Is thyroid stunning clinically relevant? A retrospective analysis of 208 patients

Abstract

Objective: Current guidelines have advised against the performance of 131 I-iodide diagnostic whole body scintigraphy (dxWBS) to minimize the occurrence of stunning, and to guarantee the efficiency of radioiodine therapy (RIT). The aim of the study was to evaluate the impact of stunning on the efficacy of RIT and disease outcome. Subjects and methods: This retrospective analysis included 208 patients with differentiated thyroid cancer managed according to a same protocol and followed up for 12-159 months (mean 30 ± 69 months). Patients received RIT in doses ranging from 3,700 to 11,100 MBq (100 mCi to 300 mCi). Post-RIT-whole body scintigraphy images were performed 10 days after RIT in all patients. In addition, images were also performed 24-48 hours after therapy in 22 patients. Outcome was classified as no evidence of disease (NED), stable disease (SD) and progressive disease (PD). Results: Thyroid stunning occurred in 40 patients (19.2%), including 26 patients with NED and 14 patients with SD. A multivariate analysis showed no association between disease outcome and the occurrence of stunning (p = 0.3476). Conclusion: The efficacy of RIT and disease outcome do not seem to be related to thyroid stunning. Arq Bras Endocrinol Metab. 2014;58(3):292-300 Keywords Thyroid cancer; radioiodine therapy; radionuclide scintigraphy; stunning; 131 I-iodide RESUMO Objetivo: As diretrizes atuais alertam contra a execução da cintigrafia de corpo inteiro com iodo-131 (dxWBS) para minimizar a ocorrência de atordoamento e garantir a eficiência do tratamento com radioiodo (RIT). O objetivo deste estudo foi avaliar o impacto do atordoamento sobre a eficácia do RIT e desfechos da doença. Sujeitos e métodos: Esta análise retrospectiva incluiu 208 pacientes com câncer diferenciado de tireoide submetidos ao mesmo protocolo e acompanhados por 12-159 semanas (média de 30 ± 69 meses). Os pacientes receberam RIT com doses variando de 3.700 a 11.100 MBq (100 mCi a 300 mCi). As imagens da cintigrafia após a RIT foram feitas 10 dias depois da RIT em todos os pacientes. Além disso, as imagens foram também obtidas após 24-48h em 22 pacientes. O desfecho foi classificado como nenhuma evidência de doença (NED), doença estável (SD) e doença progressiva (PD). Resultados: O atordoamento da tireoide ocorreu em 40 pacientes (19,2%), incluindo 26 pacientes com NED e 14 pacientes com SD. A análise multivariada não mostrou associação entre o desfecho da doença e a ocorrência de atordoamento (p = 0,3476). Conclusão: A eficácia da RIT e o desfecho da doença não parecem estar relacionados com o atordoamento da tireoide. Arq Bras Endocrinol Metab. 2014;58(3):292-300Descritores

CACA guidelines for holistic integrative management of thyroid cancer

“…Structural or functional imaging examinations is helpful to further identify the location, size, number, and extent of invasion of RAIR-DTC lesions [1,[158][159][160][161][162][163][164], providing the evidence for appropriate treatment strategies [165,166]. In addition, ongoing Tg monitoring not only contributes to evaluate the response to 131 I therapy, but also has a certain value in predicting RAIR-DTC [167].…”