Background: Thyroid remnant ablation of differentiated thyroid carcinoma (DTC) patients is traditionally performed after levothyroxine withdrawal. Recombinant human TSH (rhTSH) administration increases serum TSH levels without inducing hypothyroidism.Aim: To investigate the frequency of chromosome translocations in DTC patients after the first (131)I therapeutic dose and, to compare the frequency of translocations between DTC patients off levothyroxine and those receiving rhTSH. Patients and methods: A total of 20 DTC patients were randomly assigned to levothyroxine withdrawal [(30 days) group A; n=10, 9 women; mean age 48.5+/-19.2 yrs] or to rhTSH injections [(0.9 mg im/2 consecutive days) group B; n=10, 8 women; mean age 50.4+/-18.8 yrs] before undergoing (131)I activity (3.7 GBq). The frequency of translocations in peripheral lymphocytes was analysed by tricolour fluorescence in situ hybridization (FISH) with whole-chromosome-specific probes for chromosomes 1, 4 and 8. Lymphocytes were stained routinely (about 500 each time). Results: The two groups showed similar baseline translocation frequency. After (131)I administration, the total chromosomal translocation rate was significantly lower in group B than in group A (p=0.02). The frequency of translocations increased significantly in group A only (p=0.01 vs baseline). Rearrangement specifically involved chromosomes 4 and 8 (p=0.02 vs baseline). Conclusions: our preliminary data show that in hypothyroid status (131)I ablation therapy induces a higher translocation rate, especially in chromosomes 4 and 8. This finding, in agreement with previous dosimetric reports, suggests that while inducing a low extra-thyroid exposure rhTSH reduces the potential risk of chromosomal aberration associated with blood irradiation.PMID: [PubMed - as supplied by publisher]

Chromosome translocation frequency after radioiodine thyroid remnant ablation: a comparison between rhTSH stimulation and prolonged levothyroxine withdrawal.

DANESE, Elisa;MOGHETTI, Paolo;FERDEGHINI, Marco
2009-01-01

Abstract

Background: Thyroid remnant ablation of differentiated thyroid carcinoma (DTC) patients is traditionally performed after levothyroxine withdrawal. Recombinant human TSH (rhTSH) administration increases serum TSH levels without inducing hypothyroidism.Aim: To investigate the frequency of chromosome translocations in DTC patients after the first (131)I therapeutic dose and, to compare the frequency of translocations between DTC patients off levothyroxine and those receiving rhTSH. Patients and methods: A total of 20 DTC patients were randomly assigned to levothyroxine withdrawal [(30 days) group A; n=10, 9 women; mean age 48.5+/-19.2 yrs] or to rhTSH injections [(0.9 mg im/2 consecutive days) group B; n=10, 8 women; mean age 50.4+/-18.8 yrs] before undergoing (131)I activity (3.7 GBq). The frequency of translocations in peripheral lymphocytes was analysed by tricolour fluorescence in situ hybridization (FISH) with whole-chromosome-specific probes for chromosomes 1, 4 and 8. Lymphocytes were stained routinely (about 500 each time). Results: The two groups showed similar baseline translocation frequency. After (131)I administration, the total chromosomal translocation rate was significantly lower in group B than in group A (p=0.02). The frequency of translocations increased significantly in group A only (p=0.01 vs baseline). Rearrangement specifically involved chromosomes 4 and 8 (p=0.02 vs baseline). Conclusions: our preliminary data show that in hypothyroid status (131)I ablation therapy induces a higher translocation rate, especially in chromosomes 4 and 8. This finding, in agreement with previous dosimetric reports, suggests that while inducing a low extra-thyroid exposure rhTSH reduces the potential risk of chromosomal aberration associated with blood irradiation.PMID: [PubMed - as supplied by publisher]
2009
Chromosome translocation frequency; rhTSH; levothyroxine
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11562/330409
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