RESUMEN

The purpose of the hypothesis testing is to determine that apparent diffusion coefficient (ADC) as an early biomarker can predict the metastatic lymph nodes' (LNs) response to neoadjuvant chemotherapy in advanced gastric cancer (GC) in early stage. From March 2011 to June 2015, 106 patients with advanced GC were enrolled in the study. Patients underwent conventional magnetic resonance imaging and functional diffusion weighted imaging before and 3 days, 7 days, 30 days, and 60 days following the standard chemotherapy. After surgery, among 3034 detected LNs, the positive group was divided into complete response (CR) group, partial response (PR) group, and stable disease (SD) group in accordance to the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Mean ADCs, short/long diameters of LNs before chemotherapy between the whole positive and the negative LNs were compared by t test. Changes of mean ADCs in 3 groups were analyzed by 1-way ANOVA. The mean ADC of the whole positive LNs was (1.145 ±â€Š0.014) × 10⁻³ mm²/s, which was significantly lower than that of the whole negative LNs ([1.491 ±â€Š0.010] × 10⁻³ mm²/s; P < 0.05). The means of both short/long diameters in the whole positive LNs were significantly longer than those in the whole negative LNs (P < 0.05). In CR, PR, and SD groups, the mean ADC of metastatic LNs on the 3rd day, 7th day, 13th day, and 16th day following the chemotherapy were all higher than that of LNs before chemotherapy, respectively (all P < 0.05). In addition, significant difference was found between mean ADCs in any 2 time points (all P < 0.05), except between mean ADCs in the 3rd day and in the 7th day of the chemotherapy. In conclusion, ADC can be used as an early biomarker to predict the metastatic LNs' response to neoadjuvant chemotherapy in advanced GC in early stage.

Asunto(s)

Quimioterapia Adyuvante/métodos , Imagen de Difusión por Resonancia Magnética/métodos , Metástasis Linfática/patología , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/patología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Índice de Severidad de la Enfermedad

RESUMEN

The aim of the study was to investigate the value of computed tomography (CT), magnetic resonance imaging (MRI) and diffusion weighted imaging (DWI) for diagnosing lymph nodes metastasis before treatment in gastric cancer. Eighty-two patients with proven gastric cancer underwent CT, morphological MRI (T2WI) and DWI examinations. Two radiologists independently assessed these images for the presence of lymph nodes involvement. Pathologic findings were considered as "gold standard". Independent samples t-test was used for the comparisons of short diameters and ADC values between the positive lymph nodes and the negative lymph nodes. Diagnostic accuracy of these three imaging modalities was evaluated by area under the receiver operating characteristics (ROC) curve (AUC). The ADC value of the positive lymph nodes was (1.15 ± 0.01) × 10-3 mm2/s, which was significantly lower than that of the negative lymph nodes (1.48 ± 0.01) × 10-3 mm2/s (t = 18.70, P < 0.0001). The short diameter of the positive lymph nodes (1.54 ± 0.38 cm) was significantly greater than that of the negative lymph nodes (0.95 ± 0.12 mm) (t = 19.03, P < 0.001). The AUC for all imaging modalities combined (0.893) was significantly larger than that for each imaging modality alone (P < 0.05), and the AUC of DWI (0.797) was significantly larger than (P < 0.05) that of morphological MRI (0.733). There was no statistically significant difference between the AUCs of CT and morphological MRI (P = 0.462). In conclusion, CT, MRI and DWI combined present significantly higher accuracy than each imaging modality alone in the detection of lymph nodes involvement.