Primary hypothyroidism commonly occurs after radiotherapy(RT),and coincides with increased circulating thyroid-stimulating hormone(TSH)levels.We tested therefore the protective effect of suppressing TSH with L-thyroxi...Primary hypothyroidism commonly occurs after radiotherapy(RT),and coincides with increased circulating thyroid-stimulating hormone(TSH)levels.We tested therefore the protective effect of suppressing TSH with L-thyroxine during RT for medulloblastoma/PNET and Hodgkin lymphoma(HL)in a prospective cohort study.From 1998 to 2001,a total of 37 euthyroid children with medulloblastoma/PNET plus 14 with HL,scheduled for craniospinal irradiation and mediastinum/neck radiotherapy,respectively,underwent thyroid ultrasound and free triiodothyronine(FT3),free thyroxine(FT4),and TSH evaluation at the beginning and end of craniospinal iiradiation.From 14 days before and up to the end of radiotherapy,patients were administered L-thyroxine checking every 3 days TSH to ensure a value<0.3μIU/mL.During follow-up,blood tests and ultrasound were repeated;primary hypothyroidism was considered an increased TSH level greater than normal range.Twenty-two/37 patients with medulloblastoma/PNET and all the 14 patients with HL were alive after a median 231 months from radiotherapy with 7/22 and 8/14 having correctly reached TSH levels˂0.3μIU/mL and well matched for other variables.Twenty years on,hypothyroidism-free survival rates differed significantly,being 60%±15%and 15.6%±8.2%in TSH-suppressed vs.not-TSH suppressed patients,respectively(P=0.001).These findings suggest that hypothyroidism could be durably prevented in two populations at risk of late RT sequelae,but it should be confirmed in a larger cohort.展开更多
文摘Primary hypothyroidism commonly occurs after radiotherapy(RT),and coincides with increased circulating thyroid-stimulating hormone(TSH)levels.We tested therefore the protective effect of suppressing TSH with L-thyroxine during RT for medulloblastoma/PNET and Hodgkin lymphoma(HL)in a prospective cohort study.From 1998 to 2001,a total of 37 euthyroid children with medulloblastoma/PNET plus 14 with HL,scheduled for craniospinal irradiation and mediastinum/neck radiotherapy,respectively,underwent thyroid ultrasound and free triiodothyronine(FT3),free thyroxine(FT4),and TSH evaluation at the beginning and end of craniospinal iiradiation.From 14 days before and up to the end of radiotherapy,patients were administered L-thyroxine checking every 3 days TSH to ensure a value<0.3μIU/mL.During follow-up,blood tests and ultrasound were repeated;primary hypothyroidism was considered an increased TSH level greater than normal range.Twenty-two/37 patients with medulloblastoma/PNET and all the 14 patients with HL were alive after a median 231 months from radiotherapy with 7/22 and 8/14 having correctly reached TSH levels˂0.3μIU/mL and well matched for other variables.Twenty years on,hypothyroidism-free survival rates differed significantly,being 60%±15%and 15.6%±8.2%in TSH-suppressed vs.not-TSH suppressed patients,respectively(P=0.001).These findings suggest that hypothyroidism could be durably prevented in two populations at risk of late RT sequelae,but it should be confirmed in a larger cohort.
