Combining radiomics with thyroid imaging reporting and data system to predict lateral cervical lymph node metastases in medullary thyroid cancer

BACKGROUND

Medullary Thyroid Carcinoma (MTC) is a rare type of thyroid cancer. Accurate prediction of lateral cervical lymph node metastases (LCLNM) in MTC patients can help guide surgical decisions and ensure that patients receive the most appropriate and effective surgery. To our knowledge, no studies have been published that use radiomics analysis to forecast LCLNM in MTC patients. The purpose of this study is to develop a radiomics combined with thyroid imaging reporting and data system (TI-RADS) model that can use preoperative thyroid ultrasound images to noninvasively predict the LCLNM status of MTC.

METHODS

We retrospectively included 218 MTC patients who were confirmed from postoperative pathology as LCLNM negative (n=111) and positive (n=107). Ultrasound features were selected using the Student's t-test, while radiomics features are first extracted from preoperative thyroid ultrasound images, and then a two-step feature selection approach was used to select features. These features are then used to establish three regularized logistic regression models, namely the TI-RADS model (TM), the radiomics model (RM), and the radiomics-TI-RADS model (RTM), in 5-fold cross-validation to determine the likelihood of the LCLNM. The Delong's test and decision curve analysis (DCA) were used to evaluate and compare the performance of the models.

RESULTS

The ultrasound features of margin and TI-RADS level, and a total of 12 selected radiomics features, were significantly different between the LCLNM negative and positive groups (p<0.05). The TM, RM, and RTM yielded an averaged AUC of 0.68±0.05, 0.78±0.06, and 0.82±0.05 in the 5-fold cross-validation dataset, respectively. RM and RTM are statistically better than TM (p<0.05 and p<0.001) according to Delong test. DCA demonstrates that RTM brings more benefit than TM and RM.

CONCLUSIONS

We have developed a joint radiomics-based model for noninvasive prediction of the LCLNM in MTC patients solely using preoperative thyroid ultrasound imaging. It has the potential to be used as a complementary tool to help guide treatment decisions for this rare form of thyroid cancer.

Clinical features and imaging examination assessment of cervical lymph nodes for thyroid carcinoma

BACKGROUNDS

The purpose of this study is to investigate the relationship between clinical characteristics and cervical lymph node metastasis (LNM) in patients with thyroid carcinoma, as well as estimate the preoperative diagnosis values of ultrasound (US) and contrast enhanced computed tomography (CECT) examinations on the neck for detection of cervical LNM in thyroid carcinoma.

METHODS

A retrospective analysis of 3 026 patients with surgically proven thyroid carcinoma was conducted. Patients' clinical characteristics, including gender, age, tumor size, bilateral lesions, multifocality, adenomatous nodules, Hashimoto's thyroiditis (HT), and extrathyroidal extension, were collected to explore their association with cervical LNM in thyroid carcinoma. Preoperative assessments for central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM) were conducted through US and CECT. The diagnostic value of US, CECT and US combined with CECT for detection of LNM located in various cervical compartments was estimated based on the pathological results.

RESULTS

The risk of cervical LNM was higher in thyroid cancer patients who were male, age < 55 years old, tumor size > 10 mm, bilateral lesions, and extrathyroidal extension, while multifocality, adenomatous nodules and HT had no significant effect on LNM. US, CECT and US combined with CECT all had a higher sensitivity to LLNM (93.1%, 57.8%, 95.4%) than to CLNM (32.3%, 29.0%, 43.4%). US and CECT had a high specificity to both CLNM and LLNM (94.3-97.8%).

CONCLUSION

Preoperative clinical characteristics and imaging examinations on patients with thyroid carcinoma are crucial to the evaluation of cervical lymph nodes and conducive to individualizing surgical treatments by clinicians. US combined with CECT are superior to single US or CECT alone in detection of CLNM and LLNM.

Competing-risks model for predicting the prognostic value of lymph nodes in medullary thyroid carcinoma

BACKGROUND

Medullary thyroid carcinoma (MTC) is an infrequent form malignant tumor with a poor prognosis. Because of the influence of competitive risk, there may suffer from bias in the analysis of prognostic factors of MTC.

METHODS

By extracting the data of patients diagnosed with MTC registered in the Surveillance, Epidemiology, and End Results (SEER) database from 1998 to 2016, we established the Cox proportional-hazards and competing-risks model to retrospectively analyze the impact of related factors on lymph nodes statistically.

RESULTS

A total of 2,435 patients were included in the analysis, of which 198 died of MTC. The results of the multifactor competing-risk model showed that the number of total lymph nodes (19-89), positive lymph nodes (1-10,11-75) and positive lymph node ratio (25%-53%,>54%), age (46-60,>61), chemotherapy, mode of radiotherapy (others), tumor size(2-4cm,>4cm), number of lesions greater than 1 were poor prognostic factors for MTC. For the number of total lymph nodes, unlike the multivariate Cox proportional-hazards model results, we found that it became an independent risk factor after excluding competitive risk factors. Competitive risk factors have little effect on the number of positive lymph nodes. For the proportion of positive lymph nodes, we found that after excluding competitive risk factors, the Cox proportional-hazards model overestimates its impact on prognosis. The competitive risk model is often more accurate in analyzing the effects of prognostic factors.

CONCLUSIONS

After excluding the competitive risk, the number of lymph nodes, the number of positive and the positive proportion are the poor prognostic factors of medullary thyroid cancer, which can help clinicians more accurately evaluate the prognosis of patients with medullary thyroid cancer and provide a reference for treatment decision-making.

Surgical selection and prognostic analysis in patients with unilateral sporadic medullary thyroid carcinoma

PURPOSE

The extent of thyroid surgery and cervical lymph node dissection of unilateral sporadic medullary thyroid carcinoma (sMTC) is still controversial, and the aim of this study was to investigate whether hemithyroidectomy was adequate as a locally curative surgery for patients with unilateral sMTC.

METHODS

This study is a retrospective case series of patients with sMTC who underwent curative total thyroidectomy or hemithyroidectomy in our institution from January 2011 to December 2019.

RESULTS

In total, 129 patients who met the inclusion criteria were enrolled including 49 (38.0%) patients who underwent total thyroidectomy and 80 (62.0%) patients who underwent hemithyroidectomy. About 80 (62.0%) patients achieved a biochemical cure (BC), whereas there was no significant difference between two groups in biochemical cure rate (61.2% versus 62.5%, P = 0.885). A logistic regression analysis showed a strong negative correlation between the factors of preoperative calcitonin level and pTNM stage and biochemical cure. In the log-rank test, no significant difference in OS (P = 0.314) and DFS (P = 0.409) was found between the two surgical groups. Lateral cervical lymph node metastasis and pTNM stage were significant prognostic factors affecting DFS in univariate analysis; moreover, absence of biochemical cure, tumor size ≥ 4 cm and lateral cervical lymph node metastasis were independent risk factors of unilateral sMTC patients in our analysis.

CONCLUSION

For patients with unilateral sMTC, hemithyroidectomy was adequate as a locally curative surgery, because the patients underwent total thyroidectomy did not benefit more from it in the aspects of BC/OS/RFS, while the postoperative increasing incidence rate of postoperative hypocalcemia could not improve patients' quality of life.

Clinical Characteristics, Surgical Management, and Prognostic Factors of Medullary Thyroid Carcinoma: A Retrospective, Single-Center Study

Purpose: Medullary thyroid carcinoma (MTC) is a rare neuroendocrine malignancy with relatively early lymphatic metastatic spread. The clinical features of MTC remain controversial owing to the low incidence rate. This study aimed to analyze the clinical characteristics, prognostic factors, and long-term follow-up of MTC. Methods: Medical records of MTC patients treated at our hospital between December 2000 and November 2020 were reviewed retrospectively. Clinicopathologic features of MTC were analyzed using univariate and multivariate analyses. Cumulative survival rates were estimated using the Kaplan-Meier method. Results: In total, 152 patients with MTC were included. The rates of central and lateral lymph node metastases (LNM) were 52.0% and 42.8%, respectively. All patients were followed up with a median follow-up time of 43.5 (17.0−76.3) months. Univariate and multivariate analyses identified two independent factors associated with progressive disease. They were lateral LNM (p < 0.001) and lymph node ratio (LNR) >1/3 (p = 0.009). The 5-, 10-, and 15-year cumulative overall survival (OS) rates of MTC were 88.2%, 83.1%, and 76.2%, respectively. The 5-, 10-, and 15-year cumulative disease-free survival (DFS) rates were 61.8%, 48.6%, and 38.2%, respectively. Patients with stage I, II, and III disease had significantly longer OS and DFS than those with stage IV disease (p < 0.001). Conclusion: MTC is a rare endocrine malignancy and LNM is common. Patients with lateral LNM and LNR >1/3 are more likely to develop progressive disease. The long-term OS rates of MTC are good, but long-term DFS rates are poor.

Lobectomy may be more appropriate for patients with early-stage medullary thyroid cancer older than 60 years old

PURPOSE

Clinical guidelines presently recommend total thyroidectomy for the treatment of medullary thyroid cancer (MTC). This study was aimed to investigate whether lobectomy could be the initial treatment for stage I MTC patients.

METHODS

The retrospective study was based on data from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. The risk factors of survival were estimated by the univariate and multivariate Cox proportional-hazards model. The effect of age on death risk was estimated using restricted cubic splines. Survival curves were constructed according to the Kaplan-Meier method.

RESULTS

A total of 988 stage I MTC patients was included in the study. Among them, 506 (51.2%) MTC patients received lobectomy and 482 (48.8%) received total thyroidectomy. The only independent prognostic factor for overall survival (OS) and disease-specific survival (DSS) was age, according to univariate and multivariate Cox regression analysis. The hazard ratio (HR) increased relatively slowly with age growing under the age of approximately 60 years. However, the death risk of MTC patients began to rise sharply with increasing age above 60 years. For patients under the age of 60, a significant survival difference for OS and DSS was observed between the lobectomy group and total thyroidectomy group (p < 0.05). However, for patients aged above 60, no significant survival difference was observed for OS or DSS (p > 0.05).

CONCLUSION

Total thyroidectomy was an appropriate treatment for stage I MTC patients under the age of 60, which was consistent with the recommendation of the clinical guidelines. However, for those over the age of 60, lobectomy may be explored as a better surgical option. The findings may provide the evidence base for improving the clinical management of stage I MTC patients. Further prospective multicenter clinical studies are needed including information regarding RET status as well as calcitonin and CEA levels.

Feasibility of lateral sentinel lymph node biopsy in medullary thyroid cancer: A surrogate tool for determining prophylactic lateral neck dissection-A pilot study

BACKGROUNDS

This study aimed to evaluate usefulness of lateral sentinel lymph node biopsy (SLNB) in determining lateral neck dissection (LND) of patients with medullary thyroid cancer (MTC).

METHODS

Sixteen patients with MTC were enrolled in the study from January 2013 to June 2019. Intratumoral injection of technetium (Tc)-99m phytate followed by lymphoscintigraphy was performed preoperatively. Lateral sentinel lymph nodes were detected by a collimated gamma probe and underwent frozen analysis. Ipsilateral LND was performed in all patients to assess lateral LN status.

RESULTS

The identification rate of sentinel lymph nodes (SLNs) detected by radioisotope was 87.5% (14 of 16 patients). The sensitivity, specificity, positive predictive value, and negative predictive value of frozen analyses were 66.7%, 100%, 100%, and 91.6%, respectively. Based on final histopathology, however, the diagnostic values of lateral SLNB were all 100%.

CONCLUSIONS

This study showed that lateral SLNB can be a promising surgical tool for decisions on LND in patients with MTC.

Correlation between Ultrasonic Features of Medullary Thyroid Carcinoma and Cervical Lymph Node Metastasis

The aim of this study was to investigate the factors that affect cervical lymph node metastasis (CLNM) in individuals with medullary thyroid carcinoma (MTC) in terms of ultrasonic characteristics and other parameters. Single-factor χ² analysis showed that the ultrasonic characteristics of tumor size >10 mm, unclear boundary, irregular pattern and capsular invasion, as well as pre-operative calcitonin level >302.50 pg/mL (p < 0.001) and age ≤52.50 y (p = 0.036), were risk factors for CLNM in individuals with MTC. Multivariate logistic regression analysis showed that age ≤52.50 y (odds ratio = 3.796; 95% confidence interval, 1.010-14.259; p = 0.048), irregular pattern (odds ratio = 5.262; 95% confidence interval, 1.200-23.084; p = 0.028) and tumor size >10 mm (odds ratio = 7.789; 95% confidence interval, 1.123-54.005; p = 0.038) were independent risk factors for CLNM in individuals with MTC. Individuals with MTC aged ≤52.50 y with an irregular pattern and tumor size >10 mm were more likely to develop CLNM. In addition, those with a pre-operative calcitonin level >302.50 pg/mL were more likely to have CLNM.

Medullary thyroid cancer: molecular factors, management and treatment

Medullary thyroid cancer (MTC) is an infrequent neuroendocrine tumor, which amounts to 3–5% of all thyroid malignancies. Approximately 75–80% of MTCs are sporadic neoplasms. The rest of 20–25% are familial cases that belong to multiple endocrine neoplasia (MEN) syndromes, specifically MEN2 and MEN3. These cases of familial MTC are attributed to an activating germline mutation of a tyrosine kinase receptor gene, the rearranged during transfection (RET) proto-oncogene, located on chromosome 10q11.21. These mutations are also found in some cases of sporadic MTC. This review sets forth in summary the accepted guidelines and approaches regarding diagnosis, management, and treatment of MTC. Surgical resection is the standard care, and an early, prophylactic intervention is performed in genetic cases. Further investigation and understanding of the molecular pathways involved in the growth and advancement of MTC is required in order to provide efficient therapy in cases of progressive disease.

PROGNOSTIC VARIABLES AFFECTING PRIMARY TREATMENT OUTCOME FOR MEDULLARY THYROID CANCER

OBJECTIVE

Identifying prognostic risk factors and determining the efficacy of common surgical treatments is critical to determine optimal treatment strategies for patients with medullary thyroid carcinoma (MTC). The objective of this study was to review a contemporary institutional experience with MTC primary treatment with 2 goals: to identify prognostic factors that impact survival and to study the effect of neck dissection on those outcomes.

METHODS

This study was a retrospective case series of patients with MTC who underwent at least a total thyroidectomy with curative intent. Clinical parameters including tumor and nodal staging with corresponding pathology findings were identified. Survival endpoints included overall survival, disease-free survival, and biochemical cure.

RESULTS

Sixty-seven patients were included. The majority presented with early T-stage disease. Fifty (76%) patients were N0 at presentation. Seventeen (24%) had some evidence of neck disease on clinical examination or imaging. Forty (71%) achieved biochemical cure, and the 5-year biochemical recurrence-free survival for those cases was 86.5%. Among patients who had successful resection of all gross disease, 92% had no evidence of structural disease at 5 years. Overall survival was 91% at 5 years. Increased pre-operative calcitonin (Ct) level, primary tumor size, extrathyroidal extension, and neck metastases decrease the rate of biochemical cure. Larger tumor size increases the risk of structural disease recurrence and biochemical relapse after initial cure. The presence and number of neck metastases correlate with biochemical relapse. The presence of lateral neck nodes (pN1b) does not have different survival implications than centrally confined disease (pN1a).

CONCLUSION

This study shows increasing tumor size, increased Ct level, and cervical metastases are poor prognostic factors. Patients with large tumors, high Ct level, or unfavorable pathologic findings may warrant more aggressive initial treatment, although limitations of the study prevent any conclusion regarding the effect of neck dissection.

ABBREVIATIONS

ATA = American Thyroid Association BRFS = biochemical recurrence-free survival CND = central neck dissection Ct = calcitonin DFS = disease-free survival MTC = medullary thyroid carcinoma OR = odds ratio OS = overall survival pCND = prophylactic CND.

The advantages of extended subplatysmal dissection in thyroid surgery-the "mobile window" technique

PURPOSE

Minimal access thyroidectomy, using various techniques, is widely known, but respective data on thyroidectomy for thyroid cancer with lymphadenectomy is scarce. The present study aims to evaluate the feasability of extended subplatysmal dissection in combination with a small incision ("mobile window" technique).

METHODS

A retrospective study was performed analysing data from 93 patients. All patients suffered from thyroid carcinoma and underwent (total) thyroidectomy, bilateral cervico-central (levels VI and VII) and functional lateral neck dissection (levels II to V) on the side of the malignancy. In group A, consisting of 47 patients, the operation was performed by a traditional Kocher incision (minimal range 6-7 cm), in 46 patients (group B) a mini-incision (≤4 cm) was made. Intra- and postoperative morbidity as well as oncological accuracy were assessed.

RESULTS

There was no significant difference between the two groups comparing postoperative pathological diagnosis, intra- and postoperative complications and the number of removed lymph nodes. However, operating time was slightly longer in group A and thyroid weight was heavier in group B.

CONCLUSIONS

Extended subplatymsal dissection allows thyroidectomy and even lateral lymphadenectomy for thyroid carcinoma via "mobile" mini-incision. The procedure is safe, of equivalent oncological accuracy compared to traditional incision and the cosmetic results are excellent.

A cohort study on 10-year survival of sporadic medullary thyroid carcinoma with somatic RET mutation

Somatic rearranged during transfection (RET) mutations are reported in 40-50% of sporadic medullary thyroid carcinoma (sMTC) patients with prognostic significance. As there is a lack of somatic RET mutations reported previously for the Taiwanese population, we tried to assess the presence of somatic RET mutations and evaluate the potential outcome predictors for our sMTC patients. We collected data from seven sMTC patients from the years 1997 to 2005 and analyzed their clinic-pathological features up to 2015. All patients were still alive to follow up for 11∼18 years. Tumor DNAs were extracted to assess exons 10-11 and 13-16, and the intron-exon boundaries of the RET gene. Six cases (86%) were screened positive of somatic RET gene mutations in hotspot regions, one at M918T, one at C620R, and three at C634S, with another two rare mutations at L629Q and V642I. Comparing the current tumor, node, metastases staging system, the 10-year survival outcomes for our sMTC patients was not predicted by serum calcitonin and/or carcinoembryonic antigen, surgical extent, and presence of the somatic RET gene mutations. The small cohort demonstrated a relatively good outcome of sMTC patients to survive >10 years. In addition, intensive treatment with total thyroidectomy with extensive neck lymph node dissection seemed to be the critical determinant of better survival outcome for sMTC patients.

A Carbon Nanoparticle Lymphatic Tracer Protected Parathyroid Glands During Radical Thyroidectomy for Papillary Thyroid Non-Microcarcinoma

The study assessed the role of an activated carbon nanoparticle lymphatic tracer in reducing unintentional damage to the parathyroid glands during thyroidectomy for papillary thyroid non-microcarcinoma diagnosed intraoperatively by cryosections. A total of 103 patients with papillary thyroid non-microcarcinomas diagnosed by intraoperative cryosection were randomly assigned to receive routine radical thyroidectomy or radical thyroidectomy following administration of activated carbon nanoparticle lymphatic tracer to the contralateral thyroid, at the department of Thyroid Surgery, Sun Yat-sen Memorial Hospital (Guangzhou, China), between January 2012 and May 2013. The success of level VI lymphadenectomy and postoperative parathyroid function were compared. Administration of the activated carbon nanoparticle lymphatic tracer did not affect the frequency of recovered lymph nodes containing metastases; however, it did significantly reduce the incidence of permanent and transient hypoparathyroidism from 2 to 0 and 18 to 6, and reduced the mean recovery time for transient hypoparathyroidism from 57.0 days to 22.3 days. Administration of activated carbon nanoparticles to the contralateral thyroid after intraoperative cryosections did not contribute to lymphadenectomy for papillary thyroid non-microcarcinoma, but significantly protected parathyroid functions. This approach could decrease the morbidity of radical thyroidectomy and the occurrence of hypoparathyroidism.

Surgery for lymph node metastases of medullary thyroid carcinoma: A review

Medullary thyroid carcinoma (MTC) is a neuroendocrine malignancy of the thyroid C cells that occurs in hereditary and sporadic clinical settings. Metastatic spread commonly occurs to cervical and mediastinal lymph nodes. MTC cells do not concentrate radioactive iodine and are not sensitive to hormonal manipulation, and therefore surgery is the most effective option for curative therapy, reduction in tumor burden, or effective palliation. In patients undergoing preventative surgery for hereditary MTC, central lymph node dissection should be considered if the calcitonin level is elevated. Preservation of parathyroid function in these young patients is of paramount importance. In patients with established primary tumors, systematic surgical removal of lymph node basins (compartmental dissection) should be guided by ultrasound mapping of lymph node metastases and level of serum calcitonin. A "berry-picking" approach is discouraged. Newly approved targeted molecular therapies offer wider treatment options for patients with progressive or metastatic disease.

Surgery for lymph node metastases of medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a neuroendocrine malignancy of the thyroid C cells, and can commonly spread to cervical and mediastinal lymph nodes. MTC cells do not concentrate radioactive iodine and are not sensitive to hormonal manipulation, and therefore surgery is the only effective option for curative therapy, reduction in tumor burden or effective palliation. In patients undergoing preventative operations for hereditary MTC, central lymph node dissection should be considered if the calcitonin level is above 40 pg/ml. Systematic removal of at-risk or involved lymph node compartments should be performed in all patients with palpable primary tumors and recurrent disease, and a ‘berry-picking’ approach should be avoided.