Cost-effectiveness analysis of well-differentiated thyroid carcinoma surveillance using nuclear medicine procedures

Introduction@#Well-differentiated thyroid carcinoma (WDTC) is the most common type of thyroid cancer with a notable increasing incidence worldwide. It is prevalent among Filipino descent as compared to other nationalities. Its good prognosis and high survival rate predispose patients to lifetime surveillance with incomplete response, instead of death, as outcome measure. This eventually leads to increase in cost of care, utilization, and allocation of medical resources for the survivors of the disease. Thyroglobulin immunoradiometric assay (Tg IRMA) and I-131 diagnostic whole-body scan (dWBS) are two nuclear medicine procedures that are part of WDTC surveillance. Due to their varied availability in Asia-Pacific, most clinicians measure thyroglobulin (Tg) alone due to perceived cost-effectiveness. @*Objective@#This study aims to analyze the cost-effectiveness of two nuclear medicine procedures used in WDTC surveillance, namely thyroglobulin immunoradiometric assay and I-131 diagnostic whole-body scan, in detecting incomplete response. @*Methodology@#Three clinical guidelines on WDTC management were reviewed to identify frequency, total number and expenditure for surveillance, namely from the University of the Philippines-Philippine General Hospital in 2008 (PGH 2008), American Thyroid Association in 2015 (ATA 2015), and the Department of Health (DOH 2021). A Markov model was constructed to simulate a 36-month surveillance with complete and incomplete response to treatment as disease states. Parameter values like rate of incomplete response in WDTC patients, prognostic values per each surveillance test, and other relevant data were collected from literature search and established data. The cost of surveillance was based on the rates offered by Philippine General Hospital (PGH) Radioisotope Laboratory as of November 2022. One-way sensitivity was done to check robustness of results. @*Results@#ATA 2015 incurs the most expenses, amounting to PHP 14,600.00 to 20,450.00 ($ 254.19 – 356.04) for three years of surveillance, followed by DOH 2021 (PHP 11,700.00 – 15,600.00 or $ 203.74 – 271.65), and PGH 2008 (PHP 3,900.00 – 6,825.00 or $ 67.91 – 118.85). The thyroglobulin IRMA arm costs lower (PHP 17,784.00 or $ 309.74) than I-131 dWBS (PHP 271,875.00 or $ 4,735.13) in detecting incomplete response. I-131 dWBS should cost around PHP 570.00 (or $ 9.92) to be as cost-effective as the thyroglobulin IRMA.@*Conclusion@#This study has identified that thyroglobulin IRMA is more cost-effective than I-131 diagnostic whole-body scan in detecting incomplete response in WDTC patients. This supports the perceived cost-effectiveness of thyroglobulin measurement in surveillance, even without diagnostic whole body-scans. This study also identified that the new DOH 2021 guidelines will incur lesser expenditure in using nuclear medicine procedures for surveillance as compared to ATA 2015 guidelines. Local clinicians may also find it easier to follow as it is more suitable to the Philippine setting.

Analysis of BRAF V600E mutation in bilateral well-differentiated thyroid carcinoma / 临床与实验病理学杂志

Purpose To investigate the correlation between BRAF V600E mutation and clinicopathologic parameters in bilateral welldifferentiated thyroid carcinoma.Method Collected 80 patients with papillary thyoid carcinoma (PTC) (67 patients with classical type,8 patients with follicular variant,3 patients with oncocytic variant,2 patients with tall cell variant),5 patients with follicular carcinoma and 30 normal tissues near the tumor,BRAF V600E mutation was detected via polymerase chain reaction.Result The presence of BRAF V600E mutation was found in 52 patients with PTC (65.0％),the mutation was not in the 5 patients with ollicular carcinoma as well as in the 30 normal tissues near the tumor.The BRAF V600E mutation was positively correlated with age,capsule invasion,lymph node metastasis,tumor clinical stage.In the histological variant of PTC,the BRAF V600E mutation rate of classical type and tall cell variant is very high (70.1％,100.0％),but the BRAF V600E mutation rate of follicular variant is very low (33.3％).Conclusion The BRAF V600E mutation rates are different in different age groups.The BRAF V600E mutation was positively correlated with capsule invasion,lymph node metastasis,tumor clinical stage.The BRAF V600E mutation rate of classical type and tall cell variant is very higher than follicular variant.

Results of Radioactive Iodine (131I) Therapy in Well Differentiated Thyroid Carcinoma: A Retrospective Study from the Tygerberg Hospital.

Introduction: Well Differentiated thyroid carcinoma (WDTC) represents 80% of all thyroid malignant tumours, with good prognosis and a survival rate higher than 90% at 20 yrs. Total or subtotal thyroidectomy is the treatment of choice, with radioactive iodine (RAI) therapy reserved for adjuvant setting/ablation and/or as a curative treatment modality in patients with local recurrence and/or distant metastases. This retrospective study aimed to investigate the treatment outcome, survival rate and prognostic factors in our institution over the past half-decade. Methods: A retrospective study was conducted of 33 patients with WDTC. Data were collected from 1stJanuary 2007 to 31st December 2012 and included: Age at diagnosis, sex, histology, TNM stage, treatment received, indication for 131I therapy, doses of 131I, complication of treatment, follow-up diagnostic scan 123I / Thyroglobulin, time of recurrence since surgery and cause of death. Prognostic factors were analysed using chi-square test and crude mortality rate was used. Results: Papillary subtype is the most common type of WDTC (63.6%); mean age at diagnosis is 50 years and female to male ratio is cosmopolitan at 3.1:1 with female preponderance. RAI therapy after thyroidectomy (total or subtotal) offers complete remission in 26/33 (78.8%) and the overall mortality rate was 3/33 (9.1%) p=0.023. Conclusion: RAI therapy is safe and effective in management of patients with WDTC. The initial surgical approach is the cornerstone in the subsequent outcome of RAI therapy with very poor outcome registered in unresectable thyroid tumour and in patients with multiple organ metastases.

A Closer Look at Papillary Thyroid Carcinoma

Recent surge of thyroid cancer, especially papillary thyroid carcinoma (PTC), ignited a debate on over-diagnosis of cancer. Such increase in incidence is a worldwide phenomenon, but it has been the most prominent in Korea. Although increased detection might have played a major role, some evidences suggest that true increase in incidence have also contributed to such phenomenon. PTC is a very common disease being the most common cancer in human. As the mortality due to PTC is relatively low, understanding pathophysiology of the disease and risk prediction in individual patient have particular importance for optimal management, but little has been known. I suggest a reason for such a commonality of PTC, and would like to describe my view on some aspects of PTC including unresolved issue on management based on our recent observations.

N Stage: Controversies and Recent Issues / 대한갑상선학회지

The current TNM staging including N staging has been suggested as a gold standard for the appropriate therapy in the well differentiated thyroid cancer patients. N staging was established based on histopathologic findings, however, the newly suggested prognostic factors for the revision of N staging include some clinicopathologic factors, such as clinical metastasis (macrometastasis), large node metastasis (> or =3 cm), extranodal extension and the number of metastatic node. Recently, American Thyroid Association reported the possibility that the low-risk group patients would be overestimated as high-risk group patients that leads to the overtreatment, the following unnecessary complication and the economic cost. The preexisting N1a/N1b classification by anatomical location of metastatic node still remains as a strong prognostic factor; however, many evidences indicated that the clinicopathologic factors described above should be considered in the risk stratification in the near future. Thus, it needs to be stressed that the four factors of micrometastasis, large node metastasis (> or =3 cm), gross or microscopic extranodal extension and multiple metastatic node (>5 cm) have been established as negative or positive prognostic factors and should be noted in clinical practice.

Treatment of Mediastinal Lymph Node Metastases in Differentiated Thyroid Carcinoma

PURPOSE: In case of well-differentiated thyroid carcinoma, a mediastinal lymph node metastasis is extremely rare, but can be life threatening due to its proximity to the vital organs. The consequence of radical extirpation must be balanced against the issues of tumor control, survival outcomes, functional morbidity, and the sequelae of an excessive surgical resection. The aim of this study was to clarify the clinicopathological characteristics, treatment and outcomes of patients with mediastinal lymph node metastasis in differentiated thyroid carcinoma. METHODS: Nineteen consecutive differentiated thyroid carcinoma patients with a mediastinal lymph node metastasis between June 1998 and Feb. 2004 were included in this study. All the patients underwent a trans-sternal mediastinal lymph node dissection in addition to thyroid cancer surgery. The median follow-up was 40.7 months (range, 18~97). RESULTS: The mean age was 49 years (range 31~72 years) with a male-to-female ratio of 8: 11. The surgical treatment included 11 cases of an upper mediastinal lymph nodes dissection via a partial sternotomy and 7 cases of a whole mediastinal lymph nodes dissection via a total longitudinal sternotomy. In 6 cases, the combined resection of the involved organ was added. Major postoperative complications occurred in two patients, one with leakage from a tracheoesophageal fistula and the other with a pulmonary embolism. During the follow-up period, local recurrences in the lateral cervical nodes were observed in 5 cases. The 5 year overall survival and 5 year disease-free survival were 90.5% and 63.6%, respectively. There was only one surgical mortality. CONCLUSION: These results suggest that the prognosis for mediastinal lymph node metastasis in differentiated thyroid carcinoma can be improved by an aggressive mediastinal node dissection and the appropriate thyroid cancer surgery.

The Optimal Timing for Surgery in Well-differentiated Thyroid Carcinoma Detected during Pregnancy

PURPOSE: The optimal timing of a surgery for well-differentiated thyroid carcinoma detected during pregnancy remains controversial. This study was performed to determine the optimal timing of surgery for a well-differentiated thyroid carcinoma detected during pregnancy. METHODS: Betwwen July 1991 and June 2004, 20 cases diagnosed with a well-differentiated thyroid carcinoma during pregnancy were retrospectively analyzed. All 20 patients had undergone surgery. The patients were divided into three groups according to the timing of their surgery. Group I (n=9) had a thyroidectomy after delivery, group II (n=6) had a thyroidectomy during the second trimester, and group III (n=5) had a thyroidectomy after an abortion. Group III was excluded from the study as our particularly interest was in determining the optimal timing of surgery during pregnancy. RESULTS: No significant differences were noted between groups I and II with regard to age, tumor size, TNM stage and the timing of diagnosis. There were no TNM stage changes in group I, although a slight increase in tumor size during pregnancy was noted. There were no significant differences in the surgical outcomes between groups I and II with regard to types of operation, operation times, perioperative complications, length of hospital stays and treatment outcomes. CONCLUSION: The treatment of a well-differentiated thyroid carcinoma detected during pregnancy can be delayed until after delivery in most patients.