Effect of 1110 MBq Radioiodine in Reducing Thyroid Volume in Multinodular Goiter: A New Protocol.

BACKGROUND: There is no consensus on the optimal treatment of multinodular goiter (MNG), but in the past few years, the use of radioiodine has increased. This study's objective was to evaluate adjuvant methimazole (MMI) therapy to increase and standardize radioiodine uptake (RAIU) with a fixed therapeutic (131)I dose of 1110 MBq (30 mCi). METHODS: Our study included 5 women with MNG treated with MMI, 10 - 15 mg/day for 2 to 4 months, prior to the administration of 1110 MBq (131)I (30 mCi); none of the patients developed hypothyroidism during MMI therapy and had average basal TSH levels of 0.32 ± 0.39 mIU/L that increased to 2.6 ± 0.9 mIU/L (P = 0.07). RESULTS: RAIU increased from 25.6 ± 8.7% to 49.2 ± 8.3% (P = 0.003). All patients were followed for 12 months: median thyroid volume (TV) decreased from 77.2 mL (32.9 - 124.2) to 48.8 ml (12.4 - 68.9) with an average decrease of 46.4 ± 14.8% (P = 0.01). All patients developed hypothyroidism during the first 6 months after radioiodine therapy. CONCLUSIONS: This new therapeutic protocol using MMI as adjuvant therapy is effective in increasing RAIU as well as the deleterious effects of (131)I, without increasing the required dose, but leading to thyroid volume decreases similar to those reported with the use of recombinant human thyrotropin (rhTSH) or higher radioiodine doses.

Specificity and sensitivity of 99mTc-EDDA/HYNIC-Tyr³-octreotide (99mTc-TOC) for imaging neuroendocrine tumors.

OBJECTIVES: Gastroenteropancreatic neuroendocrine tumors (NETs) are cancers originating from neuroendocrine organs such as the pancreas, pituitary, thyroid, and adrenal glands and tumors arising from the diffuse neuroendocrine cells that are widely distributed throughout the body. NETs express somatostatin (SS) and contain a high density of SS receptors; therefore, they can be specifically targeted with SS-based radiopharmaceuticals. The aim of this research was to determine the validity in terms of specificity, sensitivity, and the agreement beyond chance with the biopsy (gold standard) of the 99mTc-EDDA-HYNIC-Tyr³octreotide (99mTc-TOC) to image and localize NETs and their metastases. MATERIALS AND METHODS: Freeze-dried kits containing 0.0125 mg HYNIC-octreotide and co-ligands were easily labeled and quality controlled within the hospital radiopharmacy. Fifty-six consecutive Mexican patients with a previous presumptive diagnosis of NETs underwent several clinical and laboratory studies and were referred to the Nuclear Medicine Department for a routine scan with 99mTc-TOC. The patients were injected with 500-600 MBq 99mTc-TOC, and whole-body images were obtained 2 h later with a SPECT or a SPECT/CT camera. Two nuclear medicine physicians observed the images and classified them as 17 negative and 39 positive. After correlating the image of each patient with our 'gold standard' (biopsy, clinical history, morphological images, and tumor marker assays), the 99mTc-TOC images were classified by the same two physicians as 12 true negatives, five false negatives, 38 true positives and one false positive. RESULTS: The validity of 99mTc-TOC in terms of relative frequencies with corresponding 95% confidence intervals were as follows: 92.3% (64-100%) specificity; 88.4% (78-97%) sensitivity; and the agreement beyond chance was 73% (60-84%). The positive predictive value was 97.4% (87-100%); the negative predicted value was 70.6% (48-93%); the accuracy was 89.3% (89-97%); and the prevalence was 76.8% (64-87%). CONCLUSION: Because of these high values, we strongly recommend scintigraphy with the Mexican-produced 99mTc-TOC for the localization of NETs and their metastases, and we conclude that it is a good tool for detecting neuroendocrine disease in a Mexican population.

[Trends of thyroid pathology in a referral center: steady prevalence of papillary thyroid carcinoma but goiter increase in thyroidectomies]. / Tendencias en patología tiroidea en un centro de referencia: prevalencia estable del carcinoma papilar e incremento de hiperplasia nodular en tiroidectomías.

INTRODUCTION: Changes in the prevalence of papillary thyroid carcinoma (PTC) have been reported in institutions and national cancer registries. OBJECTIVE: To describe time trends in benign and malignant thyroid diseases in a national endocrine referral center. MATERIALS AND METHODS: Systematic review and classification of consecutive specimens with slides/paraffin blocks in surgical pathology archives (January 1990 to December 2009). Institutional registries, size, type of surgery and number of inclusion blocks were recorded. Patients whose registries were granted before January 1990 without nodules, but treated after twelve months for a suspicious thyroid lesion, were included. These patients in a passive follow-up permitted incidence density calculations. Cases were grouped by quinquennium. RESULTS: Institutional registers were conceded to 103,961 persons worthy of attention, and 1,269 were submitted to thyroidectomies (1.2%). One hundred twenty four patients none treated for thyroid diseases before 1990, developed thyroid nodules after 1991. The incidence density for goiter was 0.05 person/year and for PTC 0.04 person/year in that group. In all series woman to man relation was 9:1 with a mean age of 45 years. Total or near total thyroidectomies were performed in 60% patients and benign diseases were diagnosed in 732 (52%) cases. Thyroid surgeries increased since 2005 (p=0.03) with a rise in goiter prevalence (0.25, 0.31, 0.35, 0.38, p for trend 0.0005), without significant increase in PTC prevalence (0.41, 0.43, 0.35, 0.40, p for trend 0.71) in thyroidectomies. CONCLUSIONS: Goiter as the only finding in thyroid specimens increased 52% in the last 20 years. PTC prevalence is steady with a higher number of tumors<3 cm.

Radioiodine treatment in autoimmune hyperthyroidism: analysis of outcomes in relation to dosage.

BACKGROUND: Controversy exists regarding the optimal dose of radioiodine ((131)I) therapy in autoimmune hyperthyroidism (i.e., Graves' Disease). METHODS: In order to evaluate the efficacy and safety of high dose (131)I therapy in autoimmune hyperthyroidism, a retrospective review of patients who received (131)I therapy for Graves' disease from 1980 to 2000 in the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City was carried out. RESULTS: The study population consisted of 596 autoimmune hyperthyroid patients with a mean age of 35 years. The mean follow-up period was 10.31 +/- 2.37 years. Remission of hyperthyroidism occurred in 81.9%, persistent hyperthyroidism was recorded in 14.4% and recurrence in 3.7%. (131)I doses of 5-9 mCi (185-333 MBq) and > or =20 mCi (> or =740 MBq) were associated with remission rates of 65.5% and 87.7% respectively. Remission occurred earlier and more often with high doses of (131)I. The high-dose group (20-30 mCi [740-1110 MBq]) had the lowest rate of persistence (9.7, 27.5 and 34.3%, for 20-30 [740-1110 MBq], 10-14 [370-518 MBq] and 5-9 [185-333 MBq] mCi, respectively p <0.05) and hypothyroidism occurred earlier in this group (p = 0.05). CONCLUSIONS: Remission of autoimmune hyperthyroidism is more likely with doses of 20-30 mCi (740-1110 MBq).

HLA study on two Mexican Mestizo families with autoimmune thyroid disease.

Several studies have been done regarding the genetic susceptibility to autoimmune thyroid disease, particularly those related to the role of Major Histocompatibility Complex (MHC) genes in the etiology of the disease. In the present study, we report class I and class II MHC haplotypes in nine individuals affected by Hashimoto thyroiditis and Graves' disease who belong to two distinct Mexican families. In one of the families, Hashimoto thyroiditis was associated with the Human Leukocyte Antigen (HLA) HLA-DR3 allele whereas in the other family the disease was associated with homozygosity for the HLA-DR4 (DRB1*0407), HLA-DQ3 (DQB1*0302) haplotype. On the other hand, Graves' disease was found to be associated in one of the families with HLA-DR2 (DRB1*1501) and in the other with homozygosity for the HLA-DR7 (DRB*0701) and HLA-DQ2 (DQB1*0201) haplotype. These results confirm that in Mexicans as in other ethnic groups, genes located within the MHC region are related to the genetic susceptibility to develop autoimmune thyroid disease.

Nódulo tiroideo: estudio de 88 casos / Thyroid nodules: prospective study of 88 patients

Objetivo. Conocer en forma prospectiva las características clínicas, resultados de los exámenes de gabinete, citología por aspiración con aguja fina (BAAF), biopsia por punción ("tru-cut"), respuesta a las diferentes modalidades terapeúticas, así como el resultado histopatológico definitivo de 19/88 pacientes operados por la presencia de un nódulo tiroideo. Diseño del estudio. Estudio de cohortes en el cual se utilizaaron diferentes tipos de maniobras. Se incluyeron 88 pacientes con un nódulo tiroideo vistos en 1985 y 1986 y con seguimiento de 5 ñ 2 años. Sitio del estudio. Clínica de tiroides del Instituto Nacional de la Nutrición Salvador Zubirán (tercer nivel). Pacientes. Se informan los resultados del estudio de 88 pacientes con el seguimiento mencionado, de un grupo original de 100 pacientes, con edad promedio de 42 ñ 15 años, 18-79 con predominio del sexo femenino (94 por ciento). Resultados. La mayoría de los nódulos midieron 1 a 4 cm (70 por ciento) y tuvieron consistencia aumentada. Desde el punto de vista gamagráfico, 62 por ciento fueron no funcionantes, 22 por ciento funcionantes y 13 por ciento hiperfuncionantes. Por ultrasonido (US), 80 por ciento tuvieron patrón sólido o mixto, 13 por ciento quístico, 6 por ciento correspondieron a bacio multinodular y 1 por ciento a bocio simple. La citología o biopsia por aspiración con aguja fina o percutánea por punción permitieron establecer el diagnóstico de malignidad en el 75 por ciento de los casos en el 90 por ciento cuando se practicaron ambos procedimientos. Se documentaron neoplasias malignas en el 20 por ciento de los nódulos no funcionantes, en el 10 por ciento de los funcionantes y en ninguno de los hiperfuncionantes; en relación al us, en el 17 por ciento de los de apariencia sólida, en el 19 por ciento de los mixtos y en el 9 por ciento de los quísticos. Se utilizó la escleroterapia en nódulos quísticos o mixtos pero predominantemente quísticos con reducción significativa en 79 por ciento de los casos. Once pacientes recibieron 131l, siete con nódulos hiperfuncionantes y el resto funcionantes. Sesenta y dos pacientes recibieron tratamiento con hormonas tiroideas, con reducción mayor al 50 por ciento en 40 a 45 por ciento de los casos. A la fecha se han operardo 19 pacientes (21 por ciento) de los cuales 58 por ciento han tenido neoplasias malignas. En ningún caso el diagnóstico se ha establecido en forma tardía. La prevalencia de cáncer de tiroides en nuestra serie es de 13 por ciento (11 c

Bocio difuso tóxico tratado con 131: treinta años de experiencia / Diffuse toxic goiter treated with 131: 30 years' experience

Se analizaron en forma retrospectiva las características y la evolución de 1178 pacientes tratados con I de 1953 a 1983. Del total, 865 (72.6%) requirieron unasola dosis y el resto dos o más. Las dosis únicas promedio fueron de 1953 a 1963 7.1 ñ 1.7 mCi, de 1963 a 1973 6.3 ñ 2.8 mCi y de 1973 a 1983 8.2 ñ 2.6 mCi. La incidencia de hipotiroidismo al primer año de observación post tratamiento fue de 10%, 15.49% y 38.86% respectivamente. La administración de <- 6 mCi ó > 6 mCi, no influyó significativamente en la frecuencia de hipotiroidismo de 1953 a 1963 y de 1973 a 1983. En la década de 1963 a 1973 probablemente un mayor número de pacientes con bocios pequeños recibieron radioyodo, explicando la observación de que con dosis bajas de I hubo una mayor incidencia de mixedema al primer año de observación. Al separar a los pacientes tratados de 1980 a 1983 en que las dosis de I fueron mayores (X = 10.0 ñ 2.7 mCi), el porcentaje de hipotiroidismo ascendió a 53.1% al año de observación. Analizados por el método actuarial, los pacientes menores de 40 años desarrollaron más frecuentemente hipotiroidismo al año y a los seis años de observación

Biopsia percutanea de tiroides (BPT): análisis retrospectivo de 100 casos / Percutaneus biopsy of the thyroid gland: retrospective analysis of 100 cases

Se analiza retrospectivamente la experiencia de los últimos 10 años en la realización de la BTP en el Instituto Nacional de la Nutrición Salvador Zubirán (INNSZ). Se resume la descripción de la técnica. Hubo 6 pacientes del sexo masculino y 94 del femenino. La edad promedio fue de 32.6 años. Se obtuvo muestra adecuada para diagnóstico histológico en 93 casos. Existió concordancia del 90% entre el diagnóstico de la biopsia y el de la pieza quirúrgica en los casos operados. Cuatro pacientes presentaron complicaciones leves. El 89.27% de los diagnósticos microscópicos correspondió a padecimientos benignos y el 10.73% a malignos. La biopsia fue determinante en la indicación quirúrgica en 15 casos, no la modificó 5 yla contraindicó en 46. Sólo 9 de 31 pacientes sospechosos de neoplasia maligna fueron confirmados por biopsia, reduciéndose así en un 70% las intervenciones quirúrgicas por este concepto. Las principales indicaciones de la biopsia fueron la sospecha de tiroiditis y de carcinoma. Se concluye que el procedimiento analizando es un método útil, sencillo y económico en el diagnóstico de la patología tiroidea, que añade evidente y definitiva información a la obtenida por la clínica