Salvage surgery for structural local recurrence of papillary thyroid cancer: recurrence patterns and surgical outcome

Model Based on Ultrasound Radiomics and Machine Learning to Preoperative Differentiation of Follicular Thyroid Neoplasm

OBJECTIVES

To evaluate the value of radiomics based on ultrasonography in differentiating follicular thyroid carcinoma (FTC) and follicular thyroid adenoma (FTA) and construct a tool for preoperative noninvasive predicting FTC and FTA.

METHODS

The clinical data and ultrasound images of 389 patients diagnosed with FTC or FTA postoperatively were retrospectively analyzed at 3 institutions from January 2017 to December 2023. Patients in our hospital were randomly assigned in a 7:3 ratio to training cohort and validation cohort. External test cohort consisted of data collected from other 2 hospitals. Radiomics features were used to develop models based on different machine learning classifiers. A combined model was developed combining radiomics features with clinical characteristics and a nomogram was depicted. The performance of the models was assessed by area under the receiver operating characteristic curve (AUC), calibration curve and decision curve.

RESULTS

Radiomics model based on random forest showed best performance in discriminating FTC and FTA, with AUCs 0.880 (95% confidence interval [CI]: 0.8290-0.9308), 0.871 (95% CI: 0.7690-0.9734), and 0.821 (95% CI: 0.7036-0.9389) in training, validation, and test cohort, respectively. The combined model presented better efficacy comparing with clinical model and radiomics model, with AUCs 0.883 (95% CI: 0.8359-0.9295), 0.874 (95% CI: 0.7873-0.9615), and 0.876 (0.7809-0.9714) in training, validation, and test cohort, respectively. The calibration curves suggested good consistency and decision curves showed the highest overall clinical benefit for the combined model.

CONCLUSIONS

Ultrasound radiomics model based on random forest is feasible to differentiate FTC and FTA, and the combined model is an intuitively noninvasive tool for FTC and FTA preoperative identification.

Management of Giant Thyroid Tumors in Patients with Multiple Comorbidities in a Tertiary Head and Neck Surgery Center

Background/Objectives: The thyroid gland can represent the seat of development for giant tumors exceeding 10 cm in diameter. A retrospective analysis on 21 cases of giant thyroid tumors with comorbidities, operated in the ENT Department of the Bucharest University Emergency Hospital has been conducted. Methods: Giant benign tumors accounted for 28.57% of the cases studied and reached gigantic volumes in an average time interval of 3 years, with an average resection piece weight of 318 g. Malignant tumors accounted for 71.43%, with an average duration of evolution of 7 years, with an average resection piece weight of 581 g. Results: Dysphagia was present in all patients, dyspnea in 47.61% and dysphonia in 38.09% of cases. Total thyroidectomy is the gold standard in giant thyroid tumors, associated with radical neck dissection, extended to groups VI and VII in malignant tumors. In 10 of 11 cases of giant malignant thyroid tumors (90.90%), without anaplastic thyroid carcinoma, the survival at 5 years after multimodal oncologic treatment was favorable. Anticoagulant treatment increased the risk of postoperative reversible recurrent laryngeal nerve lesion. Conclusions: The management of giant thyroid tumors in patients with multiple comorbidities needs a multidisciplinary team including endocrinologist, radiologist, anesthesiologist, pathologist, ENT surgeon, thoracic surgeon, oncologist and radiotherapist.

Meta-analysis of the effect and clinical significance of Delphian lymph node metastasis in papillary thyroid cancer

Objective

To investigate the effect and clinical significance of Delphian lymph nodes (DLN) on the factors influencing papillary thyroid cancer (PTC) to provide individualized guidance for the surgical treatment of thyroid cancer.

Methods

Relevant studies from PubMed, Web of Science, the Cochrane Library, Embase, and China National Knowledge Infrastructure databases were searched until February 13, 2023. Stringent selection parameters were used to obtain included data and homogeneous articles. Analyses were performed using Revman 5.4 and SPSS software. A P-value of < 0.05 was considered statistically significant.

Results

Five studies were finally included in this study. The results revealed a higher risk of DLN metastasis (DLNM) in patients with tumor size >1cm, multifocality, and extrathyroidal extension (ETE) of the thyroid. The risk of central lymph node metastasis (CLNM) was 11.25 times higher in DLN-positive patients with PTC than in DLN-negative (OR = 11.25, 95% CI: 8.64-14.64, P < 0.05) patients. The risk of LLNM was 5.57 times higher in DLN-positive patients with PTC than in DLN-negative (OR = 5.57, 95% CI: 4.57-6.78, P < 0.001) patients. The risk of postoperative recurrence in DLN-positive patients with PTC was 3.49 times higher (OR = 3.49, 95% CI: 1.91-6.38, P < 0.001) than in DLN-negative patients with PTC.

Conclusion

Patients with tumor size >1 cm in diameter, multifocality, and ETE have an increased risk for DLN development. DLN-positive patients with central and lateral cervical lymph node metastasis and postoperative recurrence are at higher risk than DLN-negative patients.

Propensity score matching analysis of adjuvant external-beam radiotherapy for the treatment of papillary thyroid carcinoma with other organ invasions

PURPOSE

The role of adjuvant external-beam radiotherapy (EBRT) in the treatment of locally advanced papillary thyroid carcinoma (PTC) remains controversial due to the lack of prospective data and the conflicting retrospective data. This study aimed to determine the benefits of adjuvant EBRT in patients with PTC and other organ invasions using propensity score matching to reduce the heterogeneity of the patient population.

METHODS

Data from patients with PTC with other organ invasions but no distant metastases who underwent surgery and adjuvant radioactive iodine (RAI) alone (Non-EBRT group) or adjuvant EBRT plus RAI (EBRT group) were retrospectively reviewed. Propensity matching was used to reduce heterogeneity. Survival outcomes and toxicities associated with EBRT were evaluated.

RESULTS

Between January 2005 and December 2019, 102 patients in the Non-EBRT group and 26 patients in the EBRT group were evaluated. In the 48 propensity score-matched patients, no significant differences in baseline characteristics between the Non-EBRT and EBRT groups were detected. The locoregional recurrence-free survival (LRRFS) and recurrence-free survival (RFS) rates were significantly higher in the EBRT group compared with the rates in the Non-EBRT group (5y-LRRFS: 100% vs. 74%, p = 0.003, 5y-RFS: 91% vs. 74%, p = 0.035). EBRT was well-tolerated, with no grade ≥ 3 toxicity, and all patients completed the therapy as planned.

CONCLUSION

Adjuvant EBRT plus RAI exhibited acceptable toxicity and improved LRRFS and RFS in patients with PTC with other organ invasions compared with RAI alone.

Effect of postoperative radiotherapy for patients with differentiated thyroid cancer

OBJECTIVE

We evaluated the efficacy and safety of postoperative radiotherapy (PORT) for differentiated thyroid cancer (DTC) with high risk features.

MATERIALS AND METHODS

This retrospective study analyzed 187 patients treated for DTC from 1985 to 2019. DTC referred to nonanaplastic thyroid cancer originating from follicular cells. PORT was defined as the administration of external beam radiation to the thyroid and regional lymph nodes following surgery for initially diagnosed DTC. The patients were included in the analysis if they received PORT or exhibited any of the following features: (a) pT4 or pN1b according to the 8th American Joint Committee on Cancer, (b) poorly differentiated thyroid cancer (PDTC), or (c) unfavourable variants such as anaplastic foci and etc. After 1:1 propensity matching, a total of 108 patients were analyzed according to PORT receipt. The median follow-up duration of the matched group was 10.4 years.

RESULTS

After matching, most of the variables became balanced, but the PORT group still had more PDTC and DTC with anaplastic foci. Radioactive iodine (RAI) was less frequently administered in the PORT group. PORT yielded a significantly higher 5-year locoregional recurrence free survival (LRFS) than the No PORT group (5-year LRFS 86.1% vs. 72.7%, p = 0.022), but the 10-year cancer specific survival (CSS) was similar between them (97.8% vs. 85.9%, p = 0.122). The multivariable analysis indicated that PORT was a favourable prognostic factor (Hazard ratio 0.3, 95% Confidence interval 0.1-0.8, p = 0.02) for LRFS, but not for CSS. Among 133 patients without PORT for initial disease, 39 of them received salvage surgery followed by salvage PORT. No severe toxicity after PORT was reported.

CONCLUSION

PORT reduced locoregional recurrence in DTC patients without severe toxicity. PORT can be an effective and safe treatment to improve locoregional control in DTC with high risk features. However, further study is warranted to identify those who can benefit from PORT.

Re-do Operation Using a Robotic System due to Locoregional Recurrence after Initial Thyroidectomy for Thyroid Cancer

Locoregional recurrent thyroid cancer is commonly treated with re-do operation. This study aimed to investigate the feasibility of using robotic system for re-do operation in locoregional recurrent thyroid cancer. Sixty-five patients who underwent re-do robotic operation using trans-axillary approach for locoregional recurrent thyroid cancer from October 2007 to April 2021 at Yonsei University Hospital were analyzed. Completion total thyroidectomy (CTT) was performed in 26 cases, CTT and modified radical neck node dissection (mRND) in 16, and mRND in 23. Most of the re-do robotic operations were performed at site of previous incision. All patients were diagnosed with papillary thyroid carcinoma (PTC). CTT with central compartment neck dissection (CCND) took 117.6 ± 26.3 min, CTT with mRND 255.6 ± 38.6 min, and mRND, 211.7 ± 52.9 min. Transient hypocalcemia occurred in 17 (26.2%) patients and permanent hypocalcemia occurred in 3 (4.6%). There was one case of recurrent laryngeal nerve(RLN) injury. One patient was diagnosed with structural recurrence after re-do robotic operation. Median follow-up duration was 50.7 ± 37.1 months. Re-do robotic operation can be an alternative for patients who are diagnosed with locoregional recurrent thyroid cancer after thyroidectomy, with no increase in morbidity, similar oncologic outcomes, and superior cosmetic satisfaction.

Salvage surgery for cervical radioiodine refractory 18F-FDG-PET positive recurrence of papillary thyroid cancer

PURPOSE

Five percent of patients with differentiated thyroid cancer are diagnosed with radioiodine refractory relapse in the course of the disease. For isolated or oligometastatic cervical recurrence, resection or another local treatment is recommended. In this study, the impact of surgical treatment of cervical radioiodine refractory 18F-FDG-PET positive relapse of papillary thyroid cancer (PTC) was evaluated.

METHODS

Patients receiving radioiodine therapy between 2005 and 2015 at the University Hospital of Cologne, Germany, for PTC were screened. The subgroup of patients undergoing surgery during the course of disease after recommendation by a multidisciplinary endocrine team for cervical radioiodine refractory 18F-FDG-PET positive recurrence was identified. Demographics, clinic-pathologic characteristics, oncologic treatment, and outcome were analyzed.

RESULTS

Thirty (3%) of 969 patients with PTC treated with radioiodine therapy at our institution underwent surgery for radioiodine refractory 18F-FDG-PET positive cervical recurrence during the course of the disease. In eight (26.6%) patients, more than one operation was performed. Sixteen (53%) patients received external beam radiation therapy (EBRT) after surgery. Follow-up was on average, 79.2 ± 61.6 months after the last surgical treatment. Biochemical and radiological cure was seen in 12 (40%) patients. Remission was significantly more frequent in younger patients (P = 0.0001) with lymph node rather than soft tissue tumor recurrence (P = 0.004).

CONCLUSIONS

Surgical treatment of radioiodine refractory 18F-FDG-PET positive cervical recurrence led to biochemical and radiological cure in about 40% of patients in this study. Further data are needed concerning risk stratification of potential subgroups benefitting of surgical approach and the possible role of EBRT after repetitive surgery.

External Beam Radiation Therapy in pT4 Well-Differentiated Thyroid Cancer: A Population-Based Study of 405 Patients

PURPOSE

The benefit of external beam radiation therapy (EBRT) in locally advanced, well- differentiated thyroid cancer (WDTC) is uncertain. The purpose of this study is to evaluate locoregional recurrence (LRR), progression-free survival, and cause-specific survival (CSS) of patients with pT4 well-differentiated thyroid carcinoma.

METHODS AND MATERIALS

A population-based retrospective review was conducted of consecutive patients with pT4 WDTC (per the American Joint Committee on Cancer, 8th edition, criteria) treated provincially between 1985 and 2013. The primary endpoints were cumulative incidence of LRR and CSS. To account for the competing risks of death from other causes, a Fine-Gray's test was used. A Cox-proportional hazards model was used to analyze overall survival (OS). Multivariate models and propensity matching were used to account for the effects of covariates.

RESULTS

A total of 405 patients were identified with a median follow-up time of 14.3 years for a total of 4209 person-years of follow up. The median age at the time of diagnosis was 53 years (range, 20-87). There were 211 patients (52%) who received EBRT. EBRT was associated with age ≥55 years (56% vs 35%; P < .001), airway involvement (42% vs 8%; P < .001), and R1/2 resection (81% vs 51%; P < .001). The 10-year outcomes for the non-EBRT and EBRT groups were 21.6% versus 11.4%, respectively, for LRR, 84.1% versus 93.1%, respectively, for CSS, and 85.7% versus 67.5%, respectively, for OS. On multivariate analysis, EBRT was associated with a lower rate of LRR (hazard ratio [HR]: 0.334; P < .001), but not associated with CSS (HR: 1.56; P = .142) nor OS (HR: 1.216; P = .335). After propensity score matching, the EBRT cohort had lower rates of LRR relative to the non-EBRT cohort (HR: 0.261; P = .0003), but there were no differences in CSS or OS.

CONCLUSIONS

In this large, population-based analysis of patients with pT4 WDTC, EBRT was associated with lower rates of LRR, but no difference in CSS or OS.

Prophylactic Central Lymph Node Dissection Improves Disease-Free Survival in Patients with Intermediate and High Risk Differentiated Thyroid Carcinoma: A Retrospective Analysis on 399 Patients

The role of prophylactic central lymph node dissection (pCLND) in the treatment of differentiated thyroid cancer (DTC) is controversial and still a matter of debate. The primary outcome of our study was to assess whether pCLND is effective in reducing the incidence of recurrent disease, and the secondary goal was to estimate the incidence of postoperative complications in patients who underwent pCLND and to evaluate the prognostic value of occult node metastases. In this retrospective study, we included patients with preoperative diagnosis of DTC and clinically uninvolved lymph nodes (cN0). The patients were divided into two groups, depending on the surgical approach: total thyroidectomy alone (TT group) or total thyroidectomy and pCLND (pCLND group). Three hundred and ninety-nine patients were included in this study, 320 (80.2%) in the TT group and 79 (19.8%) in the pCLND group. There were no significant differences in morbidity among the two groups. Histopathological evaluation demonstrated a similar distribution of aggressive features, especially regarding multicentricity, extrathyroidal extension, and angioinvasivity between the two groups. Occult lymph node metastases were found in 20 (25.3%) patients in the pCLND group. Prophylactic CLND was effective in improving disease-free survival in patients with intermediate and high risk of disease recurrence (p = 0.0392); occult lymph node metastases resulted as a significant negative prognostic factor (p < 0.001).