Liver cancer imaging: the need for accurate detection of intrahepatic disease spread

A photo-responsive membrane for tailored drug delivery with spatially and temporally controlled release

Accurate delivery of therapeutics to tumor regions and effective sparing of normal tissue structures are important principles for the treatment of widespread metastases or malignant lesions in close proximity to vital organs. However, the currently available drug delivery techniques do not support precise drug release within the identified disease margins. We propose a tailored drug delivery strategy that utilizes a photo-responsive material in combination with tumor margin imaging for automated and tailored release of therapeutics. As a proof of concept, a poly(ethylene oxide)-b-PSPA (PEO-b-PSPA) diblock copolymer is synthesized by spiropyran (SP) polymerization. A photo-responsive membrane (PRM) is formed and irradiated with light sources of different wavelengths. Switching irradiation between ultraviolet light (UV) and green light (Vis) controls the permeability of the PRM in coincidence with the programmed irradiation patterns. The dynamic process of photo-switchable drug permeation through the PRM is modeled and compared with the experimental results. The strategy of tailored drug release is verified using both regular geometric shapes and metastatic cancer images. The therapeutic effect of this tailored drug release strategy is demonstrated in vitro in human breast cancer cells. Our pilot study implies the technical potential of using photo-responsive carriers for image-guided chemotherapy with precisely controlled drug release patterns.

Value of contrast-enhanced ultrasound (CEUS) in Focal Liver Lesions (FLL) with inconclusive findings on cross-sectional imaging

BACKGROUND

Contrast-enhanced ultrasound (CEUS) has been used as an additional imaging technique in order to evaluate focal liver lesions. CEUS is easy and fast to perform, overcomes the limitations of B-mode US.

OBJECTIVE

To evaluate the diagnostic potential of contrast-enhanced ultrasound (CEUS) in focal liver lesions (FLL) with unclear findings on computed tomography (CT) or magnetic resonance imaging (MRI).

METHODS

In this single-center retrospective study, 146 patients with at least one FLL underwent additional CEUS of the liver to clarify inconclusive cross-sectional imaging findings. Ultrasonography was performed using B-mode imaging and CEUS after injection of sulphur hexafluoride microbubbles (second-generation contrast agent) within two months after ceMRI or ceCT and interpreted by an experienced radiologist (EFSUMB level 3). Histopathological reports, long-term follow-up or clinical course served as reference standard.

RESULTS

Thirty-eight of the 146 patients had malignant and 108 benign FLL. Overall, CEUS had 92% sensitivity (95% -CI, 79-97) and 98% specificity (95% -CI, 93-99) with an AUC of 0.95 in correctly characterizing the lesion as malignant or benign. Sensitivity increased to 98% (95% -CI, 96-100) for benign lesions and decreased to 92% (95% -CI, 78-98) for malignant lesions. CEUS showed the highest diagnostical accuracy in lesion <1 cm with an AUC of 1.000, while the lowest accuracy was achieved in lesions >2 cm with an AUC of 0.924 due to a decreasing specificity of 86% (95% -CI, 87-100).

CONCLUSION

CEUS correctly distinguished malignant from benign FLL in cases with inconclusive cross-sectional imaging findings and achieved high levels of diagnostic accuracy. CEUS has added diagnostic value especially in small lesions ≤1 cm while specificity remains limited in larger lesions.

The role of echo-laparoscopy in abdominal surgery: five years' experience in a dedicated center

BACKGROUND

For more than 20 years intraoperative ultrasonography (IOUS) has been considered an important diagnostic tool in abdominal surgery. In the last few years, with the spread of laparoscopic surgery, echo-laparoscopy (LIOUS) has gradually replaced open ultrasonography, aiming to achieve similar results.

METHODS

LIOUS was performed using an ALOKA 5.500 device, provided with a linear flexible laparoscopic probe that was compatible with a 10-mm port. IOUS was performed by means of a linear side-view, T-shaped or microconvex probe. The probes were sterilized with hydrogen peroxide. No water bath was used during the surgical examination, but full contact of the probe with the surface of the involved organ was always attempted. From 2001 to 2005, 36 liver resections, 40 pancreas procedures, 203 procedures for suspected common bile duct calculi, 541 colon and 82 stomach resections, and 82 adrenal surgery procedures were performed. IOUS or LIOUS was performed in 432 patients (43.8%). All livers and pancreases underwent intraoperative ultrasound, while biliary, colonic, gastric, and adrenal pathologies were selectively studied when there were doubts about the location and extension of the disease.

RESULTS

IOUS and LIOUS were valuable diagnostic procedures, supplying relevant clinical information in 65.1% of the patients and modifying the surgical approach in 17.2%. LIOUS was used instead of cholangiography to study bile ducts when lythiasis was suspected, achieving high diagnostic specificity (98%) and accuracy (100%). Surgical anatomy of the bile ducts was correctly identified by LIOUS in every case.

DISCUSSION

In our experience IOUS and LIOUS were of the utmost importance in better defining staging of disease, infiltration of neighboring structures, number and size of nodular lesions, and anatomy of the hepatic pedicle and intrahepatic structures, thus making it possible to more accurately plan surgical procedures.

Radiofrequency ablation permits an effective treatment for colorectal liver metastasis

BACKGROUND

Radiofrequency ablation (RFA) has become an important adjunct to modern liver surgery. However, scant knowledge on long-term outcome of RFA for colorectal liver metastasis is available, nowadays.

METHODS

This is a prospective clinical study of patients with liver metastasis of colorectal cancer who were treated by RFA between April 1, 1998, and November 30, 2004. Forty-seven patients with 147 liver metastases were treated with RFA in a total of 70 interventions. A metastasis resection was not feasible in 80% of the interventions. All the patients were followed up at regular intervals with contrast-enhanced computed tomography (CT) and laboratory tests including carcinoembryonic antigen (CEA).

RESULTS

No RFA-related mortality occurred. The median follow-up time after the diagnosis of liver metastasis was 33 months. The RFA-related morbidity was 7%. After the RFA, the expected median overall survival rate is, to date, 39 months. Overall survival rates at 1, 2 and 3 years were 88%, 80% and 57%, respectively. Local recurrence rates reached 8.8% overall and 1.6% for metastasis smaller than 3cm in diameter. No local recurrence occurred for metastasis smaller than 3cm in diameter if treated with the newest RFA device.

CONCLUSIONS

Excellent local tumour control was achieved with radiofrequency ablation of small liver metastasis. The expected overall survival rate of patients with RFA for unresectable or non-resected colorectal liver metastasis improved in comparison with the survival rate reported following the natural course (best supportive care) or chemotherapy. The low local recurrence rate of metastases of less than 3cm challenges the results obtained by the more invasive treatment of conventional liver surgery.

MRI for Detection of Hepatocellular Carcinoma: Comparison of Mangafodipir Trisodium and Gadopentetate Dimeglumine Contrast Agents

OBJECTIVE

The purpose of our study was to compare the performance of mangafodipir trisodium (Mn-DPDP)-enhanced and dynamic gadopentetate dimeglumine-enhanced MRI for the detection of hepatocellular carcinoma.

MATERIALS AND METHODS

Forty-six patients with 96 hepatocellular carcinomas underwent Mn-DPDP- and gadopentetate dimeglumine-enhanced MRI. The MRI examination included unenhanced T2-weighted turbo spin-echo and T1-weighted 2D fast low-angle shot (FLASH) sequences and a 3D FLASH sequence after the administration of gadopentetate dimeglumine and Mn-DPDP. Two observers reviewed three sets of images: a set of gadopentetate dimeglumine-enhanced MR images, a set of Mn-DPDP-enhanced MR images, and a combination of the gadopentetate dimeglumine and Mn-DPDP sets. Using receiver operating characteristic (ROC) analysis, imaging sets were compared for diagnostic accuracy and sensitivity.

RESULTS

The area under the ROC curve (A(z)) was 0.942 for the gadopentetate dimeglumine-Mn-DPDP set, 0.932 for the gadopentetate dimeglumine set, and 0.877 for the Mn-DPDP set (p < 0.05). The mean sensitivity was greater for the gadopentetate dimeglumine set than for the Mn-DPDP set (87.5% vs 72.4%; p < 0.05). The false-negative rate of the Mn-DPDP set was statistically greater than that of the gadopentetate dimeglumine set (27.6% vs 12.5%). Most false-negative cases in the Mn-DPDP set were due to small (diameter < 2 cm), isoenhanced lesions.

CONCLUSION

Gadopentetate dimeglumine-enhanced MRI was superior to Mn-DPDP-enhanced MRI for the detection of hepatocellular carcinomas.

Liver cancer imaging: role of CT, MRI, US and PET

Liver imaging in patients with a history of known or suspected malignancy is important because the liver is a common site of metastatic spread, especially tumours from the colon, lung, pancreas and stomach, and in patients with chronic liver disease who are at risk for developing hepatocellular carcinoma. Since benign liver lesions are common, liver-imaging strategies should incorporate liver lesion detection and characterisation. Survey examination in patients with a known extra-hepatic malignancy to exclude the presence of hepatic and extra-hepatic involvement is normally undertaken with a contrast-enhanced computed tomography examination. When patients with hepatic metastases are being considered for metastasesectomy, they undergo a staging examination with contrast-enhanced magnetic resonance imaging (MRI) using tissue-specific contrast agents. Patients with chronic liver disease who are at risk for hepatocellular carcinoma undergo periodic liver screening for focal liver detection, usually with ultrasonography (US) with MRI being used when US is equivocal. Finally, contrast-enhanced MRI with extra-cellular gadolinium chelates is preferred for characterisation of indeterminate hepatic masses with liver biopsy used when tissue diagnosis is needed.

Pulse-inversion harmonic imaging improves lesion conspicuity during US-guided biopsy

PURPOSE

To assess the feasibility of percutaneous biopsy of low-conspicuity focal liver lesions with use of pulse-inversion harmonic imaging (PIHI) guidance in the late phase after injection of microbubble contrast agent.

MATERIALS AND METHODS

Twelve patients referred for ultrasound (US)-guided biopsy had liver lesions lacking adequate conspicuity to undergo biopsy under conventional ultrasound (US) guidance. They underwent biopsy procedures performed with the use of PIHI guidance in the late phase after injection of Levovist. The conspicuity of lesions, procedure time, number of passes, and success and complication rates were documented and compared to a control group. The control group consisted of retrospective analysis of 19 patients who had undergone conventional US-guided biopsy procedures performed by the same radiologist.

RESULTS

After contrast material injection, all lesions had sufficient increases in conspicuity to be targeted under PIHI guidance. Procedure time was prolonged in the PIHI group (66 minutes; range, 30-120 min; vs control, 33 min; range, 15-77 min; P <.01, Wilcoxon signed-rank test). The number of passes was greater in the PIHI group (1.9 +/- 0.3; vs control, 1.4 +/- 0.6; P <.01, chi(2) test). No statistically significant difference was observed when comparing success and complication rates.

CONCLUSION

PIHI in the late phase after injection of Levovist generated clear delineation of focal liver lesions in all cases, allowing an accurate and safe sampling. This technique broadens the scope of US-guided biopsy to lesions lacking adequate conspicuity on conventional US.

Radiofrequency ablation of hepatic tumors

Radiofrequency thermal ablation is receiving increasing attention as an alternative to standard surgical therapies for the treatment of liver neoplasms. Benefits over surgical resection include the anticipated reduction in morbidity and mortality, low cost, suitability for real time image guidance, the ability to perform ablative procedures on outpatients, and the potential application in a wider spectrum of patients, including nonsurgical candidates. This review examines reported clinical results of this new therapeutic technique, potential complications, current limitations, thermal ablation mechanisms, as well as technical features and diagnostic modalities used in the procedure.

Hepatocellular carcinoma: detection with gadolinium- and ferumoxides-enhanced MR imaging of the liver

PURPOSE

To test the hypothesis that the accuracy of gadolinium- and ferumoxides-enhanced magnetic resonance (MR) imaging is different in small (< or =1.5-cm) and large (>1.5-cm) hepatocellular carcinomas (HCCs).

MATERIALS AND METHODS

Forty-three consecutive patients with chronic liver disease were enrolled in this study. The imaging protocol included unenhanced breath-hold T1-weighted fast field-echo sequences, unenhanced respiratory-triggered T2-weighted turbo spin-echo (SE) sequences, dynamic gadolinium-enhanced T1-weighted three-dimensional turbo field-echo sequences, and ferumoxides-enhanced T2-weighted turbo SE sequences. Images of each sequence and two sets of sequences (ferumoxides set and gadolinium set) were reviewed by four observers. The ferumoxides set included unenhanced T1- and T2-weighted images and ferumoxides-enhanced T2-weighted turbo SE MR images. The gadolinium set included unenhanced T1- and T2-weighted images and dynamic gadolinium-enhanced three-dimensional turbo field-echo MR images. In receiver operating characteristic (ROC) curve analysis, the sensitivity and accuracy of the sequences were compared in regard to the detection of all, small, and large HCCs.

RESULTS

Imaging performance was different with gadolinium- and ferumoxides-enhanced images in the detection of small and large HCCs. For detection of small HCCs, the sensitivity and accuracy with unenhanced and gadolinium-enhanced imaging (gadolinium set) were significantly (P =.017) superior to those with unenhanced and ferumoxides-enhanced imaging (ferumoxides set). The area under the composite ROC curves, or A(z), for the gadolinium set and the ferumoxides set was 0.97 and 0.81, respectively. For large HCC, the ferumoxides set was superior compared with the gadolinium set, but this difference was not statistically significant. Analysis of all HCCs demonstrated no significant differences for gadolinium- and ferumoxides-enhanced imaging.

CONCLUSION

For the detection of early HCC, gadolinium-enhanced MR imaging is preferred to ferumoxides-enhanced MR imaging because the former demonstrated significantly greater accuracy in the detection of small HCCs.

Impact of multidetector CT hepatic arteriography on the planning of chemoembolization treatment of hepatocellular carcinoma

OBJECTIVES

We examined the impact of the increased sensitivity for hypervascular masses of multidetector CT hepatic arteriography on treatment decisions involving selective chemoembolization of hepatocellular carcinomas.

SUBJECTS AND METHODS

Thirty patients were referred for chemoembolization of unresectable hepatocellular carcinoma. Initial selective chemoembolization plans were formulated on the basis of diagnostic biphasic CT or MR imaging. Ultrafast CT hepatic arteriography was performed using a multidetector CT scanner and selective contrast material injection into the hepatic artery. The entire liver was scanned in a single breath-hold of approximately 20 sec with a slice thickness of 1 mm. Lesions and their arterial supplies were identified, and these data were immediately used to formulate a final plan for chemoembolization.

RESULTS

Hypervascular masses were detected in 29 patients. In 16 (53%) of the patients, preprocedural CT or MR imaging underestimated the number of lesions. In nine (30%) of these 16 patients, the additional lesions were detected only on CT hepatic arteriography, not on conventional angiography. CT hepatic arteriography findings had a major impact on planning the way in which chemoembolization treatment was performed. In three of the nine patients, the previously undetected lesions were treated with additional superselective chemoembolization. In the other six patients, chemoembolization was performed less selectively than originally planned.

CONCLUSION

Primarily because of the high sensitivity of multidetector CT hepatic arteriography in revealing small and multifocal hepatomas, findings of this modality frequently alter treatment plans involving selective administration of chemoembolic material.

Laparoscopy with laparoscopic ultrasound for pretreatment staging of hepatocellular carcinoma: a prospective study

Laparoscopy with laparoscopic ultrasound (L-LUS) has proved to be superior to conventional CT imaging in the staging of hepatocellular carcinoma (HCC). The aim of our prospective study was to evaluate the efficacy of L-LUS as compared with currently available imaging techniques (spiral CT or Lipiodol CT) in patients with HCC and liver cirrhosis. From January 1998 to May 2000, 70 consecutive patients (50 men and 20 women; mean age 67 +/- 7 years) were enrolled. Liver cirrhosis was related to chronic hepatitis C virus infection in 55, hepatitis B virus infection in seven, and alcohol abuse in eight patients. Preoperative diagnostic workup included the following: 70 ultrasound examinations of the liver, 23 CT scans after Lipiodol arteriography, and 53 spiral CT scans. A single lesion was found in 39 patients, two lesions in 20 patients, and three lesions in 11 patients. L-LUS was performed in all patients under general anesthesia using a two- to three-trocar technique. The examination was completed in 68 patients (97%); in two cases extensive adhesions prevented the L-LUS examination. L-LUS yielded additional information in 39 patients (57%). New histologically proved HCC lesions were detected in 14 patients (in the same liver segment in 4 cases and in different liver segments in 10 cases), and an adrenal metastasis was seen in one patient. In 23 patients, benign nodules were identified as regenerative macronodules, low-grade dysplastic nodules, or small hemangiomas. In 10 patients, correct localization of the primary lesion was detected by L-LUS in comparison with the preoperative liver location. In our experience, L-LUS is a safe and reliable procedure. It provides superior information (intraoperative histologic confirmation) for the diagnosis and pretreatment staging of HCC in patients with cirrhosis when compared with current radiologic imaging techniques.

Role of computerized tomography in the staging of gastrointestinal neoplasms

Gastrointestinal neoplasms are very common diseases, and the first challenge for clinicians is to define the extent of the tumor in order to plan the best treatment. The role of computerized tomography in assessing this kind of patient is well established worldwide. This article reviews the capabilities and the limits of this imaging technique in the staging of the tumors of the digestive tract (liver, gallbladder, biliary tract, pancreas, esophagus, stomach, small bowel, and colon).

Role of ultrasonography in the staging of gastrointestinal neoplasms

This article reviews the capabilities and limits of ultrasonography (US) in the staging of gastrointestinal neoplasms. US is a well-established tool in the investigation of abdominal diseases. Its role is very important in the first approach to liver, gallbladder, biliary, and pancreatic diseases, but its abilities for accurate staging may be limited by various factors, which will be discussed. In the evaluation of the stomach and intestine, US is rarely utilized, but it can occasionally demonstrate an unsuspected gastrointestinal mass that usually must be evaluated further with specific techniques (endoscopy and barium studies) to confirm the diagnosis and to perform an accurate staging (with endosonography and computed tomography).