Pattern of Retained Contrast on Immediate Postprocedure Computed tomography (CT) After Particle Embolization of Liver Tumors Predicts Subsequent Treatment Response

Abstract

Purpose To determine if the pattern of retained contrast on immediate postprocedure computed tomography (CT) after particle embolization of hepatic tumors predicts modified Response Evaluation Criteria in Solid Tumors (mRECIST) response. Materials and Methods This study was approved by the Institutional Review Board with a waiver of authorization. One hundred four liver tumors were embolized with spherical embolic agents (Embospheres, Bead Block, LC Bead) and polyvinyl alcohol. Noncontrast CT was performed immediately after embolization to assess contrast retention in the targeted tumors, and treatment response was assessed by mRECIST criteria on follow-up CT (average time 9.0 ± 7.7 weeks after embolization). Tumor contrast retention (TCR) was determined based on change in Hounsfield units (HUs) of the index tumors between the preprocedure and immediate postprocedure scans; vascular contrast retention (VCR) was rated; and defects in contrast retention (DCR) were also documented. The morphology of residual enhancing tumor on follow-up CT was described as partial, circumferential, or total. Association between TCR variables and tumor response were assessed using multivariate logistic regression. Results Of 104 hepatic tumors, 51 (49 %) tumors had complete response (CR) by mRECIST criteria; 23 (22.1 %) had partial response (PR); 21 (20.2 %) had stable disease (SD); and 9 (8.7 %) had progressive disease (PD). By multivariate analysis, TCR, VCR, and tumor size are independent predictors of CR (p = 0.02, 0.05, and 0.005 respectively). In 75 tumors, DCR was found to be an independent predictor of failure to achieve complete response (p <0.0001) by imaging criteria. Conclusion TCR, VCR, and DCR on immediate post-treatment CT are independent predictors of CR by mRECIST criteria.

Mapping Drug Dose Distribution on CT Images Following Transarterial Chemoembolization with Radiopaque Drug-Eluting Beads in a Rabbit Tumor Model

“…Reported prognostic indicators of tumor response rely on assessment of transient patterns of trapped soluble contrast material at immediate posttreatment imaging. Tumor response has been associated with the degree of soluble contrast material retention at the tumor periphery at immediate postprocedural conebeam CT following DEB-TACE, as well as residual tumor contrast enhancement at postprocedural noncontrast cone-beam CT (13)(14)(15)(16).…”

Lipiodol Uptake and Wash-out Rate Detection on Computed Tomography as Predictors for Tumor Recurrence in Hepatocellular Carcinoma Treated by Transcatheter Arterial Chemoembolization

“…For densities ≤ 390.03 HU of the measured ROI in the treated nodule at the baseline examination we can diagnose tumoral recurrence with a sensitivity of 84.62% and a specificity of 57.14%. Although slightly higher values have been obtained in larger studies (14), these values still seem low for a diagnostic test and therefore it may appear like an inappropriate parameter to use since other methods such as contrast uptake, or Magnetic Resonance Imaging apparently yield better results (15). Yet, we argue that if we choose a cut-off value of ≤ 545.36 HU, the sensitivity for diagnosing tumoral recurrence is 92.31%, albeit a specificity of only 28.57%.…”

Immediate Postablation 18F-FDG Injection and Corresponding SUV Are Surrogate Biomarkers of Local Tumor Progression After Thermal Ablation of Colorectal Carcinoma Liver Metastases

“…Local tumor progression remains a significant limitation of locoregional therapies such as ablation, especially compared with metastasectomy (8,10). Different approaches involving imaging and pathologic assessment for detecting residual disease after ablation have been explored (7)(8)(9)(10)(11)(12)(13)(14)(15). Biopsies performed immediately after ablation with pathologic and immunohistochemical assessments of the ablation zone showed a strong correlation between identification of viable tumor cells and local tumor progression (7).…”