CT-Guided Drainage of Fluid Collections Following Liver Resection: Technical and Clinical Outcome of 143 Patients during a 14-Year Period.

PURPOSE: To retrospectively evaluate the technical and clinical outcome of patients with symptomatic postoperative fluid collections following liver resection treated with CT-guided drainage (CTD). METHODS: 143 suitable patients were examined between 2004 and 2017. Technical success was defined as (a) sufficient drainage of the fluid collection and (b) the non-occurrence of peri-interventional complications requiring surgical treatment with minor or prolonged hospitalization. Clinical success was defined as (a) decreasing or normalization of specific blood parameters within 30 days after intervention and (b) no surgical revision in addition to intervention required. C-reactive protein (CRP), leukocytes and Total Serum Bilirubin (TSB) were assessed. Dose length product (DLP) for the intervention parts was determined. RESULTS: Technical success was achieved in 99.5% of 189 performed interventions. Clinical success was reached in 74% for CRP, in 86.7% for Leukocytes and in 62.1% for TSB. The median of successful decrease was 6.0 days for CRP, 3.5 days for Leukocytes and 5.5 days for TSB. In 90.2%, no surgical revision was necessary. Total DLP was significantly lower in the second half of the observation period (median 536.0 mGy*cm between years 2011 and 2017 vs. median 745.5 mGy*cm between years 2004 and 2010). CONCLUSIONS: Technical success rate of CTD was very high, and clinical success rate was fair to good. Reduction of the radiation dose reflects developments of CT technology and increased experience of the interventional radiologists.

Towards volumetric thresholds in RECIST 1.1: Therapeutic response assessment in hepatic metastases.

OBJECTIVES: To empirically determine thresholds for volumetric assessment of response and progress of liver metastases in line with the unidimensional RECIST thresholds. METHODS: Patients with metastatic colorectal cancer initially enrolled in a multicentre clinical phase-III trial were included. In all CT scans, the longest axial diameters and volumes of hepatic lesions were determined semi-automatically. The sum of diameters and volumes of 1, ≤2 and ≤5 metastases were compared to all previous examinations. Volumetric thresholds corresponding to RECIST 1.1 thresholds were predicted with loess-regression. In sensitivity analysis, the concordances of proposed thresholds, weight-maximizing thresholds and thresholds from loess-regression were compared. Classification concordance for measurements of ≤2 metastases was further analyzed. RESULTS: For measurements of ≤2 metastases, 348 patients with 629 metastases were included, resulting in 4,773 value pairs. Regression analysis yielded volumetric thresholds of -65.3% for a diameter change of -30%, and +64.6% for a diameter change of +20%. When comparing measurements of unidimensional RECIST assessment with volumetric measurements, there was a concordance of significant progress (≥+20% and ≥+65%) in 88.3% and of significant response (≤-30% and ≤-65%) in 85.0%. CONCLUSIONS: In patients with hepatic metastases, volumetric thresholds of +65% and -65% were yielded corresponding to RECIST thresholds of +20% and -30%. KEY POINTS: • Volumes and diameters of liver metastases from colorectal cancer were determined. • Volumetric thresholds of +65%/-65% corresponding to RECIST 1.1 are proposed. • Comparing both measurements, concordance was 88.3% (significant progress) and 85.0% (significant response).

Dynamic contrast-enhanced magnetic resonance imaging assessment of kidney function and renal masses: single slice versus whole organ/tumor.

OBJECTIVES: The aim of this study was to compare single-slice and 3-dimensional (3D) analysis for magnetic resonance renography (plasma flow [FP], plasma volume [VP], and glomerular filtration rate [GFR]) and for dynamic contrast-enhanced magnetic resonance imaging (MRI) of renal tumors (FP, VP, permeability-surface area product), respectively. MATERIAL AND METHODS: We prospectively included 22 patients (43 kidneys with 22 suspicious renal lesions) and performed preoperative and postoperative imaging before and after partial nephrectomy, respectively. Of the 22 renal lesions, 15 turned out to be renal cell carcinoma and were included in the tumor analysis, altogether leading to 86 renal and 15 tumor MRI scans, respectively. Dynamic contrast-enhanced MRI was performed with a time-resolved angiography with stochastic trajectories sequence (spatial resolution, 2.6 × 2.6 × 2.6 mm3; temporal resolution, 2.5 seconds) at 3 T (Magnetom Verio; Siemens Healthcare Sector) after injection of 0.05 mmol/kg body weight Gadobutrol (Bayer Healthcare Pharmaceuticals). Analysis was performed using regions of interest encompassing a single central slice and the whole kidney/tumor, respectively. A 2-compartment model yielding FP, VP, GFR, or tumor permeability-surface area product was used for kinetic modelling. Modelling was performed based on relative contrast enhancement to account for coil-related inhomogeneity. Significance in difference, agreement, and goodness of fit of the data to the curve was assessed with paired t tests, Bland-Altman plots, and χ2 test, respectively. RESULTS: Bland-Altman analysis revealed a good agreement between both types of measurement for kidneys and tumors, respectively. Results between single-slice and whole-kidney regions of interest showed significant differences for Fp (single slice, 256.1 ± 104.1 mL/100 mL/min; whole kidney, 217.2 ± 92.5 mL/100 mL/min; P < 0.01). Regarding VP and GFR, no significant differences were observed. The χ2 test showed a significantly better goodness of fit of the data to the curve for whole kidneys (0.30% ± 0.18%) than for single slices (0.43% ± 0.26%) (P < 0.01). In contrast to renal assessment, tumor analysis showed no significant differences regarding functional parameters and χ test, respectively. CONCLUSION: In dynamic contrast-enhanced MRI of the kidney, both 3D whole-organ/tumor and single-slice analyses provide roughly comparable values in functional analysis. However, 3D assessment is considerably more precise and should be preferred if available.