Random Forest for Predicting Treatment Response to Radioiodine and Thyrotropin Suppression Therapy in Patients With Differentiated Thyroid Cancer But Without Structural Disease

BACKGROUND

We aimed to develop a machine-learning model for predicting treatment response to radioiodine (131I) therapy and thyrotropin (TSH) suppression therapy in patients with differentiated thyroid cancer (DTC) but without structural disease, based on pre-treatment information.

PATIENTS AND METHODS

Overall, 597 and 326 patients with DTC but without structural disease were randomly assigned to "training" cohorts for predicting treatment response to 131I therapy and TSH suppression therapy, respectively. Six supervised algorithms, including Logistic Regression, Support Vector Machine, Random Forest (RF), Neural Networks, Adaptive Boosting, and Gradient Boost, were used to predict effective response (ER) to 131I therapy and biochemical remission (BR) to TSH suppression therapy.

RESULTS

Stimulated and suppressed thyroglobulin (Tg) and radioiodine uptake before the current course of 131I therapy were mostly attributed to ER to 131I therapy, while thyroid remnant available on the post-therapeutic whole-body scan at the last course of 131I therapy and TSH were greatly contributed to Tg decline under TSH suppression therapy. RF showed the best performance among all models. The accuracy and area under the receiver operating characteristic curve (AUC) for segregating ER from non-ER during 131I therapy with RF were 81.3% and 0.896, respectively. The accuracy and AUC for predicting BR to TSH suppression therapy with RF were 78.7% and 0.857, respectively.

CONCLUSION

This study demonstrates that machine learning models, especially the RF algorithm are useful tools that may predict treatment response to 131I therapy and TSH suppression therapy in DTC patients without structural disease based on pre-treatment routine clinical variables and biochemical markers.

Usefulness of second 131I treatment in biochemical persistent differentiated thyroid cancer patients

Background

Second 131I treatment is commonly performed in clinical practice in patients with differentiated thyroid cancer and biochemical incomplete or indeterminate response (BiR/InR) after initial treatment.

Objective

The objective of the is study is to evaluate the clinical impact of the second 131I treatment in BiR/InR patients and analyze the predictive factors for structural incomplete response (SiR).

Patients and methods

One hundred fifty-three BiR/InR patients after initial treatment who received a second 131I treatment were included in the study. The clinical response in a short- and medium- long-term follow-up was evaluated.

Results

After the second 131I treatment (median 8 months), 11.8% patients showed excellent response (ER), 17% SiR, while BiR/InR persisted in 71.2%. Less than half (38.5%) of SiR patients had radioiodine-avid metastases. Patients who, following the second 131I treatment, experienced SiR had larger tumor size and more frequently aggressive histology and vascular invasion than those experienced BiR/InR and ER. Also, the median values of thyroglobulin on levothyroxine therapy (LT4-Tg), Tg peak after recombinant human TSH stimulation (rhTSH-Tg) and thyroglobulin antibodies (TgAb) were significantly higher in patients who developed SiR. At last evaluation (median: 9.9 years), BiR/InR persisted in 57.5%, while 26.2% and 16.3% of the patients showed ER and SiR, respectively. About half of BiR/InR patients (71/153 (46.4%)) received further treatments after the second 131I treatment.

Conclusions

Radioiodine-avid metastatic disease detected by the second 131I is an infrequent finding in patients with BiR/InR after initial treatment. However, specific pathologic and biochemical features allow to better identify those cases with higher probability of developing SiR, thus improving the clinical effectiveness of performing a second 131I treatment.

Outcomes of patients with differentiated thyroid cancer risk-stratified according to the American thyroid association and Latin American thyroid society risk of recurrence classification systems

OBJECTIVES

The aims of this study were to validate the proposed Latin American Thyroid Society (LATS) risk of recurrence stratification system and to compare the findings with those of the American Thyroid Association (ATA) risk of recurrence stratification system.

SUBJECTS AND METHODS

This study is a retrospective review of papillary thyroid cancer patients treated with total thyroidectomy and radioactive iodine at a single experienced thyroid cancer center and followed according to the LATS management guidelines. Each patient was risk-stratified using both the LATS and ATA staging systems. The primary endpoints were (i) the best response to initial therapy defined as either remission (stimulated thyroglobulin [Tg] <1 ng/mL, negative ultrasonography) or persistent disease (biochemical and/or structural), and (ii) clinical status at final follow-up defined as no evidence of disease (suppressed Tg <1 ng/mL, negative ultrasonography), biochemical persistent disease (suppressed Tg >1 ng/mL in the absence of structural disease), structural persistent disease (locoregional or distant metastases), or recurrence (biochemical or structural disease identified after a period of no evidence of disease).

RESULTS

One hundred seventy-one papillary thyroid cancer patients were included (mean age 45 ± 16 years, followed for a median of 4 years after initial treatment). Both the ATA and LATS risk stratification systems provided clinically meaningful graded estimates with regard to (i) the likelihood of achieving remission in response to initial therapy, (ii) the likelihood of having persistent structural disease in response to initial therapy and at final follow-up, (iii) the likely locations of the persistent structural disease (locoregional vs. distant metastases), (iv) the likelihood of recurrence, and (v) the likelihood of being no evidence of disease at final follow-up. The likelihood of having persistent biochemical evidence of disease was not significantly different across the staging categories.

CONCLUSIONS

Both the ATA and LATS risk of recurrence systems effectively risk-stratify patients with regard to multiple important clinical outcomes. When used in conjunction with a staging system that predicts disease-specific mortality, either of these systems can be used to guide risk-adapted individualized initial management recommendations.

A case of acromegaly and disseminated follicular thyroid carcinoma

INTRODUCTION

A particularly challenging case of concurrent acromegaly and follicular thyroid carcinoma in a patient of the Clinic of Endocrinology, UJCM in Krakow is discussed.

CASE DESCRIPTION

A 59-year-old male with post total thyroidectomy performed in 2005 and histopathologically confirmed metastases of the follicular thyroid carcinoma to the lungs was admitted to the Clinic in April 2006 for complementary ¹³¹I treatment. Acromegaly was treated in 1996 by trans-sphenoidal surgery. In December 2005 a relapse of pituitary adenoma was shown by MRI, which correlated with increased levels of hGH and IGF-1. Biochemical control of acromegaly was achieved with Sandostatin LAR. Pre-therapeutic whole-body scintigraphy (WBS) revealed numerous conjoined hot spots of ¹³¹I accumulation in both lungs and in thyroid remnants. In May and November 2006 the patient received ¹³¹I treatment. Post-therapeutic WBS in November 2006 revealed complete ablation of the thyroid remnants. Laboratory tests confirmed lowering of thyroglobulin concentration. In the years 2007, 2008, and 2009 the patient was qualified for therapy with ¹³¹I aided by rhTSH, achieving further reduction of Tg levels. Post-therapeutic WBS performed in 2009 revealed weak bilateral tracer uptake in the lung parenchyma. In 2010, chest CT revealed fibrosis in left lung segments, no infiltrative changes, and no lymph node enlargement. Patient follow-up continues at our Department.

CONCLUSIONS

Disseminated thyroid cancer in a patient with pituitary insufficiency may be successfully treated by rhTSH-supported ¹³¹I treatment.

[Benign hepatic cyst mimicking thyroid carcinoma metastasis]

INTRODUCTION

The follow-up of differentiated thyroid carcinoma (DTC) for detecting persistent or recurrent disease is based on iodine whole body scan (WBS), the evaluation of the tumor marker thyroglobulin (Tg), the anti-thyroglobulin antibody (anti-Tg) and neck ultrasonography (US). Well known false-positive causes of WBS include inflammatory processes, some non-thyroid tumors, kidney or even sebaceous cysts .

METHODS

We reported a case of false-positive WBS, after therapeutic dose of (131I) NaI.

RESULTS

We enphasize the importance of recognizing benign liver cysts mimicking DTC metastasis.

CONCLUSIONS

False-positive and negative results may occur with WBS and must be recognized to avoid mismanagement.

Four new cases of PHACES syndrome: variable phenotypic expression and endocrine features

AIM

PHACES syndrome is a neurocutaneous condition characterized by the coexistence of large facial haemangiomas and at least one feature among posterior fossa malformations, cardiac and arterial anomalies, eye defects and sternal clefting. We review and discuss the phenotypes and the endocrine aspects of PHACES syndrome, hypothesizing that endocrine anomalies, although rare, could be considered as feature of the disease.

METHODS

We described four new cases representative of the wide variable phenotype of this syndrome, commenting on the possible phenotypic expression.

RESULTS

Two children displayed endocrine anomalies, sporadically described among PHACES subjects. One of them developed a transient hyperthyreotropinemia induced by interferon alpha-2alpha treatment for a giant facial haemangioma, while the second presented with congenital hypothyroidism with an in situ thyroid gland, a trait previously unreported in the syndrome.

CONCLUSION

PHACES syndrome has a wide variable phenotypic expression and endocrine anomalies, especially hypothyroidism, may represent a trait of the syndrome and should be always investigated.

O ensaio de tiroglobulina com melhor sensibilidade funcional enquanto os pacientes tomam L-T4 substituirá a tiroglobulina estimulada pelo TSH no seguimento dos pacientes com câncer diferenciado da tiróide?

O autor apresenta evidências recentes da literatura que mostram que ensaios de tiroglobulina sérica (sTg) com maior sensibilidade funcional apresentam a mesma qualidade que a obtenção da sTg estimulada por rhTSH ou hipotiroidismo, no seguimento de pacientes com câncer diferenciado de tiróide (CDT). Desta forma, propõe modificar a prática recomendada pelas diretrizes de sociedades internacionais para o seguimento desses pacientes (desenvolvidas enquanto os ensaios disponíveis apresentavam sensibilidade de 1 ng/mL), substituindo-se a obtenção da sTg estimulada por rhTSH ou hipotiroidismo pelo acompanhamento dos pacientes na vigência da terapia com L-T4 com a medida da sTg desde que se empreguem técnicas com sensibilidade funcional da ordem de 0,1-0,2 ng/mL.

Thymoglobulin induction is safe and effective in live-donor renal transplantation: a single center experience

BACKGROUND

The relative benefit versus safety of induction therapy in live-donor renal transplant recipients is controversial. This paper presents observational data of live-donor recipients who received Thymoglobulin induction and standard maintenance immunosuppressive therapy.

METHODS

Review and analysis of clinic records and electronic databases of live-donor renal transplants that received Thymoglobulin induction from May 1996 through 2003.

RESULTS

Data analysis included 214 live-donor recipients (146 related, 68 unrelated) with a mean follow-up of 3.0+/-1.9 years. The average age of recipients was 44+/-13 years, with a majority being Caucasian (86%) and male (64%). Nineteen (9%) received previous transplants. No patients experienced delayed graft function and 10 (5%) developed acute rejection. Overall, predicted five-year patient survival was 96% and graft survival was 82%. The rates of CMV infection (5%), malignancy (3%), and lymphoproliferative disorder (0.5%) were low. When compared to live-donor kidney transplant recipients nationwide, the center cohort demonstrated improved five year patient (96% center versus 90% national, P=0.0326) and graft survival (82% center versus 79% national, P=0.0901), and a lower one-year acute rejection rate (2% center versus 21 % national, P<0.001).

CONCLUSIONS

In this analysis, the use of Thymoglobulin in live-donor renal transplantation was associated with an absence of delayed graft function, low acute rejection rates, and high patient and graft survival without increasing the risk of infection or lymphoproliferative disorder.

Impact of graft-versus-host disease in reduced-intensity stem cell transplantation (RIST) for patients with haematological malignancies

To clarify the impact of graft-versus-host disease (GVHD) on the outcome of reduced-intensity stem cell transplantation (RIST), 40 patients who received RIST were compared with those who received conventional stem cell transplantation (CST). RIST regimens consisted of either cladribine (0.11 mg/kg/d x 6, n = 13) or fludarabine (30 mg/m(2)/d x 6, n = 27) with busulphan (BU, 4 mg/kg/d orally x 2), with or without antithymocyte globulin (ATG). CST regimens were either cyclophosphamide/total body irradiation (CY/TBI, n = 23), BU/CY (n = 19) or others (n = 6). The RIST group contained more patients who were at high risk of transplant-related mortality, including older patients, while the two groups contained the same percentages of patients at high risk of relapse. There were no differences between these groups in the incidences of acute (grade II-IV, 31.6% RIST vs 33.3% CST, P = 0.6742) and chronic GVHD (56.2%vs 64.1%, P = 0.8512), relapse rate (15.0%vs 18.8%, P = 0.6642), or overall (69.3%vs 65.6%, P = 0.4817) and progression-free survival (64.7%vs 63.8%, P = 0.6920) at d 500. Multivariate analysis of progression-free survival identified only grade III-IV acute GVHD and relapse risk dose as adverse risk factors. Although GVHD is a major threat in RIST, appropriate induction of GVHD may be associated with anti-tumour activity in RIST comparable to that of CST.

Recognition Pattern of Thyroglobulin Autoantibody from Hypothyroid Dogs to Tryptic Peptides of Canine Thyroglobulin

Circulating thyroglobulin autoantibody (TgAA) was analyzed using the Western immunoblot for determination of the dominant epitopes recognized by TgAA on tryptic peptides of canine thyroglobulin (cTg) in hypothyroid dogs. TgAA was measured in hypothyroid dogs, non-hypothyroid dogs with skin diseases and clinically normal dogs. Five of the 7 hypothyroid dogs, 1 of the 8 dogs with skin diseases and 1 of the 4 normal dogs were positive for TgAA. Four of the 5 TgAA-positive hypothyroid dogs were Golden Retrievers, and 3 of them showed high antibody titers. The sera of TgAA positive-dogs reacted to several peptides, and their patterns varied from sample to sample. Sera from 3 dogs with high titers of TgAA reacted broadly to high molecular weight peptides ranging from 45 to 90 kDa. These Western immunoblot patterns of the sera were disappeared after pretreatment with sufficient amount of intact cTg. All serum samples of both TgAA positive dogs and negative controls reacted to low molecular weight peptides ranging from 15 to 20 kDa. These immunoblot patterns of the sera were not disappeared even after pretreatment with sufficient amount of intact cTg. These findings show the possibility that the epitopes recognized by TgAA depend upon individual dogs with hypothyroidism and these autoantibodies recognize conformational epitopes on the cTg molecule.

Suppression of murine experimental autoimmune thyroiditis by oral administration of porcine thyroglobulin

Experimental autoimmune thyroiditis (EAT) induced by the transfer of mouse thyroglobulin (MTg)-immunized spleen cells, activated in vitro with MTg, can be suppressed by oral administration of PTg to donor mice prior to immunization. Oral administration of 1 mg PTg five times over a 10-day period before immunization with MTg-LPS resulted in reduced EAT severity in recipient mice compared with recipients of cells from saline-fed immunized donors. MTg- or PTg-specific proliferative responses were not decreased in PTg-fed donors and anti-MTg antibody was not decreased in the donor mice fed 1 mg PTg. However, anti-MTg antibody production was markedly decreased in recipients of cells from PTg-fed donors compared with recipients of control cells. IgG1, IgG2A, and IgG2B anti-MTg antibody responses were all suppressed by PTg feeding suggesting that tolerance may be induced in both Th1 and Th2 cells. The more severe and histologically distinct granulomatous form of EAT was also suppressed by feeding PTg to donor mice. Studies are underway to determine the mechanism of oral tolerance in this model.

Bioavailability of thyroid hormones from oral replacement preparations

We evaluated gastrointestinal absorption in normal subjects of T4 and T3 from synthetic T3 tablets (Cytomel, SKF), desiccated thyroid tablets (Armour), thyroglobulin tablets (Proloid, Warner-Chilcott) and synthetic L-T4 tablets (Synthroid, Flint and Levothroid, Armour). Measurements of serum T4 and T3 concentrations and free hormone indices were made at multiple times after tablet ingestion, and T3 content in tablets was measured by radioimmunoassay. The time to peak serum T3, and the 26 hr intergrated increment in serum T3, Corrected for the amount if T3 ingested, were not significantly different for 75 micrograms of synthetic T3, 6 grains of desiccated thyroid (containing 99 micrograms T3) and 5 grains of thyroglobulin (containing 90 micrograms T3), the mean integrated increment values for the biological preparations being within 12% of those for synthetic T3. The peak serum T4 concentration, the time to peak T4, and 48 hr integrated increments in serum T4 and T3 were similar after 3 mg of Synthroid and Levothroid. The mean peak serum Free T3 Index after 75 micrograms T3, 500, was much higher than the mean peak Free T3 Index after 3 mg T4, 290. The time to peak Free T3 Index was much less after 75 micrograms T3, 2 hr, than the time to peak after 3 mg T4, 2 days. These results indicate that the time course and extent of T3 absorption do not differ, whether the T3 is given as the synthetic iodothyronine or as part of the thyroid protein, thyroglobulin. This approach appears to be useful in determining bioavailability of thyroid hormones from oral preparations and to assess the possibility of thyroid hormone malabsorption.

[Trophoblastic disease in one ovum in a twin pregnancy]

A case of trophoblastic disease in a twin pregnancy is described from its diagnosis to follow-up after emptying of the uterine cavity. The possible causes of trophoblastic disease are discussed.

Hypertriiodothyroninemia in hypothyroidism treated with thyroglobulin

Hypertriiodothyroninemia during therapy with thyroglobulin was noted in six hypothyroid patients aged 9 to 25 years. Causes of hypothyroidism were thyroiditis, congenital athyreosis, cryptothyroidism, or goitrous hypothyroidism. Serum thyroxine level, measured at the same time, was below normal in three patients. Findings attributable to excess of thyroid hormones were none other than slight nervousness or transitory heat intolerance. Substitution of levothyroxine for thyroglobulin was done in all patients and was associated with return to normal of serum triiodothyronine (T3) values in those tested. A high content of T3 in thyroglobulin used for medication seems the most probable cause of the observed hypertriiodothyroninemia. Since similar findings have been reported previously for hypothyroid patients treated with desiccated thyroid preparations, it seems clear that therapy with levothyroxine offers a significant advantage over the use of desiccated thyroid or thyroglobulin.

Drug therapy reviews: management of hypothyroidism

The therapeutic management of hypothyroidism caused by deficient thyroid hormone production is discussed. The therapeutic use of the following thyroid agents is reviewed: levothyroxine sodium, Thyroid USP, thyroglobulin, liotrix, and liothyronine sodium. Myxedema coma, neonatal hypothyroidism, primary hypothyroidism, and secondary and tertiary hypothyroidism are specific hypothyroid states for which drug therapy is discussed. Levothyroxine sodium is the preferred agent because of consistent potency, restoration of normal, constant serum levels of thyroxine (T4) and triiodothyronine (T3) and ease of interpretation of thyroid hormone levels. Other agents, because they contain T3, result in postabsorptive elevated T3 serum concentrations that may cause thyrotoxic symptoms and reduction of T4 levels. This, in turn, may give rise to misleading estimates of thyroid dosage. Patients with the sick euthyroid or low T3 syndromes are not candidates for thyroid hormone therapy.

Problems in diagnosis and treatment of lupus psychosis. Report of a patient with systemic lupus erythematosus, Hashimoto's thyroiditis, and Sjögren's syndrome

A 34-year-old woman with an organic psychosis was presumed to be suffering from corticosteroid psychosis because of prednisone treatment for urticaria. Lupus was found to be the cause of both urticaria and psychosis. The lupus psychosis was reversed when sufficiently high doses of steroids were given, in combination with immunosuppressant agents.