Expected and Unexpected Imaging Findings after 90Y Transarterial Radioembolization for Liver Tumors.

Transarterial radioembolization (TARE), also called radioembolization or selective internal radiation therapy, is an interventional radiology technique used to treat primary liver tumors and liver metastases. The aim of this therapy is to deliver tumoricidal doses of radiation to liver tumors while selecting a safe radiation dose limit for nontumoral liver and lung tissue. Hence, correct treatment planning is essential to obtaining good results. However, this treatment invariably results in some degree of irradiation of normal liver parenchyma, inducing different radiologic findings that may affect follow-up image interpretation. When evaluating treatment response, the treated area size, tumor necrosis, devascularization, and changes seen at functional MRI must be taken into account. Unlike with other interventional procedures, with TARE, it can take several months for the tumor response to become evident. Ideally, responding lesions will show reduced size and decreased enhancement 3-6 months after treatment. In addition, during follow-up, there are many imaging findings related to the procedure itself (eg, peritumoral edema, inflammation, ring enhancement, hepatic fibrosis, and capsular retraction) that can make image interpretation and response evaluation difficult. Possible complications, either hepatic or extrahepatic, also can occur and include biliary injuries, hepatic abscess, radioembolization-induced liver disease, and radiation pneumonitis or dermatitis. A complete understanding of these possible posttreatment changes is essential for correct radiologic interpretations during the follow-up of patients who have undergone TARE. ©RSNA, 2019.

Valor pronóstico de la invasión vascular extramural por resonancia magnética en pacientes con cáncer de recto: cohorte retrospectiva / Prognostic value of extramural vascular invasion by magnetic resonance imaging in patients with rectal cancer: retrospective cohort

El objetivo fue evaluar si existe asociación entre la presencia del signo de invasión vascular extramural constatado por resonancia magnética (IVErm) con el período libre de enfermedad (PLE) a los 3 años, en pacientes con cáncer de recto (CR). Se realizó un estudio de cohorte retrospectiva. Se incluyeron 64 pacientes seguidos en nuestra institución con diagnóstico histológico de CR, evaluados inicialmente con RM, los cuales recibieron esquema de quimio-radioterapia neoadyuvante y cirugía curativa. Se analizó, mediante un análisis multivariable a través de una regresión de Cox, para ajustar por potenciales variables de confusión como la estadificación por tamaño tumoral (Trm) en la resonancia magnética (RM) basal, la asociación entre IVErm y el PLE a los tres años. Treinta pacientes (49.5%) sufrieron progresión o recaída, de los cuales 20 (60.6%) presentaron signos de IVErm. La presencia de IVErm se asoció con duplicación del riesgo de mala evolución (HR: 2.11; p = 0.054; IC: 1.00 - 4.51). Luego de ajustar por Trm esta tendencia se mantuvo. La presencia del signo IVErm se asocia con disminución del PLE a 3 años. Es mandatorio incorporarlo en los informes radiológicos a fin de contribuir al manejo de dicho grupo de pacientes (AU)

The aim was to evaluate whether there is an association between the presence of extramural vascular invasion sign found in the magnetic resonance (mrEMVI) and three years' disease-free survival (DFS) in patients with rectal cancer (RC). A retrospective cohort study was performed. Sixty four patients with proven RC, who had been initially evaluated with magnetic resonance (MR), had undergone neoadjuvant chemoradiotherapy and curative surgery, and had been followed for at least 3 years at our institution were included. Association between mrEMVI and reduced DFS was analyzed by logistic regression. Thirty patients (49.5 %) had reduced DFS, of whom 20 (60.6%) had signs of mrEMVI. The presence of mrEMVI duplicated the odds of reduced prognosis (HR: 2.11; 95% CI: 1.00 - 4.51; p < 0.054). The mrEMVI increases the likelihood of reduced DFS in patients with RC (AU)

[Magnetic resonance and extramural vascular invasion in patients with rectal cancer and liver metastases]. / Resonancia magnética e invasión vascular extramural en pacientes con cáncer rectal y metástasis hepaticas.

BACKGROUND: Extramural vascular invasion (EMVI) in patients with rectal cancer (RC) is associated with more locally advanced tumors, and independently predicts local and distant recurrence and poor overall survival. OBJETIVE: To determine the association between EMVI and synchronous liver metastases in patients with RC. METHODS: We performed a retrospective cohort study including patients with cancer of middle and lower rectum, which were evaluated with magnetic resonance (MRI) for initial staging in the period from January 2011 to January 2012 inclusive. All patients were evaluated with MRI for EMVI and were followed for a year to detect synchronous liver metastases by imaging methods (January 2012 to January 2013 inclusive). Multivariate analysis was performed by logistic regression. RESULTS: We included 68 patients. Twenty had liver metastases during the observation period (29.41%), of whom 15 had signs of MRI EMVI (75%). The incidence of synchronous liver metastases had a marginally significant association with the presence of EMVI (RR 3.35, 95% CI: 1.0001-11.2187, P = 0.050). CONCLUSION: The presence of MRI EVMI is a poor prognostic predictor factor of development of synchronous liver metastases in patients with RC.