RESUMEN
Radiopharmaceutic tracers are used commonly to diagnose and monitor benign and malignant conditions of the genitourinary system. Most often, these tracers assess renal function and obstruction in "normal" and transplanted renal units. More recently, especially with the advent of positron emission tomography (PET)/CT, the role of nuclear pharmaceutics in the staging and monitoring of malignancies has expanded.
Asunto(s)
Enfermedades Urológicas/diagnóstico por imagen , Humanos , Enfermedades Renales/diagnóstico por imagen , Cintigrafía , Radiofármacos , Neoplasias Urológicas/diagnóstico por imagenRESUMEN
BACKGROUND: Successful thyroid tissue ablation of patients with well-differentiated thyroid cancer can be defined by a negative whole-body scan (WBS) and/or an undetectable thyroglobulin (Tg). Variables associated with success are poorly understood. Tg measurement, although more sensitive than WBS, has not been firmly established as the sole monitoring method. In a previous study, we retrospectively evaluated the variables associated with scintigraphic success. Ablation dose (AD) was the only variable associated with success (odds ratio (OR): 1.96 per 1.85 GBq increment; 95% confidence interval (CI)=1.11-3.46). OBJECTIVES: (1) To determine if the variables associated with success are the same using Tg. (2) To determine whether Tg measurement can become the sole method for assessing ablation success. METHODS: We performed the analysis using a Tg level <2 ng.ml-1 as a criterion for completed ablation. Data were available from 109 patients. RESULTS: Univariate analysis showed an effect of stage (OR=0.05; 95% CI=0.01-0.23) and female sex (OR=2.8; 95% CI=1.14-6.89). Multivariate analysis demonstrated only stage to be a significant predictor of success. Ablation was successful by both methods in 62/109 patients and it failed by both in 10/109. There were 21 WBS- Tg+ and 16 WBS+ Tg- patients. CONCLUSIONS: Investigation of the variables associated with successful ablation yields different results depending on the definition of success. There was a significant incidence of WBS+ Tg- cases after initial ablation. Until it is firmly established that such patients have a benign course both monitoring methods should be used.