Thyroid Remnant In Patients Research Articles

Efficiance of radioiodine remnant ablation in cases of locally differentiated thyroid cancer

On the territory of Russia has increased the of thyroid cancer after Chernobyl NPP incidence at 1986, and currently accounts for up to 14,000 newly identified cases. Postoperative radioiodine (RAI) remnant ablation is the second stage of combine treatment of differentiated thyroid cancer, except for the prevalence of pT1N0M0, with minimal level of TG and AT-TG, according to international guidelines. In the past 20 years a significant number of published practice guidelines for the treatment of this disease. However, the discussion is the amount of medication for administration activity (GBq) 131I, is required for successful ablation of thyroid remnants. The study analyzed 353 clinical cases after radical surgical treatment for DTC. In our study, the effectiveness of radioiodablation was compared with certain indicators of specific therapeutic activity 131I (MBq/kg), in groups of patients with different levels of TSH stimulation (less than 30 mME/ml, and more than 30 mME/ml). We evaluated the absorbed dose in the thyroid remnant in patients with residual thyroid tissue volume determined by US when administering 131I empirical therapeutic activity. The control of the WBS with 131I was carried out in 6 months. The average eղciency RAI was 85.5 %, there were no significant differences in the TSH stimulation groups of more than 30 mME/ml and 4-30 mME/ml (p > 0.05). If the thyroid remnant is not detected by US, the effective range of 131I specific therapeutic activity is 30-40 MBq/ kg against a background of TTG stimulation greater than 4 ՏME/ml and strict adherence to a 14-day low iodine diet. Direct radiometry followed by neck scintigraphy (1200 kBq 131I) and calculation of therapeutic activity is recommended when determining thyroid remnant by US to plan for TAD = 300 Gy and reduce the risk of radiation sialoadenitis. At the time of RAI, 3.9 % of patients had previously undetectable X-rays lung metastases with stimulated TG levels greater than 124 ng/mL after surgical treatment with SPECT/CT.

Radioiodine Ablation of Thyroid Remnants in Patients with Graves' Orbitopathy.

Our purpose was to assess response after ablation of thyroid remnants (ATR) with radioactive iodine therapy in patients with unstable Graves' orbitopathy (GO) after subtotal thyroidectomy. Methods: Thirty patients with mild (n = 4, 13%), moderate-to-severe (n = 25, 83%), or very severe GO (n = 1, 3%) were analyzed in this retrospective study. The primary endpoint was the improvement of GO-related symptoms as assessed by clinical activity scores, NOSPECS, and soft-tissue inflammation scores at 3 and 12 mo after ATR. Ablation success was defined by a decrease in 99mTc uptake on thyroid scintigraphy, remnant volume, and thyrotropin receptor antibody levels at 3 mo after ATR. Results: Twelve months after ATR, clinical activity scores, NOSPECS, and soft-tissue inflammation scores showed a significant decrease from 3.4 to 1.3 (P < 0.0001), 5.9 to 4.9 (P = 0.007), and 4.7 to 2.1 (P = 0.0001), respectively. The GO was inactive in 27 of the 30 (90%) patients after 3 mo and in 29 (97%) after 12 mo. No new activation of GO occurred. Remnant volume (1.4 vs. 0.4 cm3, P = <0.0001), mean thyrotropin receptor antibody level titer (19.02 vs. 13.37 IU/L, P < 0.0001), and 99mTc uptake (0.5% vs. 0.1%; n = 12; P = 0.04) decreased significantly until 3 mo after ATR. Discussion: Radioactive iodine therapy after thyroidectomy can successfully ablate residual thyroid remnants, leading to an improvement in GO, a reduction in inflammatory activity, and stabilization of thyroid function. Thus, scintigraphy should be considered for patients with unstable GO after thyroidectomy to rule out thyroid remnants.

Correlation analysis of I-131 SPECT/CT uptake parameters with the success ablation treatment of thyroid remnant in patients with low-intermediate-risk differentiated thyroid cancer.

To predict the successful outcome of radioactive iodine-131 (I-131) ablation treatment for differentiated thyroid cancer (DTC) patients using quantitative parameters from therapeutic I-131 SPECT/CT. This retrospective study enrolled 145 DTC patients (41 males and 104 females) who had radioactive iodine-131 (I-131) (RAI) ablation therapy following thyroidectomy surgery from July 2020 to May 2021. The median age was 47 years (24-65 years). All the patients underwent therapeutic I-131 thyroid SPECT/CT scan after RAI ablation. The I-131 uptake quantitative parameters SUV max , SUV mean %ID and ∆Tg (defined as the Tg level before RAI ablation minus the Tg level after six months) were assessem. Successful ablation treatment was defined as the level of TSH-stimulated Tg≤1 ng/mL and the disappearance of the thyroid bed on a whole-body I-131 scan six months or later after ablation treatment. The quantitative parameters from therapeutic I-131 SPECT/CT of the successful ablation (n=130) group with SUV max 7.74 (3.84, 18.78) g/ml, SUV mean 4.02 (2.11, 6.39) g/ml and %ID 2.21% (0.67%, 7.30%) were significantly higher than those of the unsuccessful (n=15) group 0.75 (0.53, 1.28) g/ml, 0.44 (0.29, 0.79) g/ml and 0.16% (0.06%, 1.48%) (Z=-5.87, -5.71 and -4.99, all P < 0.001). SUV max , SUV mean and %ID were positively correlated with ΔTg (all P < 0.001). Receiver operating characteristics curve analysis showed that %ID performed better predict value than either SUV max (AUC=0.914, and 0.874, P=0.009) or SUV mean (AUC= 0.863 P=0.002). SUV max , SUV mean and%ID (OR =1.50, 2.85 and 1.01 all P < 0.001) were all independent predictors of successful RAI ablation. The quantitative parameters of therapeutic I-131 SPECT/CT were related to the efficacy of ablation treatment, and %ID could predict the successful outcome of ablation treatment for DTC patients.

Postablative 131I SPECT/CT Is Much More Sensitive Than Cervical Ultrasonography for the Detection of Thyroid Remnants in Patients After Total Thyroidectomy for Differentiated Thyroid Cancer

Evaluation of utility of cervical ultrasound (US) for detection of thyroid remnants (ThR) in patients after thyroidectomy for differentiated thyroid cancer. Included were 154 consecutive patients (17-89 years, 123 female and 31 male patients), without known cancer residues or cervical lymph nodes metastases, admitted for ThR ablation with I, 14 to 20 weeks after surgery. Neck uptake of I (Tup) and thyroglobulin were determined, and location and volume of ThR detected by cervical US were recorded. On days 3 to 4 after ablation (1.7-4.6GBq, 46-124.3 mCi I), neck SPECT/CT was performed, and I uptake foci were assigned to one of the regions as described below. The anterior neck was divided into 2 compartments: superior and inferior to lower margin of thyroid cartilage, and each compartment was subdivided into middle and lateral regions (in SPECT/CT, posterolateral and anterolateral regions were also marked out). I uptake sites and ThR detected by US, if congruent with SPECT/CT, were counted and analyzed. In total, 341 I uptake foci were found in 150 patients (97.4%) by SPECT/CT and 213 corresponding ThR in 118 patients (76.6%) by US. Ultrasound detected 30% to 46% of I uptake foci in superior lateral regions, 49% in pyramidal lobe/thyroglossal duct area (both P < 0.05), 74% to 77% in inferior lateral regions, and 22% in isthmus (both P > 0.05). Correlation between ThR volume and Tup was strong (r = 0.79), and that between ThR volume and thyroglobulin was weak (r = 0.24). Ultrasound is less sensitive than I posttherapy scans for ThR detection in patients after thyroidectomy, especially for remnants located above the lower margin of thyroid cartilage.

PROBABILITY OF CANCER DETECTION DURING REPEATED OPERATIONS IN PATIENTS WITH BENIGN THYROID DISEASES

Introduction. Suspected malignant growth in patients with recurrent goiter is one of the main causes of repeated operations. Focuses of carcinoma can be detected in patients operated on for multinodular goiter with compression of the organs of the neck, recurrent diffuse toxic goiter. Objective of investigation is to assess the risk of a malignant lesion of the thyroid remnant in patients with recurrent goiter, to justify the surgical tactics in this group of patients. Material and methods. In the St. Petersburg Center of Endocrine Surgery and Oncology 28138 patients with various thyroid diseases were operated on for the period from 1973 till 2016. Results. In a retrospective analysis of the group consisting of 1106 patients with recurrent goiter, a new thyroid disease was detected in 156 (14.1%) cases. Thyroid cancer in thyroid remnant was detected in 57 (36.5%) cases or 5.2% of all the patients with recurrent goiter. The work describes the risk of malignant lesion of the thyroid remnant in patients with recurrent goiter and surgical tactics in this group of patients. Conclusion. Cancer of the thyroid gland, as a new disease of the thyroid remnant, in patients previously operated on for benign thyroid pathology, is found in 5.2% of observations. The possibilities of fine-needle aspiration biopsy in this group are reduced. Active surgical tactics in cases of multinodular transformation of the thyroid remnant is justified. The operation of choice is reresection up to thyroidectomy. Careful intraoperative study of removed tissue and close cooperation with the morphological service helps to reduce the number of diagnostic and tactical errors in patients with both recurrent and ordinary multi-node goiter.

Diagnostic 123I Whole Body Scan Prior to Ablation of Thyroid Remnant in Patients With Papillary Thyroid Cancer: Implications for Clinical Management.

The use of I whole body scintigraphy (WBS) before I radioiodine ablation (RIA) of the post-surgical thyroid remnant in patients with papillary thyroid cancer (PTC) remains debated. The American Thyroid Association's guidelines state that WBS may be useful before RIA (rating C-expert opinion). Some institutions do not use I WBS before RIA in their routine clinical protocol. We were therefore prompted to evaluate the impact of I WBS prior to ablation of thyroid remnant in patients with PTC. We reviewed data from 152 consecutive patients with PTC who had total thyroidectomy and were referred for RIA between August 2007 and February 2009 at our institution. The group included 107 women and 45 men, 13-82 years old (mean ± SD: 45.5 ± 18.3). Three endocrinologists blinded to the results of the I WBS reviewed patients' data including sex, age, pathology, thyroglobulin (Tg) level, anti-Tg antibodies, thyroid stimulating hormone (TSH) level and ultrasound results. Each endocrinologist then returned a form with the recommended I dose for each participant, according to the following rules: 50-75 mCi (remnant ablation), 75-125 mCi (lymph nodes metastases), 150 mCi (lung metastases), and 200 mCi (bone metastases). We compared their recommended doses with the actual I doses prescribed after the pre-therapy I WBS. All three endocrinologists recommended the same dose in 98.7% of the cases. The dose prescribed by the endocrinologists matched the dose administered after analyzing the I WBS in 77 patients (51%). However, for 46 patients (30%) the endocrinologists would have given a lower dose, for 18 patients (12%) a higher dose than that administered based on the results of the I WBS, while 11 patients (7%) would have been treated unnecessarily (5/11 had no I uptake and 6/11 had I uptake in the breasts). Our study suggests a significant role of the pre-therapy I WBS in PTC patients referred for I ablation post-thyroidectomy. The actual I dose that was administered based on the I WBS differed from the dose recommended in the absence of the I WBS in 49% of the cases.

Use of low-dose radioiodine ablation for Graves' orbitopathy: results of a pilot, perspective study in a small series of patients.

Elimination of thyroid antigens by total thyroid ablation (TTA), namely, thyroidectomy followed by radioiodine, may be beneficial for Graves' Orbitopathy (GO). TTA is usually performed with a 131I dose of 30mCi. In Italy, this dose must be followed by a 24-h protected hospitalization, with increase in the waiting lists. In contrast, a 15mCi dose can be given without hospitalization and with lower costs. Here, we investigated whether a lower dose of radioiodine can be used to ablate thyroid remnants in patients with GO, after thyroidectomy. The study was performed in two small groups of consecutive thyroidectomized patients (six patients per group) with Graves' hyperthyroidism and GO. Patients underwent ablation with either 15 or 30mCi of 131I following treatment with recombinant human TSH (rhTSH). The primary outcome was rhTSH-stimulated serum thyroglobulin (Tg) at 6months. The secondary outcome was baseline Tg at 6months. Baseline Tg and rhTSH-stimulated Tg after at 6months did not differ between two groups, suggesting a similar extent of ablation. rhTSH-stimulated Tg was reduced significantly compared with rhTSH-stimulated Tg at ablation in both groups. GO outcome following treatment with intravenous glucocorticoids did not differ between the two groups. Our findings may provide a preliminary basis for the use of a 15mCi dose of radioiodine upon rhTSH stimulation in thyroidectomized patients with Graves' hyperthyroidism and GO.

Serum thyroglobulin level after radioiodine therapy (Day 3) to predict successful ablation of thyroid remnant in postoperative thyroid cancer.

The utility of serum thyroglobulin (Tg) level, 3 days after radioactive iodine (RAI) therapy, was assessed as a means of predicting successful ablation of thyroid remnant in patients with postoperative thyroid cancer. A total of 152 patients with thyroid cancer (mean age = 44.9 ± 13.7 year) undergoing RAI therapy after total thyroidectomy were included. Levels of TSH-stimulated Tg prior to ablation (stimTg) and serum Tg sampled immediately after RAI therapy (Day 3) were measured (immTg). ImmTg samples were collected during patient hospital visits for scheduled follow-up of radioiodine scans. Successful ablation was determined by the second time stimulated Tg levels (≤1 ng/ml) and negative radioiodine uptake at thyroid bed after 6.1 ± 1.1 months of RAI therapy. Univariate and multivariate analyses were done for immTg, stimTg, change in Tg levels (deltaTg: immTg - stimTg), immTg:stimTg ratio (ratioTg), and other potential clinical and pathologic markers of successful ablation. Of selected laboratory variables, ratioTg was a significant predictor of successful ablation. StimTg, tumor diameter, metastatic lymph node (LN) numbers, lymphatic invasion were possible clinical markers of successful ablation by univariate analysis. By multivariate analysis, ratioTg (odds ratio = 7.851), stimTg (odds ratio = 16.819), metastatic LN numbers (odds ratio with stimTg = 6.732) proved significant results. Furthermore, combining high ratioTg and low stimTg provided added predictive value. High ratioTg (reflecting extensive release of Tg to the blood after RAI therapy) and low stimTg (reflecting small remnant thyroid tissue) constitute the indices of successful ablation after RAI therapy. Immediate Tg level could give an useful information on RAI ablation of postoperative thyroid remnant.

Comparison of 800 and 3700 MBq iodine-131 for the postoperative ablation of thyroid remnant in patients with low-risk differentiated thyroid cancer

The initial treatment of differentiated thyroid cancer is thyroidectomy, followed by remnant ablation with iodine-131 (I-131) in some patients. However, controversy exists concerning the appropriate radioiodine dose. The aim of the study is to compare the success rate of low and high activities of I-131 for postoperative remnant ablation. A total of 108 nonmetastatic low-risk patients (mean age: 46, 85% women) with papillary and follicular carcinoma had I-131 ablation for the postoperative thyroid remnant. Fifty-three patients received a low dose (L) (800 MBq) and 55 patients received a high dose (H) (3700 MBq) of I-131. After total thyroidectomy, thyroid bed I-131 uptake (RAIU) and neck ultrasonography (USG) were performed to determine the remnant volume and the iodine avidity, which were used to calculate the dose delivered to the remnant tissue. The success rate of I-131 ablation was assessed with four different criteria based on serum thyroglobulin (Tg) and USG with and without the utilization of I-131 diagnostic whole-body scintigraphy (DxWBS). Ablation was considered to be successful if patients fulfilled all of the following criteria. (a) Strict criteria based on three tests: (i) USG negative, (ii) no tracer uptake or less than twice the background activity in the thyroid bed on DxWBS and/or up to 0.2% RAIU, and (iii) Tg < 0.2 ng/ml; (b) lax criteria based on three tests: (i) USG negative, (ii) no tracer uptake or less than twice the background activity in the thyroid bed on DxWBS and/or ≤ 0.2% RAIU, and (iii) Tg < 2 ng/ml; (c) strict criteria based on two tests: (i) USG negative and (ii) Tg < 0.2 ng/ml; (d) lax criteria based on two test: (i) USG negative and (ii) Tg < 2 ng/ml. When three tests were used to define successful ablation, in group L, 32 out of 53 (60%) and 43 out of 53 (81%) patients were successfully treated versus 35 out of 55 (64%) and 42 out of 55 (76%) for group H on the basis of strict and lax criteria, respectively (P=NS). The differences were not statistically significant between the two groups when only two tests were used to define ablation success (62 vs. 69% with strict and 89 vs. 87% with lax criteria, respectively). Our findings suggest that remnant thyroid tissue in patients with low-risk, well-differentiated thyroid cancer after total thyroidectomy can be ablated with 800 MBq of I-131. The success rate is not different from that obtained with 3700 MBq I-131.

Clinical Outcome of Low-risk Differentiated Thyroid Cancer Patients after Radioiodine Remnant Ablation and Recombinant Human Thyroid-stimulating Hormone Preparation

AimRecombinant human thyroid-stimulating hormone (rhTSH) has been approved in Europe as a preparation tool for radioiodine ablation of post-surgical thyroid remnants in patients with low-risk differentiated thyroid cancer (DTC). Published studies report that, both thyroid hormone withdrawal and rhTSH preparation result in similar rates of successful remnant ablation, but few studies have determined the effectiveness of rhTSH preparation on disease recurrence. We sought to determine the clinical outcome, considering both ablation success and disease recurrence, of low-risk DTC patients who underwent 131I ablation. Materials and methodsThis retrospective study describes the clinical outcome of 100 patients treated with 131I remnant ablation after preparation with rhTSH. After ablation, patients were classified as in complete remission, as having no evidence of persistent disease, or as having clinical recurrence on the basis of a subsequent diagnostic whole body scan with 131I, stimulated thyroglobulin and cross-sectional imaging studies. ResultsOverall assessment of ablation success was verified and obtained in 75% of patients (75/100). Considering only patients who underwent a diagnostic whole body scan and stimulated thyroglobulin without interfering anti-thyroglobulin antibody, complete ablation was obtained in 96% of patients (75/78). After a follow-up of about 4 years, 78 patients are in complete remission: 75 with initial ablation success and three who achieved a complete remission during subsequent follow-up. Among the remaining 22 patients, 21 have no clinical evidence of disease (NCED), indicating the inability to verify the complete remission or to detect residual disease, as in patients with positive thyroglobulin antibody, whereas one has persistent disease demonstrated only by stimulated thyroglobulin. No recurrences were observed. Of four patients initially classified as having persistent disease, one obtained a complete remission and two are now considered NCED. ConclusionOur data confirm the favourable outcome, with low rates of recurrence and persistent disease, of patients with low-risk DTC who underwent 131I ablation after rhTSH. Moreover, our results compare favourably with those reported in the literature in patients prepared with rhTSH, but also in patients prepared with hormone withdrawal.

Effects of I-131 therapy on gonads and pregnancy outcome in patients with thyroid cancer

We examined the effects of I-131 therapy for thyroid cancer on female and male gonads and pregnancy outcome. After an extensive review of the published literature we concluded that ablative administration of I-131 therapy may result in transient abnormalities of ovarian and testicular function, but subsequent pregnancies are safe without any significant consequences to offspring outcome.

A Pragmatic Protocol for I-131 rhTSH-Stimulated Ablation Therapy in Patients With Renal Failure

Ablation of thyroid remnants in patients with differentiated thyroid carcinoma and renal failure can be challenging because of the altered and variable clearance rates of iodine from the blood secondary to variations in dialysis protocols, which complicate the selection of the appropriate I-131 dose. The advent of recombinant human TSH allows a simpler approach to dosimetry and ablation without rendering the patient hypothyroid. Avoidance of hypothyroidism may be an important consideration for patients who are experiencing various morbidities from conditions associated with renal failure. Three patients on dialysis, who had undergone total thyroidectomy and were euthyroid on L-thyroxine replacement, were given diagnostic doses of I-131 followed by blood and whole-body retention measurements through serial dialyses to determine individual blood clearance rates. After administration of rhTSH, each patient received an ablative dose of I-131 calculated to keep total body dose below 1 Gy. The treatments were administered without complications, and in follow-up imaging of 2 available patients, the ablations were demonstrated to be complete. Dosimetry performed on euthyroid dialysis patients permits I-131 dose selection and avoids the additional morbidity of hypothyroidism.

Iodine-Refractory Thyroid Carcinoma

The management of thyroid carcinomas commonly involves thyroidectomy, radioactive iodine to ablate any thyroid remnant in patients at high risk of recurrence, and suppressive thyroid hormone replacement. However many tumors will de-differentiate and become refractory to radioactive iodine. After progressive dedifferentiation the prognosis for these patients is poor, with no curative options available as these tumors respond poorly to currently available agents. In this review, we examine the unique biology of thyroid cancer and the various intracellular pathways which are currently the subject of intensive focus. Trials evaluating the efficacy of cytotoxic chemotherapeutic agents in iodine-refractory thyroid carcinoma and current novel therapeutic approaches will be emphasized.