5mCi pretreatment scanning does not cause stunning when the ablative dose is administered within 72 hours

• Autor(a) principal: Rosário,Pedro Weslley S.
• Data de Publicação: 2005
• Outros Autores: Barroso,Álvaro Luís, Rezende,Leonardo L., Padrão,Eduardo Lanza, Maia,Frederico F. Ribeiro, Fagundes,Tales A., Purisch,Saulo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Arquivos Brasileiros de Endocrinologia & Metabologia (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0004-27302005000300014
• topic: Scanning; Stunning; Thyroid carcinoma

OBJECTIVE: To determine the stunning effect of a tracer dose of 5mCi iodine-131. PATIENTS AND METHODS: We retrospectively analyzed 145 patients who received the first ablative treatment at our service. Patients were divided according to disease status determined upon post-treatment scanning (101 patients with thyroid remnants and 44 with pulmonary metastases) and whole-body scanning before ablation (performed on 69 individuals). All patients with thyroid remnants were treated with an ablative dose of 100mCi and those with metastases received 200mCi. RESULTS: In patients with remnants only (n= 41) or metastases (n= 28) submitted to diagnostic scanning, uptake was found to be apparently increased in most patientscases (71 and 73%, respectively) 7 days after therapy, while reduced uptake (visual) was not observed in any patient. The efficacy of ablation was similar in the groups submitted or not to diagnostic scanning: 71 and 80% in patients without metastases (p= 0.28), respectively, and 43 and 50% in those with pulmonary involvement (p= 0.64). CONCLUSION: The present results indicate that diagnostic scanning using a 5mCi iodine-131 dose does not interfere with uptake of the ablative dose or with treatment efficacy when ablation is performed within 72h.