Preoperative Prediction of Cervical Lymph Node Metastasis Using Primary Tumor SUVmax on 18F-FDG PET/CT in Patients with Papillary Thyroid Carcinoma

Enhanced staging of differentiated thyroid carcinoma: integrating [18F]FDG digital PET/CT with neck ultrasound

PURPOSE

Accurate initial staging of differentiated thyroid carcinoma (DTC) is paramount to avoid disease persistence or relapses. Neck ultrasound (US) is the gold-standard examination for lymph node staging; however, it might miss the central compartment ones. [18F]FDG PET/CT has been used to characterise unclear or suspicious thyroid nodules and can also identify nodal disease. This study tested the diagnostic efficacy of a combined approach, including digital [18F]FDG PET/CT of the cervical region and neck US in DTC staging.

METHODS

We retrospectively evaluated consecutive patients treated at our centre with high-risk thyroid who had had a neck US and a neck digital [18F]FDG PET/CT before surgery and at least one year of follow-up. Diagnostic parameters, including sensitivity (Se) and accuracy (Acc), were compared across US alone, [18F]FDG PET/CT alone, and the combined approach using a patient-based analysis (PBA); Se was also tested employing a lesion analysis (LBA). Clinical and SUV parameters were compared with the histology and the one-year outcome via a logistic regression model.

RESULTS

Eighty-two patients (61 females) were included. At the PBA, the combined approach was superior to US alone regarding Se (44% vs 19%, p < 0.05) and Acc (80% vs 72%, p < 0.05) in the central compartment nodes. At the LBA, the combined approach was superior to either method overall (43%, 37%, and 36% for combined, [18F]FDG, and US, respectively, p < 0.01) and to US in the central nodes (25% vs 14%, p < 0.01). SUVratio was an independent predictor of histologically aggressive DTC variants (p = 0.009), central compartment metastases (p = 0.04), and incomplete response at follow-up (p = 0.004).

CONCLUSIONS

The combined cervical [18F]FDG PET/CT / US approach improves the initial staging and harbours valuable prognostic information for DTC patients.

Does high [18F]FDG uptake always mean poor prognosis? Colon cancer with high-level microsatellite instability is associated with high [18F]FDG uptake on PET/CT

OBJECTIVES

High-level microsatellite instability (MSI-high) is generally associated with higher F-18 fluorodeoxyglucose ([18F]FDG) uptake than stable microsatellite (MSI-stable) tumors. However, MSI-high tumors have better prognosis, which is in contrast with general understanding that high [18F]FDG uptake correlates with poor prognosis. This study evaluated metastasis incidence with MSI status and [18F]FDG uptake.

METHODS

We retrospectively reviewed 108 right-side colon cancer patients who underwent preoperative [18F]FDG PET/CT and postoperative MSI evaluations using a standard polymerase chain reaction at five Bethesda guidelines panel loci. The maximum standard uptake value (SUVmax), SUVmax tumor-to-liver ratio (TLR), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of the primary tumor were measured using SUV 2.5 cut-off threshold. Student's t-test or Mann-Whitney U test was performed for continuous variables, and χ2 test or Fisher's exact test was performed for categorical variables (p value of  < 0.05 for statistical significance). Medical records were reviewed for metastasis incidence.

RESULTS

Our study population had 66 MSI-stable and 42 MSI-high tumors. [18F]FDG uptake was higher in MSI-high tumors than MSI-stable tumors (TLR, median (Q1, Q3): 7.95 (6.06, 10.54) vs. 6.08 (4.09, 8.82), p = 0.021). Multivariable subgroup analysis demonstrated that higher [18F]FDG uptake was associated with higher risks of distant metastasis in MSI-stable tumors (SUVmax: p = 0.025, MTV: p = 0.008, TLG: p = 0.019) but not in MSI-high tumors.

CONCLUSION

MSI-high colon cancer is associated with high [18F]FDG uptake, but unlike MSI-stable tumors, the degree of [18F]FDG uptake does not correlate with the rate of distant metastasis.

CLINICAL RELEVANCE STATEMENT

MSI status should be considered during PET/CT assessment of colon cancer patients, as the degree of [18F]FDG uptake might not reflect metastatic potential in MSI-high tumors.

KEY POINTS

• High-level microsatellite instability (MSI-high) tumor is a prognostic factor for distant metastasis. • MSI-high colon cancers had a tendency of demonstrating higher [18F]FDG uptake compared to MSI-stable tumors. • Although higher [18F]FDG uptake is known to represent higher risks of distant metastasis, the degree of [18F]FDG uptake in MSI-high tumors did not correlate with the rate at which distant metastasis occurred.

Diagnostic value of multiple diagnostic methods for lymph node metastases of papillary thyroid carcinoma: A systematic review and meta-analysis

OBJECTIVE

This study compared the diagnostic value of various diagnostic methods for lymph node metastasis (LNM) of papillary thyroid carcinoma (PTC) through network meta-analysis.

METHODS

In this experiment, databases such as CNKI, Wanfang, PubMed, and Web of Science were retrieved according to the Cochrane database, Prisma, and NMAP command manual. A meta-analysis was performed using STATA 15.0, and the value of the surface under the cumulative ranking curve (SUCRA) was used to determine the most effective diagnostic method. Quality assessments were performed using the Cochrane Collaboration's risk of bias tool, and publication bias was assessed using Deeks' funnel plot.

RESULTS

A total of 38 articles with a total of 6285 patients were included. A total of 12 diagnostic methods were used to study patients with LNM of PTC. The results showed that 12 studies were direct comparisons and 8 studies were indirect comparisons. According to the comprehensive analysis of the area of SUCRA, US+CT(86.8) had the highest sensitivity, FNAC had the highest specificity (92.4) and true positive predictive value (89.4), and FNAC+FNA-Tg had higher negative predictive value (99.4) and accuracy (86.8). In the non-invasive method, US+CT had the highest sensitivity, and the sensitivity (SEN) was [OR=0.59, 95% confidence interval (CI): (0.30, 0.89]. Among the invasive methods, the combined application of FNAC+FNA-Tg had higher diagnostic performance. The sensitivity was [OR=0.62, 95% CI: (0.26, 0.98)], the specificity (SPE) was [OR=1.12, 95% CI: (0.59, 1.64)], the positive predictive value was [OR=0.98, 95% CI: (0.59, 1.37)], the negative predictive value was [OR=0.64, 95% CI (0.38, 0.90)], and the accuracy was [OR=0.71, 95% CI: (0.31, 1.12)].

CONCLUSION

In the non-invasive method, the combined application of US+CT had good diagnostic performance, and in the invasive method, the combined application of FNAC+FNA-Tg had high diagnostic performance, and the above two methods were recommended.

Prediction of Cervical Lymph Nodes Metastasis in Papillary Thyroid Carcinoma (PTC) Using Nodal Staging Score (NSS)

Background

Cervical lymph node metastasis is commonly seen in papillary thyroid carcinoma. Surgery is the preferred treatment for PTC with cervical lymph node metastasis. There is no alternate ultrasound, neck CT, and thyroglobulin (Tg) methods to assess the occult lymph node metastasis. For moderate-and high-risk PTC, the number of lymph nodes to be dissected should be increased to remove the occult lymph node metastasis.

Objective

This study was designed to develop a nodal staging score model to predict the likelihood of lymph node metastasis in papillary thyroid carcinoma (PTC), and further guide the treatments. Material and Methods. Data were collected from the SEER database. Patients with PTC from 2000 to 2005 were selected. The beta-binomial model was adopted to establish a nodal staging score (NSS)-based model. The NSS-based model was built according to gender, age, extrathyroidal invasion, tumor multifocality, tumor size, and T stage of the patients. A total of 12,431 PTC patients were included in our study. Various types of lymph nodes were examined based on various categories (incidence, risk assessment) to evaluate the results.

Results

5,959 (47.9%) patients in the study were positive and 6,472 (52.1%) were confirmed negative for lymph node metastasis. The corrected incidence of lymph node metastasis was higher than that of direct calculation, regardless of the factors that affected lymph node metastasis. There were significant differences in the OS of PTC patients among the four groups and T stage (p is less than 0.05), indicating that cervical lymph node metastasis would have an impact on the prognosis of patients.

Conclusion

In conclusion, an NSS-based model base on a variety of clinicopathological factors can be used to predict lymph node metastasis. It is important to evaluate the risk of occult lymph node metastasis in the treatment of PTC.. Since, this statistical model can describe the risk of occult lymph node metastasis in patients; therefore, it can be used as basis for decision-making related to the number of lymph nodes that can be dissected in operations.

Radiomics Profiling Identifies the Value of CT Features for the Preoperative Evaluation of Lymph Node Metastasis in Papillary Thyroid Carcinoma

Background: The aim of this study was to identify the increased value of integrating computed tomography (CT) radiomics analysis with the radiologists’ diagnosis and clinical factors to preoperatively diagnose cervical lymph node metastasis (LNM) in papillary thyroid carcinoma (PTC) patients. Methods: A total of 178 PTC patients were randomly divided into a training (n = 125) and a test cohort (n = 53) with a 7:3 ratio. A total of 2553 radiomic features were extracted from noncontrast, arterial contrast-enhanced and venous contrast-enhanced CT images of each patient. Principal component analysis (PCA) and Pearson’s correlation coefficient (PCC) were used for feature selection. Logistic regression was employed to build clinical–radiological, radiomics and combined models. A nomogram was developed by combining the radiomics features, CT-reported lymph node status and clinical factors. Results: The radiomics model showed a predictive performance similar to that of the clinical–radiological model, with similar areas under the curve (AUC) and accuracy (ACC). The combined model showed an optimal predictive performance in both the training (AUC, 0.868; ACC, 86.83%) and test cohorts (AUC, 0.878; ACC, 83.02%). Decision curve analysis demonstrated that the combined model has good clinical application value. Conclusions: Embedding CT radiomics into the clinical diagnostic process improved the diagnostic accuracy. The developed nomogram provides a potential noninvasive tool for LNM evaluation in PTC patients.

KSNM60 in Nuclear Endocrinology: from the Beginning to the Future

Nuclear endocrinology is the main ignitor for founding the Korean Society of Nuclear Medicine (KSNM) in the early 1960s by outstanding pioneering medical doctors. Management of thyroid diseases required nuclear medicine technology in the early days of the KSNM and was rapidly developed by advancements in nuclear medicine technology. Nuclear thyroidology remains one of the main clinical applications in nuclear medicine worldwide. Nuclear medicine technology provides essential information for diagnosing and assessing diseases of the parathyroid glands, pituitary gland, and neuroendocrine tumors (NETs). In addition, therapeutic nuclear medicine is essential for managing nonresectable NETs. Nuclear endocrinology remains a major section in clinical nuclear medicine, and members of the KSNM have contributed to progressing better management of benign and malignant endocrine diseases. This review summarizes the historical activities and milestone contributions to nuclear endocrinology made by the members of the KSNM over the past 60 years to congratulate the KSNM on its 60-year anniversary.

Real-World Evidence on the Sensitivity of Preoperative Ultrasound in Evaluating Central Lymph Node Metastasis of Papillary Thyroid Carcinoma

INTRODUCTION

Guidelines for prophylactic dissection in clinical central negative node (cN0) of papillary thyroid carcinoma vary among different countries due to the uncertainty on the benefit of dissection. The Chinese guidelines recommend prophylactic central compartment lymph node dissection (pCLND) under professional technology. Preoperative ultrasound (US) evaluation of central lymph node determines the surgical strategy used. Sensitivity differs significantly when US is conducted by different physicians even in diverse hospitals. In this study, the aim was to explore why the Chinese guidelines were different from the America Thyroid Association (ATA) guidelines through the real-world evidence on the preoperative diagnosis of cN0.

METHODS

Preoperative US and surgical pathology data for 1,015 patients with PTC attending 13 Grade-A tertiary hospitals in 2017 were collected. A retrospective analysis using US assessment of CLNM was the conducted to explore the benefits of this approach in China. US physicians in our hospital were trained on scanning the thyroid gland and its regional lymph nodes in normalization. Data of 1,776 patients were collected under the same condition from 2012 to 2017, whose ultrasonography was performed by diverse physicians and doctors. Further, data of 339 patients evaluated by the same sonographer and operated by the same surgical team was collected between 2015 and 2017. In this set of data, US combined CT versus US alone was compared. Patients were grouped into metastasis group and non-metastasis group based on postoperative pathological diagnosis of CLNM. Diagnostic efficacy of US was evaluated.

RESULTS

A total of 925 patients who underwent preoperative ultrasonography in central lymph node, including 825 cases who underwent thyroidectomy and central lymph node dissection were included in this study. The sensitivity of ultrasonography in detecting CLNM was 23.18%, with occult metastasis rate of 40.8%. Data for 1,776 patients comprising paired ultrasonic report and pathological report were collected in our hospital, whose physicians underwent standardized training. The sensitivity was 37.58%. Furthermore, specialized evaluation showed high sensitivity in US/CT (84.58%) than US (58.21%) alone.

CONCLUSION

Although the sensitivity of US could be enhanced by standardized training and combination with CT, the prevalence of low sensitivity of US in real-world multicenter data and the high occult metastasis rate indicated that the Chinese guidelines were based on the current conditions.

The Use of 18F-FDG PET/CT in Patients with Recurrent Differentiated Thyroid Cancer

Objectives:

¹⁸Fluorine-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) is used to monitor the recurrence in thyroid cancer patients when there is suspicion of metastases. De-differentiated lesions become ¹⁸F-FDG avid with a more aggressive clinical course. The aim of this study was to investigate the use of ¹⁸F-FDG PET/CT in differentiated thyroid cancer.

Methods:

Forty-six patients, either with a negative radioiodine scan or clinical progression and suspicions for metastases with differentiated thyroid cancer that were referred to our department for ¹⁸F-FDG PET/CT scan and evaluated retrospectively. PET/CT findings were correlated with clinical and histopathological findings, serum thyroglobulin (Tg), and anti-Tg levels.

Results:

Twenty-six patients (56.2%) were positive for recurrence in ¹⁸F-FDG PET/CT images. Positive ¹⁸F-FDG PET/CT findings were significantly correlated with the disease stage and Tg levels. Maximum standardized uptake value did not correlate with other findings or patients’ profiles. The cut-off value for Tg was at 52.5 ng/mL having 73.08% sensitivity, 75% specificity, 79.17% positive predictive value, and 68.18% negative predictive value for ¹⁸F-FDG PET/CT imaging.

Conclusion:

¹⁸F-FDG PET/CT is useful for detecting recurrence in differentiated thyroid cancer. Increased Tg levels and stage of the disease were significantly correlated with ¹⁸F-FDG positivity. ¹⁸F-FDG positivity may also provide information about the de-differentiation process that may support the treatment plan.

Diagnostic values of F-18 FDG PET or PET/CT, CT, and US for Preoperative Lymph Node Staging in Thyroid Cancer: A Network Meta-Analysis

OBJECTIVE

This study compared the diagnostic performance of three different imaging modalities for preoperative lymph node (LN) staging in thyroid cancer patients, using a network meta-analysis (NMA).

METHODS

PubMed and Embase were searched to identify studies evaluating the performance of F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET or PET/CT), computed tomography (CT), and ultrasonography (US) for preoperative LN staging in thyroid cancer patients. The NMA included both patient- and lesion-based analyses. The surface under the cumulative ranking curve (SUCRA) values was used to decide on the most effective diagnostic method.

RESULTS

A total of 3,571 patients from 19 direct comparison studies using three different imaging modalities for preoperative LN staging in thyroid cancer patients were included. US showed the highest SUCRA values for positive predictive values (PPV), negative predictive values (NPV), and accuracy in detection of all cervical LN metastasis. F-18 FDG PET or PET/CT and US showed the highest SUCRA values for PPV and sensitivity, respectively, for central LN, and the highest SUCRA value of specificity and sensitivity, respectively, for lateral LN.

CONCLUSION

The results from this NMA indicate that F-18 FDG PET or PET/CT, CT, and US have complementary diagnostic roles for preoperative staging in thyroid cancer patients.

ADVANCES IN KNOWLEDGE

Using NMA, we comprehensively compared the different diagnostic values and limitations of F-18 FDG PET or PET/CT, CT, and US for the preoperative LN staging in thyroid cancer patients.

Diagnostic role of F-18 FDG PET/CT for preoperative lymph node staging in thyroid cancer patients; A systematic review and metaanalysis

PURPOSE

Although ultrasonography (US) is a standard technique for the assessment of cervical lymph node (LN) metastasis, the role of F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) is increasingly reported. The purpose of this study is to assess the diagnostic accuracy of F-18 FDG PET-CT for detection of cervical LN metastasis in thyroid cancer (TCa) patients through a meta-analysis.

PATIENTS AND METHODS

The PubMed, Cochrane Database, and Embase from the earliest available date of indexing through September 31, 2019, were searched for studies evaluating the diagnostic performance of F-18 FDG PET-CT for detection of LN metastasis in TCa. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic curves.

RESULTS

Across 9 studies (759 patients), the pooled sensitivity for F-18 FDG PET-CT for all cervical LN metastasis in TCa was 0.30 (95% CI; 0.26-0.35) a pooled specificity of 0.94. For central LN metastasis, the pooled sensitivity was 0.28 (95% CI; 0.21-0.34) and a pooled specificity was 0.87 (95% CI; 0.83-0.90). For lateral LN metastasis, the pooled sensitivity was 0.56 (95% CI; 0.50-0.62) and a pooled specificity was 0.94.

CONCLUSIONS

F-18 FDG PET-CT shows a low sensitivity and high specificity for the detection of metastatic LNs in patients with TCa. The current data suggests that F-18 FDG PET-CT is not indicated in the work up of patients with thyroid cancer or biochemical evidence of recurrent disease.

Nomogram using F-18 fluorodeoxyglucose positron emission tomography/computed tomography for preoperative prediction of lymph node metastasis in gastric cancer

BACKGROUND

Lymph node (LN) metastasis is an important prognostic factor in patients with gastric cancer (GC). However, the evaluation of LN metastasis status in the preoperative setting is not accurate. Therefore, precise preoperative prediction of LN metastasis status is crucial for optimal treatment in patients with GC.

AIM

To develop a preoperative nomogram for LN metastasis using F-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) and preoperative laboratory test findings in GC.

METHODS

In this study, the data of 566 GC patients who underwent preoperative F-18 FDG PET/CT and subsequent surgical resection were analyzed. The LN metastasis prediction model was developed in the training cohort and validated in the internal validation cohort. Routine preoperative laboratory tests, including albumin and carbohydrate antigen (CA) 19-9 were performed in all patients. Univariate and multivariable logistic regression was performed to validate the preoperative predictive indicators for LN metastasis.

RESULTS

Of the 566 patients, 232 (41%) had confirmed histopathologic LN metastasis. Univariate logistic regression revealed that the tumor location, blood hemoglobin, serum albumin levels, neutrophil to lymphocyte ratio, platelet to lymphocyte ratio, CA 19-9, maximum standardized uptake value (SUVmax) of the primary tumor (T_SUVmax), and SUVmax of LN (N_SUVmax) were significantly associated with LN metastasis. In multivariate analysis, T_SUVmax (OR = 1.08; 95%CI: 1.02–1.15; P = 0.011) and N_SUVmax (OR = 1.49; 95%CI: 1.19–1.97; P = 0.002) were found to be significant predictive factors for LN metastasis. The LN metastasis prediction model using T_SUVmax, N_SUVmax, serum albumin, and CA 19-9 yielded an area under the curve (AUC) of 0.733 (95%CI: 0.683–0.784, P = 0.025) in the training cohort and AUC of 0.756 (95%CI: 0.678–0.833, P < 0.001) in the test cohort.

CONCLUSION

T_SUVmax and N_SUVmax measured by preoperative F-18 FDG PET/CT are independent predictive factors for LN metastasis in GC.

Select Group of Patients Might Benefit From Prophylactic Central Lymph Node Dissection in Clinically Node Negative Papillary Thyroid Microcarcinoma

Objective

The aim of this study was to identify predictive factors for pathologic central lymph node metastasis (CLNM) in patients with clinically negative CLNM (cN0) papillary thyroid microcarcinoma (PTMC) to suggest a specific group of cN0 PTMC patients who benefit from prophylactic central lymph node dissection (CLND).

Background

PTMC have excellent prognosis, however, 8% have recurrent disease. Recurrence is associated with regional lymph node metastasis. It has been reported that pathologic CLNM is found in 30 to 65% of cN0 PTMC patients. However, prophylactic CLND for cN0 PTMC remains controversial.

Methods

We reviewed the records of papillary thyroid carcinoma patients with a tumor size on preoperative ultrasonography (US) of ≤10 mm and negative CLNM on preoperative physical examination, US, and positron emission tomography/computed tomography (PET/CT), who underwent total thyroidectomy or thyroid lobectomy with prophylactic CLND between April 2010 and February 2013. In total, 163 patients were included. We evaluated the relationship between preoperatively assessable factors including age, gender, body mass index, preoperative metformin use, primary tumor size through preoperative US, the maximum standardized uptake value (SUVmax) of the primary tumor through preoperative PET/CT, and the bilaterality of the primary tumor and pathologic CLNM.

Results

A SUVmax of the primary tumor of &gt;3 was an independent preoperatively assessable factor predictive of pathologic CLNM in cN0 PTMC patients.

Conclusions

Prophylactic CLND might be considered in cN0 PTMC patients with a SUVmax of the primary tumor of &gt; 3 to reduce the risks of residual CLNM and recurrence.

Efficacy of 18F-fluorodeoxyglucose PET/CT for Detecting Lymph Node Metastasis in Papillary Thyroid Carcinoma

Objective

To evaluate the efficacy of preoperative ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for detecting cervical lymph node (LN) metastasis in papillary thyroid carcinoma (PTC).

Study Design

Case series with chart review.

Setting

University tertiary care facility.

Subjects and Methods

We retrospectively compared the pathologic results for 409 cervical LN levels in 140 patients who underwent thyroidectomy and central neck dissection with/without lateral neck dissection with the findings of preoperative PET/CT, ultrasonography (US), and CT. We judged LN metastasis in PET/CT using the maximum standardized uptake value (SUVmax) at the optimal cutoff value in receiver operating characteristic curves and compared the sensitivity, specificity, and diagnostic accuracy of the 3 imaging tools.

Results

At all neck levels (central and lateral compartments), PET/CT had a sensitivity of 57.5%, specificity of 68.6%, and diagnostic accuracy of 63.6% when the cutoff value of SUVmax was 1.125. The corresponding values were 59.1%, 90.6%, and 76.3%, respectively, for US and 53.8%, 91.9%, and 74.6% for CT. In the central compartment (level VI), sensitivity, specificity, and diagnostic accuracy were 48.9%, 67.4%, and 59.9% for PET/CT (cutoff SUVmax 1.125); 47.8%, 96.3%, and 76.7% for US; and 41.3%, 97.0%, and 74.4% for CT, respectively. In the lateral compartment (levels II-V), the corresponding values of sensitivity, specificity, and diagnostic accuracy were 70.2%, 69.3%, and 69.8% for PET/CT (cutoff SUVmax 1.055); 70.2%, 81.8%, and 75.8% for US; and 65.9%, 84.1%, and 74.7% for CT.

Conclusion

PET/CT is less effective as a preoperative diagnostic tool for detecting cervical lymph node metastasis in PTC than US or CT.

Functional visceral fat activity evaluated by preoperative F-18 FDG PET/CT predicts regional lymph node metastasis in differentiated thyroid cancer

OBJECTIVE

We investigated the predictive role of functional visceral fat activity evaluated by preoperative F-18 FDG PET/CT for regional lymph node metastasis in patients with differentiated thyroid cancer.

DESIGN AND PATIENTS

Fifty-eight patients with newly diagnosed differentiated thyroid cancer were enrolled in this study, retrospectively (men 14; women 44; age 53 ± 14.5). They all received preoperative F-18 FDG PET/CT and surgery. Functional visceral fat activity was defined as maximum standardized uptake value (SUVmax) of visceral fat divided by SUVmax of subcutaneous fat (V/S ratio). Pathology results were confirmed through the surgical specimens.

RESULTS

The patients with regional lymph node metastasis showed higher functional visceral fat activity (V/S ratio) than the patients without regional lymph node metastasis (2.12 ± 0.6 vs 1.62 ± 0.34, P = .001). V/S ratio of 1.78 was suggested as an optimal cut-off value for predicting regional lymph node metastasis (sensitivity; 70.3%, specificity; 83.3%, area under the curve; 0.778, P < .0001). Furthermore, functional visceral fat activity was significantly associated with regional lymph node metastasis in patients with differentiated thyroid cancer by univariate and multivariate analyses.

CONCLUSIONS

Functional visceral fat activity significantly affects the regional lymph node metastasis status in patients with differentiated thyroid cancer. Furthermore, it may also be useful to predict regional lymph node metastasis.

CONSORT-Independent prognostic value of asphericity of pretherapeutic F-18 FDG uptake by primary tumors in patients with breast cancer

BACKGROUND

The aim of this study was to evaluate the prognostic implication of asphericity (ASP); spatial irregularity; of pretherapeutic F 2-deoxy-2-fluoro-D-glucose (F FDG) tumor uptake in patients with invasive ductal carcinoma (IDC) of the breast.

METHODS

One hundred thirty-one female IDC patients (mean age = 48.1 ± 10.4 years), with pathological tumor size greater than 2 cm were retrospectively evaluated using F FDG positron emission tomography/computed tomography (PET/CT). ASP of F FDG distribution was calculated on the basis of the deviation of the tumor shape from spherical symmetry. Progression-free survival (PFS) was predicted on the basis of the univariate and multivariate analyses of the measured clinicopathologic factors and metabolic PET parameters [maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG)].

RESULTS

The PFS rate among the 131 patients was 90.1%. The mean follow-up time was 50 months for the entire study cohort and 26 months for the patients with recurrent disease. It is evident from the univariate analysis that N stage, hormonal receptor (Estrogen, ER/Progesterone, PR) status, MTV (≤4.2 mL), and ASP (≤15.1%) affected the PFS. Hazard ratios (HRs) estimated from the multivariate Cox regression analysis show that N stage (HR = 17.6), ASP (HR = 11.9), and hormonal receptor status (HR = 6.9) were independent prognostic factors in predicting PFS. In the subgroup of patients with lymph node metastasis, ASP (HR = 10.9) and hormonal receptor status (HR = 9.1) were independent prognostic factors for PFS.

CONCLUSION

ASP of F FDG uptake is an independent predictor of outcome in IDC patients, and can be used for prognostic stratification.

Predictive Value of 18F-FDG PET/CT for Axillary Lymph Node Metastasis in Invasive Ductal Breast Cancer

BACKGROUND

This study assessed whether primary tumor maximum standardized uptake value (pSUV_max) measured by ¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) could improve the prediction of axillary lymph node (ALN) metastasis in invasive ductal breast cancer (IDC).

METHODS

In this study, 128 IDC patients who underwent pretreatment ¹⁸F-FDG PET/CT and surgical resection of primary tumor with sentinel lymph node biopsy, ALN dissection, or both were analyzed. All the patients were classified as five molecular subtypes. The optimal cutoff values of pSUVmax for all the patients and each molecular subtype for the prediction of ALN metastasis were determined using receiver operating characteristic (ROC) analysis. Furthermore, the prognostic accuracy of ALN metastasis was assessed using c-statistics.

RESULTS

The findings showed ALN metastasis in 52 patients (40.6%). The ¹⁸F-FDG PET/CT procedure had a sensitivity of 48.1% and a specificity of 94.7% for ALN metastasis. In the ROC analysis of pSUVmax for ALN metastasis, the optimal cutoff value was 3.9 for all the patients, 2.8 for the luminal A subtype, 3.3 for the luminal B (human epidermal growth factor receptor 2 [HER2]-negative) subtype, 5.3 for the luminal B (HER2-positive) subtype, 12.7 for the HER2-positive subtype, and 11.5 for the triple-negative subtype. A predictive ALN metastasis model using nodal ¹⁸F-FDG uptake finding gave a c-statistic of 0.714, and a model combination of nodal ¹⁸F-FDG uptake finding with pSUV_max of all the patients gave a c-statistic of 0.736 (P = 0.3926). However, the combination of nodal the ¹⁸F-FDG uptake finding with the pSUV_max of each molecular subtype gave a c-statistic of 0.791 (P = 0.0047).

CONCLUSIONS

Combining the pSUV_max of each molecular subtype with the nodal ¹⁸F-FDG uptake finding can improve the prediction of ALN metastasis in IDC.

Diagnostic Value of Semiquantitative Analysis of 99mTechnetium-Methoxyisobutylisonitrile (99mTc-MIBI) Imaging in Predicting Early-Stage Cervical Lymph Node Metastasis of Thyroid Carcinoma

Background

The aim of this study was to evaluate the value of semiquantitative analysis (SQA) of ^99mTc-MIBI imaging in predicting early-stage cervical lymph node metastasis (CLNM) in thyroid carcinoma (TC).

Material/Methods

TC patients (n=106) undergoing surgical resection and histopathological examination were enrolled. All patients received ^99mTc-MIBI imaging prior to surgery. P-glycoprotein (P-gp) expression was detected by PT-PCR and immunohistochemistry. With pathological results as the criterion standard, the diagnostic efficiency of ^99mTc-MIBI imaging in predicting early-stage CLNM was evaluated. The correlation of P-gp with ^99mTc-MIBI imaging was investigated. Logistic regression analysis was applied for analyzing the factors affecting early-stage CLNM.

Results

The detection rate and misdiagnosis rate of ^99mTc-MIBI imaging for early-stage CLNM diagnosis were 87.3% and 12.7%, respectively. Receiver operating characteristic (ROC) curve analysis showed an accuracy of ^99mTc-MIBI imaging of 85.85%. Preoperative ^99mTc-MIBI scan showed statistical differences between metastasis and non-metastasis groups in early and delayed T/NT and washout rate (all P<0.05). The percentage of P-gp-expressing cells and the expression rate of P-gp gene both exhibited statistical differences between metastasis and no-metastasis groups (both P<0.05). Tumor diameter, lesion distribution, the percentage of P-gp-expressing cells, and the expression rate of P-gp gene were risk factors for CLNM (all P<0.05).

Conclusions

^99mTc-MIBI imaging has value in qualitative diagnosis of early-stage CLNM in TC. Tumor diameter, lesion distribution, the percentage of P-gp-expressing cells, and the expression rate of P-gp gene were risk factors for CLNM.