do câncer tireoidiano, a detecção de prováveis recorrências e/ou metástases se faz através da dosagem de marcadores séricos e estudos de imagem. Essas técnicas podem ser negativas apesar de evidências bioquímicas de doença metastática. A tomografia de emissão de pósitrons com fluorodeoxiglicose (FDG-PET) tem sido proposta como um teste acurado para detectá-la. O objetivo deste estudo é apresentar uma síntese das evidências obtidas através de revisão sistemática sobre a acurácia do FDG-PET na localização de metástases de câncer tireoidiano previamente tratado, nos quais as modalidades convencionais falharam na sua detecção. Foi realizada uma pesquisa bibliográfica no MEDLINE de todos os trabalhos relativos a FDG-PET e carcinoma tireoidiano diferenciado, indexados até setembro de 2005. Foram obtidas 216 citações e 17 trabalhos foram incluídos, 71% publicados a partir de 2000. A sensibilidade da FDG-PET foi elevada, com apenas um trabalho apresentando sensibilidade inferior a 75%. A especificidade, examinada em 12 estudos, foi menor que 75% em 3 estudos. Em 41% dos trabalhos existia pelo menos um teste comparativo com o FDG-PET. Os resultados apontam o FDG-PET como um teste diagnóstico útil para a detecção e localização de metástases do câncer tireoidiano, com implicações diretas no tratamento dos pacientes.

Contemporary Imaging for Thyroid Cancer

Thyroid nodules are extremely common in the adult population of the United States, and the incidence of thyroid cancer continues to increase. Preoperative ultrasonography is a crucial component of the work up of thyroid nodules. Recent studies evaluating (18)F-2-fluoro-2-deoxy-D-glucose-positron-emission-tomography, with or without simultaneous computed tomography imaging, are encouraging for its potential utility in thyroid cancer in patients who have an elevated serum thyroglobulin level and a negative (131)I scan.

The role of PET in follow-up of patients treated for differentiated epithelial thyroid cancers

This article provides an update on the use of 2-[(18)F]-fluoro-2-deoxyglucose PET in the follow-up of patients treated for differentiated thyroid carcinoma (DTC). Although DTC recurrence is principally identified by a detectable basal or TSH-stimulated thyroglobulin level, PET helps to localize recurrent disease in patients with normal (131)I total-body scans and other normal anatomic imaging studies. The sensitivity of PET for localization of recurrence ranges from 45% to 100% according to tumor burden and differentiation. Whether PET should be performed after TSH stimulation is unclear, but several studies have reported an increase in the number of lesions detected by uptake of 2-[(18)F]-fluoro-2-deoxyglucose in this setting. Dependent on a center's approach, PET can alter therapeutic management in 9-51% of cases. Furthermore, PET might have a prognostic impact on survival in patients with metastatic disease and aid clinicians in selecting patients who need closer follow-up or aggressive treatment. PET can, therefore, be used advantageously in the follow-up of patients with DTC and can localize disease in patients with elevated thyroglobulin levels, normal total-body scans, and normal findings on conventional imaging modalities. In patients in whom local treatment is planned, especially those with aggressive pathologic variants of thyroid cancer, PET can exclude distant metastases. In patients with metastatic disease, PET can help to identify patients needing closer follow-up.

Combined PET-CT in the Head and Neck

Positron emission tomography (PET) with 2-[fluorine-18] fluoro-2-deoxy-D-glucose (FDG) is effective for monitoring head and neck cancer. However, lack of anatomic landmarks, variable physiologic FDG uptake, and asymmetric FDG distribution in the neck can confound image interpretation. This is particularly true in the treated neck, where distortion of normal tissue planes makes detection of early disease recurrence difficult with conventional computed tomography (CT) and magnetic resonance imaging. Combined PET-CT helps prevent the misinterpretation of FDG PET findings in patients with head and neck cancer. Superior localization of FDG uptake with this technique can improve diagnostic accuracy and help avoid interpretative pitfalls. In the future, development of tumor-specific ligands will enhance the usefulness of PET-CT in the detection of initial tumors and tumor recurrence, in the evaluation of tumors with low FDG avidity, and in treatment targeting. Furthermore, improved scanner resolution will help address the limitations of PET-CT with respect to small lesions and may make this modality more valuable in initial tumor staging.

Usefulness of fine needle aspiration cytology in the diagnosis of loco-regional recurrence of differentiated thyroid carcinoma

AIM

The aim of our study was to define the usefulness of fine needle aspiration cytology (FNAC) in the assessment of loco-regional recurrence of differentiated thyroid carcinoma (DTC).

METHODS

Among 1182 consecutive patients treated and followed for DTC from 1992 to 2001, we retrospectively analysed 65 FNAC results of patients presenting a suspicion of loco-regional recurrence. Recurrences were proved at histology in 35 cases and by cervical radioiodine uptake on post-therapeutic WBS (whole body scan) in nine cases.

RESULTS

Among the 44 recurrences, FNAC results were malignant, benign and unsatisfactory in 33, two and nine cases, respectively. For the diagnosis of malignancy, FNAC sensitivity was 94%, specificity 100%, positive predictive value 100% and negative predictive value 87%. In the 35 cases where divergent results between diagnostic WBS (37-111MBq (131)I) and Tg level were observed, FNAC assessed the final status in 22 cases (malignant and benign in 17 and five cases, respectively). Of the 12 non-functioning and non-secreting lesions, FNAC diagnosed malignancy in four of the five malignant cases and ruled out malignancy in all seven benign lesions.

CONCLUSION

These results outline the interest of FNAC in the assessment of loco-regional recurrences of DTC, especially when classical follow-up tools such as WBS and/or Tg level are unable to detect the recurrences.