Revealing hepatic metastases from colorectal cancer: value of combined helical CT during arterial portography and CT hepatic arteriography with a unified CT and angiography system

Imaging in interventional oncology, the better you see, the better you treat

Imaging and image processing is the fundamental pillar of interventional oncology in which diagnostic, procedure planning, treatment and follow-up are sustained. Knowing all the possibilities that the different image modalities can offer is capital to select the most appropriate and accurate guidance for interventional procedures. Despite there is a wide variability in physicians preferences and availability of the different image modalities to guide interventional procedures, it is important to recognize the advantages and limitations for each of them. In this review, we aim to provide an overview of the most frequently used image guidance modalities for interventional procedures and its typical and future applications including angiography, computed tomography (CT) and spectral CT, magnetic resonance imaging, Ultrasound and the use of hybrid systems. Finally, we resume the possible role of artificial intelligence related to image in patient selection, treatment and follow-up.

Radiation Dose during Transarterial Radioembolization: A Dosimetric Comparison of Cone-Beam CT and Angio-CT Technologies

PURPOSE

To evaluate the radiation dose differences for intraprocedural computed tomography (CT) imaging between cone-beam CT and angio-CT acquired during transarterial radioembolization (TARE) therapies for hepatocellular carcinoma.

MATERIALS AND METHODS

A retrospective cohort of 22 patients who underwent 23 TARE procedures were selected. Patients were imaged in both cone-beam CT and angio-CT rooms as a part of their conventional treatment plan. Effective dose contributions from individual CT acquisitions as well as the cumulative dose contributions from procedural 3D imaging were evaluated. Angiography dose contributions were omitted. Cone-beam CT images were acquired on a C-arm Philips Allura system. Effective doses were evaluated by coupling previously published conversion factors (effective dose per dose-area product) to patient's dose-area product meter readings after the procedure. Angio-CT images were acquired on a hybrid Canon Infinix-i Aquilion PRIME system. Effective doses from angio-CT scans were estimated using Radimetrics. Comparisons of a single patient's dose differential between the 2 technologies were made.

RESULTS

The mean effective dose from a single CT scan was 6.42 mSv and 5.99 mSv in the cone-beam CT room and the angio-CT room, respectively (P = .3224), despite the greater field of view and average craniocaudal scan coverage in angio-CT. The mean effective dose summed across all CTs in a procedure was 12.89 mSv and 34.35 mSv in the cone-beam CT room and the angio-CT room, respectively (P = .0018).

CONCLUSIONS

The mean effective dose per CT scan is comparable between cone-beam CT and angio-CT when considered in direct comparison for a single patient.

Utilization of integrated angiography-CT interventional radiology suites at a tertiary cancer center

BACKGROUND

Integrated Angiography-Computed Tomography (ACT) suites were initially designed in the 1990's to perform complex procedures requiring high-resolution cross-sectional imaging and fluoroscopy. Since then, there have been technology developments and changes in patient management. The purpose of this study was to review the current usage patterns of a single center's integrated ACT suites.

METHODS

All procedures performed in 2017 in 3 ACT suites (InterACT Discovery RT, GE Healthcare) at a tertiary cancer center were reviewed retrospectively. Usage was classified as: Standard, in which the patient underwent a single procedure using either fluoroscopy, CT, or ultrasound (US); Combined, in which the patient underwent a single procedure utilizing both fluoroscopy and CT; or Staged, in which the patient underwent 2 separate but successive procedures using fluoroscopy and CT individually. The most frequently performed Combined and Staged procedures were further reviewed to determine how the different modalities were used. The duration of the most common Staged procedures was compared to analogous procedures' durations in single modality rooms over the period Jan 2016 to Sep 2019.

RESULTS

A total of 3591 procedures were performed on 2678 patients in the 3 ACT Suites. 80% of patients underwent a Standard procedure using fluoroscopy (38%), CT (32%) or US (10%) and accounted for 70% of the room occupation time. Fourteen and three percent of the patients underwent Combined or Staged procedures, occupying 19 and 5% of the room time, respectively. The remaining procedures were classified as both Combined and Staged, representing 3% of the patients and 6% of the room occupation time. The most common Combined procedures were drainages, hepatic arterial embolizations or radioembolizations, arterial, and biliary interventions. The most common Staged procedures were multiple drainages and hepatic arterial embolizations followed by biopsies or ablations. The room occupation time for liver tumor embolization and ablation was significantly shorter (p < 0.01) when performed in a Staged fashion versus the analogous procedures in single modality room.

CONCLUSION

An integrated ACT system provides the capability to perform complex Combined or Staged procedures as well as scheduling flexibility by allowing any type of case to be performed in the IR suite.

Radiation Exposure During Transarterial Chemoembolization: Angio-CT Versus Cone-Beam CT

INTRODUCTION

Cone-beam computed tomography (CBCT) has been developed to improve reliability of many interventional radiology (IR) procedures performed with Angio system, such as transarterial chemoembolization (TACE). Angio-CT has emerged as a new imaging technology that combines a CT scanner with an Angio system in the same IR suite. The purpose of our study was to compare Angio system with CBCT capability and Angio-CT in terms of patient radiation exposure during TACE procedures.

MATERIALS AND METHODS

Consecutive TACE procedures performed between January 2016 and September 2017 with the two imaging modalities (Artis Zeego defining the CBCT group and Infinix-i 4D-CT defining the Angio-CT group) were reviewed. TACE and patient's characteristics and patient radiation exposure parameters were collected. Dose-area products (DAP) and dose-length products (DLP) were converted into effective doses (ED) using conversion factors. Accuracy of tumor targeting and response was retrospectively assessed.

RESULTS

A total of 114 TACE procedures in 96 patients were included with 57 procedures in each group. The total ED in the Angio-CT group was 2.5 times lower than that in the CBCT group (median 15.4 vs. 39.2 mSv, p < 0.001). Both 2D ED and 3D ED were lower in the Angio-CT group than in the CBCT group (5.1 vs. 20 mSv, p < 0.001, and 7.4 vs. 17.9 mSv, p < 0.001, respectively). There was no significant difference neither in terms of classes of tumor targeting (p = 0.509) nor in terms of classes of tumor response (p = 0.070) between both groups.

CONCLUSION

Angio-CT provides significant decrease in patient effective dose during TACE procedures compared to Angio system with CBCT.

Selective balloon-occluded transarterial chemoembolization for patients with one or two hepatocellular carcinoma nodules: Retrospective comparison with conventional super-selective TACE

AIM

Selective balloon-occluded transarterial chemoembolization (B-TACE) enables strong TACE; infusion of more volume of lipiodol emulsion and forceful injection of embolization materials. The aim of this study is to analyze the efficacy of B-TACE for patients with one or two hepatocellular carcinoma (HCC) nodules compared with conventional super-selective TACE using a microcatheter (C-TACE).

METHODS

We retrospectively selected patients without previous history of TACE, with one or two HCC nodules, with performance status 0/1, and with liver function of Child-Pugh score A/B. Between 2008 and 2010, a 3-Fr microballoon catheter was used for targeted TACE (B-TACE group). Between 2005 and 2008, a 2-Fr microcatheter was used (C-TACE group). Control rates of primary nodule, overall survival rates and tumor-free rates in the liver were calculated for each group using the Kaplan-Meier method. Univariate analysis was performed to compare between the groups using the log-rank test. Multivariate analysis was performed for analysis of prognostic factors using Cox's proportional hazard model. The factors were B-TACE versus C-TACE, Child-Pugh score A versus B, single nodule versus double, large nodule versus small , elder versus not, and prior radiofrequency ablation treatment versus not.

RESULTS

Control rates of the primary nodule were improved by B-TACE. B-TACE was an independent factor to improve both control rates of the primary nodule and overall survival rates. Child-Pugh score A was an independent factor to increase overall survival rates. There was no statistically significant difference in overall survival or tumor-free survival rates between the groups.

CONCLUSION

B-TACE was an independent factor to improve overall survival rates on multivariate analysis, but there was no significant difference in overall survival rates between B-TACE and C-TACE groups on univariate analysis.

Accurate and rapid identification of feeding arteries with multidetector-row angiography-assisted computed tomography for transarterial chemoembolization for hepatocellular carcinoma

BACKGROUND

Transarterial chemoembolization (TACE) is an important treatment modality for hepatocellular carcinoma (HCC). Accurate identification of feeding arteries and catheterization are necessary for achieving treatment efficacy, especially with selective TACE. However, this often requires multiple imaging studies. We evaluated the utility of a newly developed apparatus that combines multidetector-row computed tomography (MDCT) and angiography (angio-MDCT) to facilitate TACE for treatment of HCC.

METHODS

A total of 73 patients who underwent selective TACE with angio-MDCT were compared with 57 patients who had undergone selective TACE with single-row computed tomography assisted by angiography (angio-CT) in terms of the number of imaging studies needed to complete TACE.

RESULTS

The mean number of digital subtraction arteriography (DSA) and CT studies required for characterization of feeding arteries before embolization was 3.53 (range 1-8) and 5.16 (range 2-11), respectively, with single-row angio-CT, and 1.67 (range 1-5) and 2.90 (range 1-5), respectively, with angio-MDCT. Fewer studies were needed in patients who underwent TACE with angio-MDCT (p < 0.0001 for both DSA and CT). Whereas single-row angio-CT failed to identify extrahepatic feeders in three patients (37.5%), all extrahepatic feeders could be identified with angio-MDCT.

CONCLUSIONS

Angio-MDCT facilitates rapid and accurate identification of feeding arteries in patients undergoing TACE through the three-dimensional image analyses by the reconstruction with the workstation.

Current role of hybrid CT/angiography system compared with C-arm cone beam CT for interventional oncology

Hybrid CT/angiography (angiography) system and C-arm cone beam CT provide cross-sectional imaging as an adjunct to angiography. Current interventional oncological procedures can be conducted precisely using these two technologies. In this article, several cases using a hybrid CT/angiography system are shown first, and then the advantages and disadvantages of the hybrid CT/angiography and C-arm cone beam CT are discussed with literature reviews.

Current status of imaging and emerging techniques to evaluate liver metastases from colorectal carcinoma

Colorectal cancer is the third most common cancer diagnosed in both men and women in the United States. Liver is a common site of tumor spread and in approximately 30% of the cases; synchronous liver disease is present at the time of diagnosis. Early detection of liver metastases is crucial to appropriately select patients who may benefit from hepatic resection among those needing chemotherapy, to improve 5-year survival. Advances in imaging techniques have contributed greatly to the management of these patients. Multidetector computed tomography is the most useful test for initial staging and in posttreatment surveillance settings. Magnetic resonance imaging is considered superior to multidetector computed tomography and positron emission tomography for the detection and characterization of small lesions and for liver evaluation in the presence of background fatty liver changes. Positron emission tomography-computed tomography has a problem-solving role in the detection of distant metastasis and in posttreatment evaluation. The advanced imaging methods also serve a role in selecting appropriate patients for radiologically targeted therapies and in monitoring response to conventional and novel therapies.

Risk of occult irresectable disease at liver resection for hepatic colorectal cancer metastases: a contemporary analysis

INTRODUCTION

Traditionally, rates of irresectable disease at laparotomy for colorectal liver metastases (CRLM) have ranged from 15 to 70%. Diagnostic laparoscopy has been shown to be effective at preventing nontherapeutic laparotomy in selected patients. The purpose of this study was to analyze the resectability rate and role of diagnostic laparoscopy in a contemporary cohort.

METHODS

Using a prospectively maintained database, we identified patients who were explored for presumed resectable CRLM. Clinical and pathologic data associated with the finding of irresectable disease were analyzed.

RESULTS

From 2008-2010, 455 patients were explored. Of these, 35 (7.7%) did not undergo a resection and/or ablation. Of the 35 patients with irresectable disease, 15 (43%) had disease limited to the liver, 17 (49%) had extrahepatic disease (EHD), and 3 (9%) had other reasons precluding resection. Of the whole cohort, 45 patients (9.9%) were found to have EHD, and 27 of these (60%) underwent complete resection or ablation. The only factor associated with irresectable disease was a prior history of EHD, which was present in 29% of those found irresectable versus 13% of those resected (p = 0.022). Diagnostic laparoscopy was performed in 55 patients. Four of these patients had irresectable disease, and three were spared unnecessary laparotomy. Therefore, the yield was 5% and the sensitivity 75%.

CONCLUSIONS

The finding of irresectable disease is a rare event with modern radiologic assessment and the expansion of indications for resection. Diagnostic laparoscopy has a low yield and should be considered if there is a history of EHD or suspicious findings on preoperative imaging.

Transarterial chemoembolization for hepatitis B virus-associated hepatocellular carcinoma: improved survival after concomitant treatment with nucleoside analogues

PURPOSE

To determine whether nucleoside analogue therapy is associated with improved survival in patients with hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) who are treated solely with transarterial chemoembolization.

MATERIALS AND METHODS

A retrospective chart review of patients diagnosed with HBV-associated HCC was performed to identify patients treated solely with chemoembolization. Relevant demographic and clinical data were extracted and recorded. The influence of therapy with nucleoside analogues (lamivudine, adefovir dipivoxil, or entecavir) was determined by estimating the survival function using the Kaplan-Meier product-limit method.

RESULTS

The inclusion criteria for chemoembolization were met by 81 patients (67 men and 14 women, mean age 60.6 years ± 9.2); 21 (25.9%) of these patients had been treated with nucleoside analogues. The number of chemoembolization treatments was significantly greater in the patients who were treated with nucleoside analogues (3.43 ± 2.32) than in the patients who did not receive nucleoside analogues (1.82 ± 0.95; P = .0022). The 1-year, 3-year, and 5-year survival rates were 89.5%, 66.8%, and 40.5% in the patients treated with nucleoside analogues and 72.6%, 27.5%, and 14.3% in the patients not treated with nucleoside analogues. The survival rate was significantly higher in the patients who received nucleoside analogues (P = .0051). Nucleoside analogue intake was an independent factor that was associated with increased survival (P = .0063).

CONCLUSIONS

Administration of nucleoside analogues was associated with longer survival in patients with HBV-associated HCC who were treated with transarterial chemoembolization.

Detection of liver metastases secondary to pancreatic cancer: utility of combined helical computed tomography during arterial portography with biphasic computed tomography-assisted hepatic arteriography

BACKGROUND

This study was designed to define the diagnostic advantage of computed tomography during arterial portography (CTAP) combined with computed tomography-assisted hepatic arteriography (CTHA) for the preoperative detection of liver metastases secondary to pancreatic cancer compared with that of multidetector computed tomography (MDCT).

METHODS

From January 2002 to December 2007, we retrospectively studied 197 consecutive patients with pancreatic cancer. MDCT was performed on 192 patients prior to preoperative visceral angiography; 153 patients underwent CTAP + CTHA at the time of preoperative angiography.

RESULTS

Liver metastases were identified in 39 patients by means of MDCT. Of the 153 patients who had no evidence of liver metastases on MDCT, 129 patients underwent CTAP + CTHA, and 53 of these 129 patients (41.1%) were diagnosed as having liver metastases that could not be detected by MDCT. These tumors missed by MDCT ranged from 3 to 15 mm in size. On CTAP + CTHA, a solitary nodule in the liver was detected in 11 patients, 2 nodules were detected in 6 patients, 3 lesions were detected in 2 patients, and ≧4 lesions were detected in 34 patients. The sensitivity and specificity of CTAP + CTHA versus MDCT were 94.2 versus 48.4% and 82.7 versus 97.9%, respectively.

CONCLUSIONS

The combination of CTAP and CTHA is useful to confirm liver metastases and can potentially offer more accurate staging of pancreatic cancer compared with MDCT.

Impact of a unified CT angiography system on outcome of patients with hepatocellular carcinoma

OBJECTIVE

The purpose of our study was to evaluate the impact of a unified CT angiography (CTA) system for the management of patients with hepatocellular carcinoma (HCC).

SUBJECTS AND METHODS

A total of 1,312 patients with HCC who had been diagnosed and treated between 1990 and 2003 were studied. The clinical characteristics and survival rate were compared between patients who underwent pretreatment evaluation of tumor progression by a unified CTA system and those who underwent evaluation by a conventional angiography system. In addition, the survival rates for 438 patients who underwent transcatheter arterial chemoembolization (TACE) as initial treatment were compared between patients who were treated using a unified CTA system and those who were treated without the system.

RESULTS

Overall, the survival rate was higher in patients who underwent pretreatment examination using a unified CTA system than in those who underwent examination without it (p < 0.0001). The survival rate was higher when focusing on patients with HCC of stage I (p = 0.0093). In patients who underwent TACE as an initial treatment, the survival rate was higher in patients treated by TACE using a unified CTA system than in those without it (p = 0.0023).

CONCLUSION

The more accurate and detailed pretreatment evaluation of HCC progression using a unified CTA system contributed to the improvement of survival of patients with HCC. In addition, it contributed to the improved efficacy of TACE with an increased survival rate.

Interval period tumor progression: does delayed hepatectomy detect occult metastases in synchronous colorectal liver metastases?

BACKGROUND

Rapid remnant liver recurrence in patients with synchronous colorectal liver metastases (CRLM) is occasionally experienced after simultaneous colorectal and liver resection. We evaluated the tumor progression during interval periods to determine whether delayed hepatic resection detects occult metastases.

METHODS

One hundred thirty-seven patients underwent hepatectomy for synchronous CRLM. Up to 2003, 116 patients underwent simultaneous colorectal and hepatic resection. From 2004 onward, we identified 21 patients undergoing delayed hepatectomy for synchronous CRLM. The tumor progression during interval was determined by a dynamic computed tomography scan.

RESULTS

Median/mean interval between the two evaluations prior to the first and second surgery was 2/2.4 months. The median/mean number of metastases detected at each evaluation was 2/3.3 and 3/4.6, respectively. Nine of the 21 (43%) patients had new detectable metastatic lesions after reevaluation. For 11 of the 21 patients, it was necessary to reconsider planned surgical procedure which was determined prior to colorectal surgery. Hepatic disease-free survival was significantly different between patients undergoing delayed and simultaneous hepatectomy. Multivariate analysis showed that the delayed hepatectomy was a significant independent prognostic factor in hepatic disease-free survival.

CONCLUSION

Tumor progression was recognized and occult metastases were detected after the interval reevaluation. Delayed hepatectomy may be a useful approach to reduce rapid remnant liver recurrence in synchronous CRLM.

Usefulness of cone-beam volume CT with flat panel detectors in conjunction with catheter angiography for transcatheter arterial embolization

PURPOSE

To assess the usefulness of cone-beam volume computed tomography (CT) (cone-beam CT) with use of flat panel detectors of the direct conversion type in conjunction with conventional digital subtraction angiography (DSA) in the diagnosis and treatment of patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Forty-nine consecutive patients (52 suspicious lesions) were prospectively examined. All patients underwent intraarterial rotational angiography with a flat panel detector system, and the cone-beam CT scans were reconstructed from the volume data set. The authors evaluated the diagnostic quality of cone-beam CT for the transcatheter arterial chemoembolization (TACE) procedure.

RESULTS

The diagnostic quality of conventional DSA plus cone-beam CT with regard to tumor staining was superior to that of DSA alone. Cone-beam CT showed tumor staining in five lesions that were difficult to diagnose with confidence on the basis of the DSA findings alone. The extent of contrast medium perfusion was sufficiently visualized on all cone-beam CT scans at the tip of the catheter positioned in either the segmental or subsegmental hepatic arteries. In 42 of the 52 lesions (81%), cone-beam CT provided additional useful information for therapeutic decision making or TACE compared with DSA.

CONCLUSIONS

Intraarterial cone-beam CT with a flat panel detector can provide clinically acceptable image quality in the assessment of HCC, thereby improving the detection of tumor staining due to HCC and the visualization of the extent of contrast medium perfusion.

A cone-beam volume CT using a 3D angiography system with a flat panel detector of direct conversion type: usefulness for superselective intra-arterial chemotherapy for head and neck tumors

BACKGROUND AND PURPOSE

The development of flat panel detectors (FPDs) has made cone-beam CT feasible for practical use in a clinical setting. Our purpose was to assess the usefulness of cone-beam CT using the FPD in conjunction with conventional digital subtraction angiography (DSA) for performing superselective intra-arterial chemotherapy for head and neck tumors.

MATERIALS AND METHODS

Twenty-three consecutive patients (43 feeding arteries) were prospectively examined. All of the patients underwent intra-arterial rotational angiography using an FPD system, and the cone-beam CT was reconstructed from the volume dataset. Two radiologists evaluated the quality of the cone-beam CT and then evaluated whether the additional information provided by the cone-beam CT was useful for the interventional procedures.

RESULTS

In 41 (95%) of 43 arteries, the extent of contrast material perfusion was sufficiently visualized on cone-beam CT. In 20 (47%) of 43 arteries, the DSA plus cone-beam CT was superior to the DSA alone regarding the precise understanding of vascular territory of each artery. This information was helpful for predicting the drug delivery for superselective intra-arterial chemotherapy, especially in deeply invasive tumors with multiple feeding arteries.

CONCLUSION

In superselective intra-arterial chemotherapy for head and neck tumors, cone-beam CT with FPD provides useful additional information, which allows interventional radiologists to determine the feeders, as well as the dose of antitumor agent for each feeder.

Detection of hepatic metastases from colorectal carcinoma: comparison of histopathologic features of anatomically resected liver with results of preoperative imaging

GOALS

The specificity and sensitivity of intravenous-enhanced multidetector row computed tomography (MDCT), superparamagnetic iron oxide-enhanced magnetic resonance imaging (SPIO-MRI), multidetector row computed tomography with arterioportography combined with multidetector row computed tomography with hepatic arteriography (CTAP/CTHA), and intraoperative ultrasonography (IOUS) for detecting hepatic metastases from colorectal carcinoma were evaluated based on histopathologic examination of resected livers.

STUDY

MDCT, SPIO-MRI, CTAP/CTHA, and IOUS were performed routinely to determine surgical indications and methods in patients with hepatic metastases from colorectal carcinoma. The resected liver specimens were then cut serially into sections 3 to 5 mm thick for routine histologic examination.

RESULTS

Fifty metastatic lesions were detected by histopathologic study of a large amount of anatomically resected liver from 8 patients with colorectal liver metastasis. The tumors ranged in size from 3 to 53 mm (mean 13.8 mm) and 26 lesions (52%) were less than 10 mm in diameter. Histopathologic examination of the resected liver specimens showed that CTAP/CTHA was the most sensitive imaging modality, followed in order by IOUS, SPIO-MRI, and MDCT. Among all the tumors detected by CTAP/CTHA, SPIO-MRI overlooked 5, but all of the tumors detected by SPIO-MRI were also detected by CTAP/CTHA. The number of metastatic liver tumors detected differed significantly among MDCT, SPIO-MRI, and histopathologic examination. One false-positive lesion was detected by IOUS.

CONCLUSIONS

CTAP/CTHA is a useful preoperative imaging modality for detecting small hepatic metastases from colorectal carcinoma.

Clinical impact of multidetector row computed tomography on patients with pancreatic cancer

OBJECTIVES

This study was designed to compare multidetector row computed tomography (MDCT) and CT-assisted hepatic arteriography (CTHA)/CT during arterial portography (CTAP)/angiography/contrast-enhanced CT (CECT) findings prospectively for accuracy in the detection of liver metastasis and vascular involvement of the tumor.

METHODS

The study included 43 patients with pancreatic cancer who were evaluated from September 2002 to December 2003. These patients underwent preoperative evaluation by angiography/CTHA/CTAP/CECT (7-mm thickness) and by MDCT (1.25-mm thickness).

RESULTS

The sensitivity, specificity, positive predictive value, and negative predictive value of liver metastasis diagnosis were all superior using MDCT relative to CTHA/CTAP. The diagnostic accuracy of liver metastasis for patients with tumors less than 10 mm in diameter was particularly superior with MDCT relative to CTHA/CTAP. The surgical and pathological findings of vascular involvement were more accurately diagnosed by MDCT than by CTHA/CTAP/angiography/CECT. Although MDCT findings were generally similar to surgical findings of vascular involvement, MDCT overestimated the incidence of pathological vascular involvement.

CONCLUSIONS

Multidetector row CT imaging can potentially offer more accurate staging of pancreatic cancer and may be useful to surgeons both in preoperative planning and for intraoperative guidance.

Power and sample size calculation of comparative diagnostic accuracy studies with multiple correlated test results

We consider the power and sample size calculation of diagnostic studies with normally distributed multiple correlated test results. We derive test statistics and obtain power and sample size formulas. The methods are illustrated using an example of comparison of CT and PET scanner for detecting extra-hepatic disease for colorectal cancer.

[Surgical treatment of gastric, enteric pancreatic endocrine tumors. Part 2. treatment of hepatic metastases]

The development of hepatic metastases (HM) marks a turning point in the evolutionand prognosis of well-differentiated endocrine tumors (ET). Management is usually multicisciplinary (chemotherapy, arterial chemo-embolization, percutaneous ablation, somatostatin analogs, biotherapy, and surgery). A thorough pre-operative work-up is neecessary to exclude extrahepatic disease and to detect tiny HM's. Complete resection (RO) is the only curative treatment for well-differentiated ET with HM. The type of resection is specific to each case and may range from wedge resection of a metastasis to complex hepatectomy with simultaneous resection of the primary ET. Cytoreductive surgery may be indicated for palliation when medical therapy fails to control endocrine symptoms. Operative mortality is low (0-6%) and global survival is 60-70% afterafter R) resection of HM of well-differentiated ET's. After resection of HM involving only one hepatic lobe, 5 year survival is better than 90%. When HM are multiple, bilobar and synchronous, the prognosis is very poor--only 10% of such patients can have a complete resection and this often requires a long prologue of ancillary procedures (chemotherapy, chemoembolization, portal vein ligation, percutaneous ablation). Hepatic transplantation (HT) has only a limited rôle in the treatment of HM for ET; mortality is high when HT is associated with large and complex resections, i.e. pancreaticoduodenectomy. Although there is no consensus in the literature, HT should be limited to the most optimal cases (young, good general health, well-differentiated tumor, slow evolution, complete resection of the primary rumor, and unresectable liver metastases). Global survival for HT in patients with ET is 60% at 2 years, 47% at 5 years; tumor-free survival at 5 years is 24%. HT for HM has better survival results for ET's of intestinal origin (carcinoids) than for duodenopancreatic ET's.

Determinants of unresectability and outcome of patients with occult colorectal hepatic metastases

BACKGROUND

Patients chosen for liver resection of colorectal liver metastases are a select group with minimal disease, favorable tumor biology and earlier presentation when compared to unresectable patients. Despite intense preoperative assessments, operative detection of occult unresectable disease is inevitable for a small group of patients. The aim of this study was to evaluate determinants of occult unresectability, and to establish if patients with occult unresectable disease demonstrate survival benefits similar to resected patients, or more similar to patients diagnosed with metastatic disease who were never explored.

METHODS

A retrospective medical record review was performed on 171 patients with colorectal hepatic metastases who underwent exploration with the intent of performing a curative liver resection. Patient and tumor characteristics, operative findings and survival were evaluated. Univariate and multivariate analysis were performed to evaluate determinants of unresectability, and survival was determined by Kaplan-Meier analysis.

RESULTS

One hundred forty-six patients were completely resected and 25 patients were found to have occult unresectable disease during exploration. Of these 25 patients, 10 had more extensive hepatic disease than expected which precluded resection, while 15 patients had unexpected extrahepatic disease. Of the 15 patients with extrahepatic disease, 7 had otherwise resectable liver metastases. Only bilobar disease was a statistically significant finding associated with occult unresectability on multivariate analysis (P = 0.05). Resected patients had a median survival of 37 months, while unresected patients had a median survival of 17 months (P < 0.005). At 3 and 5 years, the overall survival for resected patients was 52% and 29%. The survival at 3 years for patients with occult unresectable disease was only 5%, with no 5 year survivors.

CONCLUSIONS

The majority of patients with occult unresectable colorectal hepatic metastases had bilobar disease or extrahepatic spread. Despite the process of patient selection that leads to an attempt for curative resection, patients with occult unresectable disease identified at exploration suffer from poor survival that approximates the outcome of patients never considered for resection.

Malignant cystic and necrotic liver lesions: A pattern approach to discrimination

Malignant primary and metastatic lesions of the liver have a myriad of imaging appearances. Discriminating between the various lesions requires an understanding of the underlying pathophysiology and imaging characteristics that lead to their malignant appearances. A pattern approach of recognition by imaging with understanding of why particular lesions behave the way they do on sonography, CT, MRI, and nuclear scintigraphy can be developed. A broad selection of malignant cystic liver lesions will be displayed in a multimodality pictorial style including hepatocellular carcinoma, cholangiocarcinoma, cystic and necrotic hepatic metastases, biliary cystadenoma/cystadenocarcinoma, epitheloid hemangioendothelioma, hepatoblastoma, and cystic sarcomas. Characteristic imaging features, clinical symptoms, and prognosis will be discussed. Emphasis will be placed on consistent features of these malignant lesions that help to discriminate them from other hepatic disorders.

Preoperative detection of liver metastases secondary to pancreatic cancer: utility of combined helical computed tomography during arterial portography with biphasic computed tomography-assisted hepatic arteriography

OBJECTIVE

This study was designed to define the diagnostic advantage of computed tomography during arterial portography combined with computed tomography-assisted hepatic arteriography ( CTAP + CTHA) for preoperative detection of liver metastases secondary to pancreatic cancer compared with that of multidetector computed tomography (MDCT).

METHODS

From January 2002 to February 2003, we retrospectively studied 19 consecutive patients with pancreatic cancer. MDCT was performed on all patients prior to preoperative visceral angiography. Fourteen patients underwent CTAP + CTHA at the time of preoperative angiography.

RESULTS

Liver metastases were identified in 3 patients by means of MDCT. Of 14 patients who underwent CTAP + CTHA, 8 patients (57.1%) were diagnosed as having liver metastases, which could not be detected by MDCT. These tumors missed by MDCT ranged from 5 to 15 mm in size. On CTAP + CTHA, a single nodule in the liver was detected in 2 patients, 2 nodules in 2 patients, 3 lesions in 1 patient, and > or =4 lesions in 3 patients. The sensitivity and specificity of CTAP + CTHA versus MDCT were 75.0% versus 23.1% and 66.7% versus 100%, respectively.

CONCLUSIONS

In conclusion, the combination of CTAP and CTHA is useful to confirm liver metastases before operation for resectable pancreatic cancer because it has higher sensitivity to detect of liver metastases compared with MDCT.

Development of intraarterial contrast-enhanced 2D MRDSA with a 0.3 tesla open MRI system

PURPOSE

The purpose of this study was to develop a new technique for a high temporal resolution two-dimensional MR digital subtraction angiography (2D MRDSA) sequence under intraarterial injection of contrast material to permit the visualization of vascular anatomy and hemodynamics.

METHODS

2D MRDSA was imaged on a 0.3T open MR scanner with a T(1)-weighted fast gradient echo sequence. The phantom study examined vials containing gadolinium (Gd) solutions ranging in concentration from 0.5 mmol/L to 100 mmol/L. Repetition time and echo time were fixed at minimal values in order to achieve high temporal resolution, and only the flip angle was changed in 10-degree increments between 10 and 90 degrees. The in vivo study examined a brachial artery of a human volunteer. MRDSA images were acquired continuously during intraarterial injections of Gd solutions ranging in concentration from 0.5 mmol/L to 100 mmol/L. The subtracted images were displayed on the monitor in real time at a frame rate of one frame per second and evaluated to determine the optimal concentration of contrast material.

RESULTS

In the phantom study, a 10-mmol/L Gd concentration with a flip angle of 50 degrees -90 degrees and a 25-mmol/L Gd concentration with a flip angle of 60 degrees -90 degrees showed high signal-to-noise ratios. In the human brachial artery experiment, the forearm arteries were well visualized when solutions of 5-50 mmol/L Gd concentration were used. The 10- and 25-mmol/L Gd concentrations were considered optimal. The palmar digital arteries were also visualized. Higher Gd concentrations showed a paradoxical signal increase when diluted by blood.

CONCLUSION

We successfully developed an intraarterial contrast-enhanced 2D MRDSA sequence. With appropriate settings of imaging parameters and Gd concentrations, we obtained acceptable vessel visualization in the human study. The low Gd concentration for optimal visualization permits repeated intraarterial injections. This technique can be a useful tool for investigating the vascular anatomy and hemodynamics required for MR-guided vascular interventions.

Multislice CT angiography through an implantable catheter and port system: early experience in detection of vascular complications during hepatic arterial infusion chemotherapy

OBJECTIVE

The purpose of this study was to evaluate the use of multislice CT in the evaluation of vascular patency in patients during hepatic arterial infusion chemotherapy of liver tumors.

MATERIALS AND METHODS

Thirty-three patients were prospectively examined by CT angiography through the indwelling catheter and port system. Visibility of hepatic arteries and vascular patency were graded 0 to 3 and were compared with digital subtraction angiography (DSA).

RESULTS

Average visualization scores of CT angiography and DSA were 1.7 and 2.5, respectively, in common hepatic artery (CHA) and proper hepatic artery (PHA), 2.5 and 2.3 in right hepatic artery (RHA), 2.6 and 2.6 in left hepatic artery (LHA), 2.3 and 2.2 in segmental RHA, and 2.1 and 2.0 in segmental LHA. Stenoses were found in proximal hepatic arteries in 9 on CT angiography and 13 on DSA. Stenoses were found in branches of the hepatic artery in 21 on CT angiography and 16 on DSA.

CONCLUSION

The authors' results indicate that multislice CT angiography of the hepatic arteries is equivalent to DSA and may demonstrate vascular complications of hepatic arterial infusion chemotherapy.

Role of angiographic techniques in the preoperative staging and management of gastrointestinal neoplasms

Gastrointestinal neoplasms are very common diseases, and their management does not usually require angiography for diagnostic and staging purposes. However, angiography may be required for further refinements in staging of vascular involvement or to obtain a detailed preoperative anatomy of the vessels. Finally, angiographic techniques may be useful for palliative or preoperative locoregional chemotherapy, and to treat hemorrhagic complications. This article reviews the capabilities and limits of angiographic techniques in the assessment and management of tumors of the alimentary tract.