Incidentally detected splenic lesions in ultrasound: does contrast-enhanced ultrasonography improve the differentiation of benign hemangioma/hamartoma from malignant lesions?

PURPOSE: The aim of the study was to identify and validate enhancing features for differentiating benign vascular neoplasms of the hemangioma/hamartoma type from malignant splenic lesions on contrast-enhanced ultrasonography (CEUS). MATERIALS AND METHODS: 136 splenic lesions (58 benign vascular neoplasms, 78 malignant) in 136 patients underwent baseline US and pulse-inversion CEUS after sulfur hexafluoride-filled microbubble injection. Two on-site readers assessed lesion enhancement features during arterial and parenchymal phase in consensus. Best predicting CEUS features for lesion diagnosis were identified through univariate and multivariate analyses. Two blinded off-site readers independently issued a confidence rating for lesion diagnosis in baseline US and CEUS using extracted diagnostic CEUS features. Diagnostic performance, receiver operating curves (Az-value), and interreader agreement were calculated. The reference standards were histopathology or CT and/or MR imaging with clinical follow-up.  RESULTS: Multivariate analysis outlined arterial hyperenhancement or isoenhancement to be an independent CEUS predictor of benign vascular neoplasms (odds ratio, 3.558; p < 0.0017). Within the subgroup of isoechoic or hypoechoic lesions, arterial hyperenhancement was virtually diagnostic for benign vascular neoplasm (odds ratio, 21.333; p < 0.001). The diagnostic accuracy and confidence (Az-value) of the two readers was 63.2 % and 70.6 % (0.785 and 0.818) for baseline US, which improved significantly to 87.5 % and 88.2 % (0.915 and 0.908) for CEUS (p < 0.001). Interreader agreement also increased with CEUS (қ = 0.88) compared to baseline US (қ = 0.52). CONCLUSION: Sulfur hexafluoride-enhanced CEUS improves differentiation between benign vascular and malignant splenic tumors and may be especially useful in clinical scenarios in which the incidental hypoechoic splenic lesion is unclear on conventional US.

Percutanous and intraoperative ultrasound-guided radiofrequency ablation of hepatic tumours.

PURPOSE: Ultrasonography (US)-guided Radiofrequency ablation (RFA) is increasingly used to treat liver tumours. The aim of this study was to evaluate the impact of multidisciplinary patient selection on clinical results. MATERIALS AND METHODS: From January 2002 to December 2004, 69 consecutive patients with malignant hepatic tumours were presented to our clinic for RFA-treatment. After a multidisciplinary tumour board decision, 33 patients (47.8%) with 70 liver tumours underwent RFA using a 14-gauge needle electrode via a percutaneous (26) or surgical (7) approach, either alone or combined with resection (3) or chemoembolisation (3). 36 patients (52.2%) were excluded from RFA treatment, mainly because of extensive disease or failure of prior chemotherapy. With a median of 20 months (range 6 - 42 months), all 69 patients were followed clinically to assess survival, and the 33 patients who received additional treatment were examined by contrast-enhanced CT to assess local success. RESULTS: Complete necrosis was obtained in 64/70 of ablated tumours (91.4%).The corresponding mean sizes (ranges) of lesion vs. necrosis achieved were 2.3 cm (0.9 - 5.0) vs. 3.7 cm (2.1 - 5.7). Two complications (6.6%) occurred, including one liver abscess and one postablational syndrome. At the time of the tumour board decision, the RFA (33) and non-RFA (36) group differed in mean sizes of tumours (2.3 vs. 3.5 cm), average tumours per patient (2.1 vs. 3.8), and failure of prior chemotherapy (2/33 vs. 22/36). From 36 patients judged to be ineligible for RFA, 24 (66.6%) underwent RFA at another institution. When comparing survival of patients who underwent RFA at our institution (33) vs. those who underwent RFA outside (24) vs. those who underwent no RFA (12), 1/33 (3%) vs. 9/24 (37.5%) vs. 8/12 (66.6%) died within 6 month and 27/33 (81.2%) vs. 5/24 (29.2%) vs. 2/12 (16.7%) were alive after 20 months median follow up. CONCLUSION: US-guided RFA offers a safe local treatment option to destroy small liver tumours (< 3 cm). Carefully and multidisciplinary selected patients may derive benefit, but uncritical application leads to unsatisfying clinical results.