Role of 18F-FDG-PET/CT in patients with differentiated thyroid cancer with biochemical incomplete or indeterminate response to treatment / Utilidad de la tomografía por emisión de positrones con 18F-FDG (18F-FDG PET/TC) en pacientes con carcinoma diferenciado de tiroides con respuesta bioquímica incompleta o indeterminada

OBJECTIVES: To assess the value of 18F-FDG-PET/CT for detecting recurrent/persistent disease in patients with biochemical incomplete (BIR) or indeterminate response (IR) and to assess the impact of 18F-FDG-PET/CT on the therapeutic management of these patients. METHODS: The study included patients with BIR, in whom 18F-FDG PET/CT was used within the diagnostic algorithm from our database. Patients with IR referred to our hospital with the 18F-FDG PET/CT already performed were also enrolled. All patients had neck ultrasonography with no structural changes. A change in therapeutic approach was defined as repeat surgery; administration of external beam radiotherapy; and/or the start of systemic therapy. RESULTS: Sixty patients (85% women) aged 18-86 years were enrolled in this retrospective study. Of these, 75% had BIR and 25% IR. Increased FDG uptake suggesting locoregional lesions was seen in 40% of patients. Sensitivity, specificity, and diagnostic accuracy of 18F-FDG PET/CT to detect local disease were 95%, 87.5% and 90% respectively. The therapeutic approach was modified in 50% of patients with locoregional lesions. CONCLUSIONS: Our study confirmed that 18F-FDG-PET/CT is a useful tool for detecting locoregional recurrence in thyroid cancer patients with BIR or IR with conflicting findings in standard diagnostic procedures. In 50% of patients with locoregional lesions, there was an immediate change in the treatment approach

OBJETIVOS: Evaluar la utilidad de la tomografía por emisión de positrones con 18F-FDG (18F-FDG PET/TC) para detectar enfermedad recurrente o persistente en pacientes con respuesta bioquímica incompleta (RBI) o respuesta indeterminada (RI), y evaluar el impacto de los resultados del PET/TC en el manejo terapéutico de estos pacientes. MÉTODOS: Se incluyeron pacientes con RBI, en los cuales el PET/TC fue utilizado en el algoritmo diagnóstico durante el seguimiento, y además pacientes con RI referidos a nuestro hospital con el estudio realizado. Todos los pacientes presentaban ecografía de cuello sin evidencia de alteraciones estructurales. Se consideró como cambio en el enfoque terapéutico a: 1) realización de nuevas cirugías, 2) administración de radioterapia externa, y/o 3) inicio de terapia sistémica. RESULTADOS: Sesenta pacientes con edad entre 16 a 86 años fueron incluidos retrospectivamente (85% mujeres), el 75% con RBI y el 25% con RI. En el 40% de los pacientes el PET/TC evidenciaron lesiones locorregionales. La sensibilidad, la especificidad y la precisión diagnóstica del PET/TC para detectar enfermedad locorregional fue del 95, 87,5 y 90%, respectivamente. En el 50% de los pacientes con enfermedad locorregional los resultados del PET/TC determinaron un cambio en la conducta terapéutica. CONCLUSIONES: Nuestro estudio demostró que el PET/TC es una herramienta útil en la detección de enfermedad locorregional recurrente o persistente en pacientes con cáncer de tiroides con RBI o RI durante el seguimiento con hallazgos contradictorios en los métodos diagnósticos estándares. En el 50% de los casos con lesiones locorregionales hubo un cambio inmediato en el enfoque terapéutico

Role of 18F-FDG-PET/CT in patients with differentiated thyroid cancer with biochemical incomplete or indeterminate response to treatment.

OBJECTIVES: To assess the value of 18F-FDG-PET/CT for detecting recurrent/persistent disease in patients with biochemical incomplete (BIR) or indeterminate response (IR) and to assess the impact of 18F-FDG-PET/CT on the therapeutic management of these patients. METHODS: The study included patients with BIR, in whom 18F-FDG PET/CT was used within the diagnostic algorithm from our database. Patients with IR referred to our hospital with the 18F-FDG PET/CT already performed were also enrolled. All patients had neck ultrasonography with no structural changes. A change in therapeutic approach was defined as repeat surgery; administration of external beam radiotherapy; and/or the start of systemic therapy. RESULTS: Sixty patients (85% women) aged 18-86 years were enrolled in this retrospective study. Of these, 75% had BIR and 25% IR. Increased FDG uptake suggesting locoregional lesions was seen in 40% of patients. Sensitivity, specificity, and diagnostic accuracy of 18F-FDG PET/CT to detect local disease were 95%, 87.5% and 90% respectively. The therapeutic approach was modified in 50% of patients with locoregional lesions. CONCLUSIONS: Our study confirmed that 18F-FDG-PET/CT is a useful tool for detecting locoregional recurrence in thyroid cancer patients with BIR or IR with conflicting findings in standard diagnostic procedures. In 50% of patients with locoregional lesions, there was an immediate change in the treatment approach.

The experience of an Endocrinology Division on the use of tyrosine multikinase inhibitor therapy in patients with radioiodine-resistant differentiated thyroid cancer.

PURPOSE: To describe the experience of our Division of Endocrinology with multikinase inhibitor (MKI) treatment in radioiodine-resistant differentiated thyroid cancer (DTC) patients. METHODS: Adults patients with a diagnosis of DTC treated with an MKI drug from March 2011 to October 2018 were registered into a retrospective database. Primary objectives were: the assessment of progression-free survival (PFS) and radiographic response evaluated according to RECIST v. 1.1. Adverse events (AEs) were evaluated by using Common Terminology Criteria for Adverse Events v. 5.0. RESULTS: Twenty-two patients were treated with MKIs (21 with sorafenib, one with lenvatinib as first-line treatment). Seven patients required a second-line therapy with lenvatinib and one patient required a third-line treatment with pazopanib. Median duration of treatment was 11.2 (4.8-79.6) months. Best responses with sorafenib were partial response (PR) in two patients (11%), stable disease (SD) >6 months in 13 patients (72%), and progressive disease (PD) in three patients (17%). Best responses with second-line lenvatinib were PR in one patient (33%) and SD in two patients (66%). Median PFS was 31.5 months. AEs were present in 19 (90%) patients under sorafenib. The most common AEs were hand-foot syndrome (HFS) (67%), diarrhea (52%), and hypertension (52%). Definitive withdrawal was necessary in only one patient (4.7%). CONCLUSIONS: Our study reflects the real-world clinical experience of an Endocrinology Division on the management of radioiodine-resistant DTC patients with sorafenib and lenvatinib, showing a beneficial therapeutic effect with acceptable tolerability.