[Interventional procedures for hepatic metastases]

Diagnostic accuracy of MR imaging to identify and characterize focal liver lesions: comparison between gadolinium and superparamagnetic iron oxide contrast media

To compare the diagnostic value of gadolinium (Gd) and ultrasmall superparamagnetic iron oxide (SPIO) contrast media for characterization of focal liver lesions (FLL), we retrospectively evaluated the results of magnetic resonance (MR) imaging in 68 patients (40 M, 28 F, age from 22 to 81 yrs) of which 36 with diagnosis of colo-rectal cancer, 26 with hepatic cirrhosis and 6 with incidental imaging detection of FLL. MR (Gyroscan Intera 1.5 T, Philips Medical Systems) study was performed using T1 and T2 fast-field-echo (FFE) and T2 turbo-spin-echo (TSE) sequences in axial and coronal views. Dynamic multi-phases gadolinium Gd-enhanced T1-FFE-Bh images were obtained in arterial, portal and equilibrium phases, followed by SPIO-enhanced T2-FFE scans. A qualitative analysis of pre- and post-contrast MR images to classify FLL as benign or malignant was performed using a 3-point scoring system: 0= benign; 1= suspicious for malignancy; 2= malignant. A total of 118 lesions were evaluated. In particular, histology (n=18), cytology (n=14) or clinical-imaging follow-up data (n=86) demonstrated 4 adenomas, 29 cysts, 3 focal steatosis, 25 hemangiomas, 1 focal vascular abnormality, 5 fibrotic lesions as well as 13 regenerative nodules, 6 dysplastic, 14 hepatocellular carcinomas (HCC), 17 metastasis and 1 cholangiocarcinoma. For MR imaging, diagnostic accuracy, sensitivity, specificity, positive (PPV) and negative (NPV) predictive values of Gd vs. SPIO images were respectively 83% vs. 92%, 79% vs. 74%, 85% vs. 99% (P=0.002), 68% vs. 96% (P=0.005) and 91% vs. 90%, respectively. The results suggest that SPIO-MR provides a diagnostic incremental value, as specificity and PPV, particularly to characterize FLL compared to Gd-MR; thus, we strongly recommend the use of SPIO when liver lesion characterization is requested and Gd images are uncertain.

Detection of recurrences during follow-up after liver surgery for colorectal metastases: both carcinoembryonic antigen (CEA) and imaging are important

BACKGROUND

The follow-up of patients treated for colorectal liver metastases (CRLM) is not standardized. The accuracy of an increase in carcinoembryonic antigen (CEA) levels for finding recurrences after treatment for CRLM is compared in this retrospective cohort study with the accuracy of routine imaging modalities of liver and chest.

METHODS

Data from all patients in follow-up after intentionally curative treatment for CRLM from 1990 to 2010 were analyzed. All patients underwent the same follow-up schedule. The way in which recurrences became apparent (i.e., CEA increase, routine imaging, or both) was registered. The specificity and sensitivity of increases in CEA before finding recurrent disease were calculated by receiver operating characteristic (ROC) curves. An economic evaluation of the cost per resectable tumor recurrence was performed.

RESULTS

ROC curves showed that a significant CEA increase was defined as a 25 % increase from the previous value. Recurrences were detected in 46 % of the procedures through CEA increase concomitant with positive imaging, in 23 % through CEA increase without positive findings on routine imaging, and in 31 % through positive imaging without an increase in CEA. The resectability of recurrences did not differ between triggers. Cost per curable recurrence was <euro>2,196 for recurrences found via CEA alone and <euro>6,721 for recurrences found with imaging and CEA.

CONCLUSIONS

In the follow-up of patients after liver surgery for CRLM, a 25 % increase in CEA serum level can accurately detect recurrences, but routine imaging is indispensable. In patients with CRLM, we advocate both CEA monitoring and imaging in the follow-up after liver surgery.

Thermal ablation of unresectable liver tumors: factors associated with partial ablation and the impact on long-term survival

Background

Thermal ablation procedures, including radiofrequency ablation (RFA) or laser-induced interstitial thermotherapy (LITT), are now well established in the treatment of malignant unresectable hepatic tumors. But the impact of partial ablation (PA) on long-term survival following computed tomography (CT)-guided radiofrequency ablation and laser- induced interstitial thermotherapy of unresectable malignant liver lesions and the associated risk factors of PA remain partially unknown.

Material/Methods

This study included 254 liver tumors in 91 consecutive patients (66 men and 25 women; age 60.9±10.4 years; mean tumor size 25±14 mm [range 5–70 mm]) who underwent thermal ablation (RFA or LITT) between January 2000 and December 2007. Mean follow-up period was 21.1 month (range 1–69 months). Survival rate and local progression-free survival (PFS) were calculated for patients with complete ablation (CA) vs. patients with partial ablation (PA) to assess the impact on long-term survival.

Results

Median survival after CA was 47 months compared to 25 months after PA (P=0.04). The corresponding 5-year survival rates were 44% vs. 20%. Median PFS for CA was 11 months compared to 7 months for PA (P=0.118). The sole statistically significant risk factor for PA was tumor size (>30 mm; P=0.0003). Sustained complete ablation was achieved in 71% of lesions ≤30 mm vs. 47% of lesions >30 mm.

Conclusions

We conclude that achievement of complete ablation is a highly important predictor of long-term survival and that tumor size is by far the most important predictor of the likelihood of achieving complete ablation.

Advances in research of microspheres containing Chinese medicine for interventional cancer therapy

Drug-loaded microspheres represent a newly developed particulate drug delivery system that possesses the characteristics of controlled release and targeting delivery. The use of microsphere agents in Chinese medicine can make up for the deficiency of traditional preparations, improve bioavailability, and decrease use dosage and non-target toxicity, so it have controlled release and targeting characteristics. Therefore, the research on microsphere agents has become a hot topic in the development of new delivery system for Chinese medicine. In this paper, we will review the biological characteristics of microsphere agents and discuss the recent advances and problems encountered in the research of microsphere agents.