[Preliminary results of thyroid function assessment in children and adolescents with Hodgkin's disease (HD) treated according to PGP-HD-97 protocol]

Abstract

The intensive treatment of HD (multidrug chemotherapy combined with radiotherapy) carries the risk of early and late complications. One of the late effects is thyroid dysfunction which may occur after radiotherapy of the cervical region. In this report preliminary results of thyroid function assessment in children with HD in correlation with time after cessation of therapy are presented. Between January 1, 1997 and December 31, 2002, 58 children with HD (age: 2.6-18.3 years, median, 14.9 years) were treated in Department of Pediatric Oncology and Hematology PAIP CMUJ in Kraków, according to PGP-HD-97 protocol and these patients were included in the study. Multidrug chemotherapy combined with low-dose involved-field radiotherapy (15-25 Gy) was used in treatment of these children. Therapy was completed in all of analysed patients and in 38 of them (65.5%) at least 24 months before the end of observation. Physical and ultrasound examination of thyroid gland, and plasma levels of T3, T4, fT3, fT4, and TSH were measured before treatment of HD, before the treatment cessation, and every 6-12 months after the completion of therapy. The observation was completed on December 31, 2003. Six hundred and twelve measurements were performed in all of patients. At least one abnormal result of thyroid hormones or TSH levels was found in 50% of children. The most frequent abnormality was the increased level of TSH which occurred in 27.6% of patients. The rates of abnormal results of TSH concentration before HD treatment, and 1 year, 2 years, and later than 2 years after the cessation of therapy were: 8.3%, 8.8%, 21,4%, and 10.2%, respectively. These differences were not statistically significant. Seven patients (12%) require endocrinological treatment due to thyroid dysfunction. These patients as well as other analysed children are clinically euthyreotic. Initial results of thyroid function assessment presented in this report indicate that longer follow up and further thyroid function tests, physical and ultrasound examination of thyroid gland in patients after HD therapy cessation are needed. These studies are essential to early detection and adequate treatment of early and late complications of HD therapy.