Clinical characteristics and long-term outcomes for parapharyngeal metastases of well-differentiated thyroid cancer during 131 I therapy and follow-up.

OBJECTIVE: Parapharyngeal metastases (PPM) are rarely observed in patients with well-differentiated thyroid cancer (WDTC). Radioiodine (131 I) therapy has been the main treatment for metastatic and recurrent DTC after thyroidectomy. This study was performed to evaluate the clinicopathological features and long-term outcomes associated with survival of patients with PPM at the end of follow-up. DESIGN: In total, 14,984 consecutive patients with DTC who underwent 131 I therapy after total or near-total thyroidectomy from 2004 to 2021 were retrospectively reviewed. Therapeutic efficacy was evaluated using the Response Evaluation Criteria in Solid Tumours v1.1 and logistic regression analysis. The disease status was determined using dynamic risk stratification. Disease-specific survival (DSS) was assessed using the Kaplan-Meier method and a Cox proportional hazards model. PATIENTS: Seventy-five patients with PPM from WDTC were enroled in this study. Their median age at the initial diagnosis of PPM was 40.2 ± 14.1 years, and the patients comprised 32 men and 43 women (male:female ratio, 1.00:1.34). Of the 75 patients, 43 (57.33%) presented with combined distant metastases. Fifty-seven (76.00%) patients had 131 I avidity and 18 had non-131 I avidity. At the end of follow-up, 22 (29.33%) patients showed progressive disease. Sixteen of the 75 patients died; of the remaining 59 patients, 6 (8.00%) had an excellent response, 6 (8.00%) had an indeterminate response, 10 (13.33%) had an biochemical incomplete response, and 37 (49.33%) had a structural incomplete response. Multivariate analysis confirmed that age at initial PPM diagnosis, the maximal size of PPM, and 131 I avidity had significant effects on progressive disease of PPM lesions (p = .03, p= .02, and p < .01, respectively). The 5- and 10-year DSS rates were 98.49% and 62.10%, respectively. Age of ≥55 years at initial diagnosis of PPM and the presence of concomitant distant metastasis were independently associated with a poor prognosis (p = .03 and p = .04, respectively). CONCLUSION: The therapeutic effect for PPM was closely associated with 131 I avidity, age at initial PPM diagnosis, and maximal size of PPM at the end of follow-up. Age of ≥55 years at initial diagnosis of PPM and the presence of concomitant distant metastasis were independently associated with poor survival.

Condutas atuais no manuseio do carcinoma diferenciado da tireoide / Current conducts in the handling of differentiated thyroid carcinoma

JUSTIFICATIVA E OBJETIVOS: Os carcinomas diferenciados da tireoide (CDT) são neoplasias de elevada incidência e bom prognóstico. Contudo, apresentam taxa de recidiva relativamente alta e controvérsias quanto à abordagem diagnóstica e terapêutica. O objetivo deste estudo foi abordar as particularidades do tratamento cirúrgico e radioiodoterápico, bem como o recente uso do hormônio recombinante da tireoide humano (TSHrh) no diagnóstico, tratamento e seguimento do CDT. CONTEÚDO: A maioria dos cânceres de tireoide são carcinomas bem diferenciados, cujo subtipo folicular e papilífero são os mais comuns. O tratamento dessas doenças consiste, em síntese,de cirurgia, seguida da ablação do tecido remanescente com radioiodoterapia(RIT) com Iodo-131 (I131) e terapêutica substitutiva com levotiroxina de forma contínua. No seguimento e tratamento desses pacientes ganhou destaque atualmente o uso doTSHrh, principalmente por driblar efeitos nocivos da retirada da levotiroxina. Contudo, as estratégias diagnósticas e terapêuticas não estão completamente estabelecidas e buscam-se consensos nas sociedades nacionais e internacionais. CONCLUSÃO: Atualmente a tireoidectomia total seguida de RIT está indicada para todos os pacientes com CDT. A RIT complementar, no entanto, é dispensada; somente para os tumores de muito baixo risco e completamente ressecados. No presente momento o TSHrh mostra-se como opção segura a suspensão da levotiroxina.

BACKGROUND AND OBJECTIVES: The differentiated thyroid carcinoma (DTC) is a cancer with high incidence and good prognosis. However, it has relatively high recurrence rate and controversies regarding the diagnostic and therapeutic approaches.This paper deals with the particularities of surgical treatment and radioiodine therapy and the recent use of recombinant human thyroid-stimulating hormone (rhTSH) in the diagnosis, treatment and follow-up of DTC. CONTENTS: The most of thyroid cancers are well differentiated carcinomas, papillary and follicular subtypes are the most common.The treatment of these disorders is, in short, surgery followed by ablation of remnant tissue with radioiodine therapy (I131) and replacement therapy with levothyroxine continuously. In the following and treatment of these patients gained prominence the current use of rhTSH, mainly to circumvent the harmful effects of levothyroxine withdrawal. However, the diagnostic and therapeutic strategies are not established in a concise and national and international societies seek for consensus. CONCLUSION: Currently a total thyroidectomy followed by RIT is indicated for all patients with DTC. RIT complement,however, is not required for very low-risk tumors and completely resected. At present the rhTSH emerges as a safe option to levothyroxine withdrawal.