THYROID FUNCTION IN MALIGNANT PEDIATRIC PATIENTS AFTER RADIOTHERAPY
Abstract
Introduction. Malignancy is seen in pediatrics, frequently. Radiotherapy as a common procedure in malignancy management may has many side effects and complications, especially about endocrine system. In this study, we evaluate the incidence of post radiotherapy hypothyroidism In malignant pediatric patients.
Methods. In a cross sectional study one hundred and eighty children between 1 to 20 years old that survived of malignancy were selected. They have been treated in Sayyed-Alshohada hospital (affiliated to Isfahan University of Medical Sciences) from 1993 Sep. until 1998 Sep. by radiotherapy.
Baseline characteristics (e.g. sex, age, dose, location and number of radiotherapy fraction, type of malignancy) were derived from medical records. Subjects were invited by letters to evaluate their thyroid functions in 1999. Serum T4 and FT4 concentrations assayed by RIA and TSH by IRMA methods.
Results. The incidence of hypothyroidism was 13.3 percent (1.2 percent secondary hypothyroidism and 12.1 percent primary hypothyroidism). There was no statistical difference in age and sex distribution between patients with or without hypothyroidism. History of cervical region radiotherapy was taken in 45.8 percent of hypothyroid patients. There was no significant difference in dose and number of radiotherapy fraction between hypothyroid and euthyroid patients.
Discussion. Radiotherapy may have a role in developing hypothyroidism in patients who received radiotherapy. This role has no relation to age and sex, dose and number of radiation fraction in development of hypothyroidism. Region of radiotherapy is important. It is suggested that this study continues and data will be collected during several years in future. Of course, many of hypothyroid patients will become euthyroid spontaneously.
Methods. In a cross sectional study one hundred and eighty children between 1 to 20 years old that survived of malignancy were selected. They have been treated in Sayyed-Alshohada hospital (affiliated to Isfahan University of Medical Sciences) from 1993 Sep. until 1998 Sep. by radiotherapy.
Baseline characteristics (e.g. sex, age, dose, location and number of radiotherapy fraction, type of malignancy) were derived from medical records. Subjects were invited by letters to evaluate their thyroid functions in 1999. Serum T4 and FT4 concentrations assayed by RIA and TSH by IRMA methods.
Results. The incidence of hypothyroidism was 13.3 percent (1.2 percent secondary hypothyroidism and 12.1 percent primary hypothyroidism). There was no statistical difference in age and sex distribution between patients with or without hypothyroidism. History of cervical region radiotherapy was taken in 45.8 percent of hypothyroid patients. There was no significant difference in dose and number of radiotherapy fraction between hypothyroid and euthyroid patients.
Discussion. Radiotherapy may have a role in developing hypothyroidism in patients who received radiotherapy. This role has no relation to age and sex, dose and number of radiation fraction in development of hypothyroidism. Region of radiotherapy is important. It is suggested that this study continues and data will be collected during several years in future. Of course, many of hypothyroid patients will become euthyroid spontaneously.
Keywords
PEDIATRIC ONCOLOGY, HYPOTHYROIDISM, RADIOTHERAPY, MALIGNANCY