Helical CT versus CT arterial portography in the detection of hepatic metastasis of colorectal carcinoma

Colon cancer: the 2023 Korean clinical practice guidelines for diagnosis and treatment

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients' values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Contemporary Validation of a Nomogram Predicting Colon Cancer Recurrence, Revealing All-Stage Improved Outcomes

Background

The Memorial Sloan Kettering Cancer Center (MSK) colon cancer recurrence nomogram is a risk calculator that provides patients and clinicians with individualized prediction of recurrence following curative resection of colon cancer. Although validated on multiple separate cohorts, the nomogram requires periodic updating as patient care changes over time. The aim of this study was to evaluate the nomogram’s accuracy in a contemporary cohort and modify the tool to reflect improvements in outcome related to advances in colon cancer therapy.

Methods

A contemporary patient cohort was compiled, including consecutive colon cancer patients undergoing curative resection for stage I–III colon adenocarcinoma at MSK from 2007 to 2014. The nomogram’s predictive accuracy was assessed by concordance index and calibration plots of predicted vs actual freedom from recurrence at 5 years after surgery.

Results

Data from a total of 999 eligible patients with complete records were used for validation. Median follow-up among survivors was 37 months. The concordance index was 0.756 (95% confidence interval = 0.707 to 0.805), indicating continued discriminating power, but the calibration plot revealed that the nomogram overestimated recurrence risk. Recalibration of the nomogram by estimating a new baseline freedom-from-recurrence function restored the nomogram’s accuracy.

Conclusion

The updated nomogram retains the original nomogram’s variables but includes a lower baseline estimation of recurrence risk, reflecting improvements in outcomes for all stages of colon cancer, likely resulting from advances in imaging and integration of multiple treatment modalities.

Positron Emission Tomography–Computed Tomography (PET-CT) Versus No PET-CT in the Management of Potentially Resectable Colorectal Cancer Liver Metastases: Cost Implications of a Randomized Controlled Trial

Purpose:

To evaluate whether positron emission tomography (PET) combined with computed tomography (PET-CT) is cost saving, or cost neutral, compared with conventional imaging in management of patients with resectable colorectal cancer liver metastases.

Methods:

Cost evaluation of a randomized trial that compared the effect of PET-CT on surgical management of patients with resectable colorectal cancer liver metastases. Health care use data ≤ 1 year after random assignment was obtained from administrative databases. Cost analysis was undertaken from the perspective of a third-party payer (ie, Ministry of Health). Mean costs with 95% credible intervals (CrI) were estimated by using a Bayesian approach.

Results:

The estimated mean cost per patient in the 263 patients who underwent PET-CT was $45,454 CAD (range, $1,340 to $181,420) and in the 134 control patients, $40,859 CAD (range, $279 to $293,558), with a net difference of $4,327 CAD (95% CrI, −$2,207 to $10,614). The primary cost driver was hospitalization for liver surgery (difference of $2,997 CAD for PET-CT; 95% CrI, −$2,144 to $8,010), which was mainly a result of a longer length of hospital stay for the PET-CT arm (median, 7 v 6 days; P = .03) and a higher postoperative complication rate (20% v 10%; P = .01). Baseline characteristics were similar between groups, including the number of liver segments involved with cancer, number of segments resected, and type of liver resection performed. No difference in survival was detected between arms.

Conclusion:

PET-CT was associated with limited clinical benefit and a nonsignificant increased cost. Universal funding of PET-CT in the management of patients with resectable colorectal cancer liver metastases does not seem justified.

A simulation model of colorectal cancer surveillance and recurrence

Background

Approximately one-third of those treated curatively for colorectal cancer (CRC) will experience recurrence. No evidence-based consensus exists on how best to follow patients after initial treatment to detect asymptomatic recurrence. Here, a new approach for simulating surveillance and recurrence among CRC survivors is outlined, and development and calibration of a simple model applying this approach is described. The model’s ability to predict outcomes for a group of patients under a specified surveillance strategy is validated.

Methods

We developed an individual-based simulation model consisting of two interacting submodels: a continuous-time disease-progression submodel overlain by a discrete-time Markov submodel of surveillance and re-treatment. In the former, some patients develops recurrent disease which probabilistically progresses from detectability to unresectability, and which may produce early symptoms leading to detection independent of surveillance testing. In the latter submodel, patients undergo user-specified surveillance testing regimens. Parameters describing disease progression were preliminarily estimated through calibration to match five-year disease-free survival, overall survival at years 1–5, and proportion of recurring patients undergoing curative salvage surgery from one arm of a published randomized trial. The calibrated model was validated by examining its ability to predict these same outcomes for patients in a different arm of the same trial undergoing less aggressive surveillance.

Results

Calibrated parameter values were consistent with generally observed recurrence patterns. Sensitivity analysis suggested probability of curative salvage surgery was most influenced by sensitivity of carcinoembryonic antigen assay and of clinical interview/examination (i.e. scheduled provider visits). In validation, the model accurately predicted overall survival (59% predicted, 58% observed) and five-year disease-free survival (55% predicted, 53% observed), but was less accurate in predicting curative salvage surgery (10% predicted; 6% observed).

Conclusions

Initial validation suggests the feasibility of this approach to modeling alternative surveillance regimens among CRC survivors. Further calibration to individual-level patient data could yield a model useful for predicting outcomes of specific surveillance strategies for risk-based subgroups or for individuals. This approach could be applied toward developing novel, tailored strategies for further clinical study. It has the potential to produce insights which will promote more effective surveillance—leading to higher cure rates for recurrent CRC.

Indeterminate pulmonary nodules in rectal cancer: a recommendation for follow-up guidelines

BACKGROUND

Incidental visualization of indeterminate pulmonary nodules is considered a clinical dilemma.

METHODS

We identified patients for inclusion in this study by searching for the term "indeterminate nodules" in the radiology database of rectal cancer patients who underwent surgery. Patients with definite metastatic disease were excluded.

RESULTS

In total, 224 patients underwent chest computerized tomography (CT) and 59 of these patients had indeterminate pulmonary nodules detected more than twice by CT scan. Six patients (10.2%) were confirmed to have metastatic lesions on follow-up evaluation. Pulmonary nodule size (P=0.028), pathologic N status (P=0.049), positive nodal status (P=0.036) and the number of positive lymph nodes (P=0.033) were significant risk factors for pulmonary metastasis. In the pulmonary metastasis group, the patients who had received adjuvant oxaliplatin-based (FOLFOX4) chemotherapy had longer intervals to developing metastasis compared to patients who had not received it.

CONCLUSIONS

It is not necessary to perform excessive surveillance routinely for all rectal cancer patients who have indeterminate pulmonary lesions. Intensive follow-up chest CT or other invasive diagnostic modalities should be considered only in patients with pulmonary nodules larger than 5.7 mm or positive nodal status. In addition, patients receiving adjuvant FOLFOX4 chemotherapy should be followed-up for longer periods.

Ten-year survival after liver resection for colorectal metastases: systematic review and meta-analysis

Background. Liver resection in metastatic colorectal cancer is proved to result in five-year survival of 25–40%. Several factors have been investigated to look for prognostic factors stratifications such as resection margins, node involvement in the primary disease, and interval between the primary disease and liver metastases. Methods. We searched MEDLINE and EMBASE for studies that reported ten-year survival. Metaanalysis was performed to analyse the effect of recognised prognostic factors on cure rate for colorectal metastases. The meta-analysis was performed according to Ottawa-Newcastle method of analysis for nonrandomised trials and according to the guidelines of the PRISMA. Results. Eleven studies were included in the analysis, which showed a ten-year survival rate of 12–36%. Factors that have favourable impact are clear resection margin, low level of CEA, single metastatic deposit, and node negative disease. The only factor that excluded patients from cure is the positive status of the resection margin. Conclusion. Predicted ten-year survival after liver resection for colorectal metastases varies from 12 to 36%. Only positive resection margins resulted in no 10-year survivors. No patient can be excluded from consideration for liver resection so long the result is negative margins.

Outcome of small liver nodules detected by computed tomographic angiography in patients with hepatocellular carcinoma

PURPOSE

Hepatic lesions identified by computed tomography (CT) during arterial portography (CTAP) or CT hepatic arteriography (CTHA) in hepatocellular carcinoma (HCC) patients are sometimes too small to be diagnosed as HCC. We undertook this cohort study to assess whether these small lesions are actually HCC, and to clarify the effectiveness of these imaging examinations in a clinical setting.

METHODS

We assessed the characteristics of 74 tiny lesions detected by CTAP and/or CTHA, but not by CT in 67 patients.

RESULTS

Seven out of 10 nodules were histologically confirmed as HCC and 18 out of 64 lesions increased in size and showed typical findings of HCC during the follow-up period. Multivariate analysis revealed that the size of the main tumor (>30 mm in diameter) was associated with the presence of tiny additional HCC lesions (P = 0.002).

CONCLUSIONS

These findings indicate that CTAP and CTHA are recommended for determining the stage of HCC, especially when the HCC nodule is larger than 30 mm in diameter.

Magnetic resonance imaging of the liver: New imaging strategies for evaluating focal liver lesions

The early detection of focal liver lesions, particularly those which are malignant, is of utmost importance. The resection of liver metastases of some malignancies (including colorectal cancer) has been shown to improve the survival of patients. Exact knowledge of the number, size, and regional distribution of liver metastases is essential to determine their resectability. Almost all focal liver lesions larger than 10 mm are demonstrated with current imaging techniques but the detection of smaller focal liver lesions is still relatively poor. One of the advantages of magnetic resonance imaging (MRI) of the liver is better soft tissue contrast (compared to other radiologic modalities), which allows better detection and characterization of the focal liver lesions in question. Developments in MRI hardware and software and the availability of novel MRI contrast agents have further improved the diagnostic yield of MRI in lesion detection and characterization. Although the primary modalities for liver imaging are ultrasound and computed tomography, recent studies have suggested that MRI is the most sensitive method for detecting small liver metastatic lesions, and MRI is now considered the pre-operative standard method for diagnosis. Two recent developments in MRI sequences for the upper abdomen comprise unenhanced diffusion-weighted imaging (DWI), and keyhole-based dynamic contrast-enhanced (DCE) MRI (4D THRIVE). DWI allows improved detection (b = 10 s/mm²) of small (< 10 mm) focal liver lesions in particular, and is useful as a road map sequence. Also, using higher b-values, the calculation of the apparent diffusion coefficient value, true diffusion coefficient, D, and the perfusion fraction, f, has been used for the characterization of focal liver lesions. DCE 4D THRIVE enables MRI of the liver with high temporal and spatial resolution and full liver coverage. 4D THRIVE improves evaluation of focal liver lesions, providing multiple arterial and venous phases, and allows the calculation of perfusion parameters using pharmacokinetic models. 4D THRIVE has potential benefits in terms of detection, characterization and staging of focal liver lesions and in monitoring therapy.

Preoperative investigations for metastatic staging of colon and rectal cancer across multiple centres--what is current practice?

OBJECTIVE

The optimal strategy for elective distant staging of colorectal carcinoma (CRC) has yet to be defined, with current guidelines based on small and limited series. One specific issue requiring review is the value of routine computerized tomographic (CT) chest examination. Also lacking is data on current routine clinical practice.

METHOD

A retrospective chart review of consecutive cases of elective surgery for CRC from five hospitals.

RESULTS

Two hundred and fifty-seven cases were reviewed, 128 colon and 129 rectal primaries. 164 (64%) of patients overall, ranging from 45% to 88% across the individual centres, had a preoperative serum CEA level performed. CT abdomen/pelvis was performed in 222 (86%) of cases, ranging from 69% to 98% per centre. CT chest was performed in 95 (37%) of cases, 47% of rectal vs 29% of colon cancers (P = 0.004). In 17 cases (18%) CT chest examinations revealed abnormalities suspicious for metastatic disease, leading to a change in management in six (35%) of these cases. Of the 17 cases with an abnormal CT chest, in only 5 of the 14 (36%) where carcinoembryonic antigen (CEA) levels were also recorded was this increased, and in only three (21%) was this markedly (> 10 microg/l) elevated.

CONCLUSIONS

Substantial variability exists in the preoperative evaluation of patients with CRC. Many patients do not have a CEA and/or abdominal imaging performed. Where performed, CT chest revealed suspicious findings in a significant number of patients, the vast majority of whom had a normal or near normal CEA. Future studies are required to define optimal preoperative staging.

Detection of colo-rectal liver metastases: prospective comparison of contrast enhanced US, multidetector CT, PET/CT, and 1.5 Tesla MR with extracellular and reticulo-endothelial cell specific contrast agents

BACKGROUND

To compare contrast-enhanced US (CE-US), multidetector-CT (MDCT), 1.5 Tesla MR with extra-cellular (Gd-enhanced) and intracellular (SPIO-enhanced) contrast agents and PET/CT, in the detection of hepatic metastases from colorectal cancer.

MATERIALS AND METHODS

A total of 34 patients with colo-rectal adenocarcinoma underwent preoperatively CE-US, MDCT, Gd- and SPIO-enhanced MR imaging (MRI), and PET/CT. Each set of images was reviewed independently by two blinded observers. The ROC method was used to analyze the results, which were correlated with surgical findings, intraoperative US, histopathology, and MDCT follow-up.

RESULTS

A total of 57 hepatic lesions were identified: 11 hemangiomas, 29 cysts, 1 focal fatty liver, 16 metastases (dimensional distribution: 5/16 < 5 mm; 3/16 between 5 mm and <10 mm; 8/16 ≥ 10 mm). Six of 34 patients were classified as positive for the presence of at least one metastasis. Considering all the metastases and those ≥ 10 mm, ROC areas showed no significant differences between Gd- and SPIO-enhanced MRI, which performed significantly better than the other modalities (P < 0.05). Considering the lesions <10 mm, ROC areas showed no significant differences between all modalities; however MRI presented a trend to perform better than the other techniques. Considering the patients, ROC areas showed no significant differences between all the modalities; however PET/CT seemed to perform better than the others.

CONCLUSIONS

Gd- and SPIO-enhanced MRI seem to be the most accurate modality in the identification of liver metastases from colo-rectal carcinoma. PET/CT shows a trend to perform better than the other modalities in the identification of patients with liver metastases.

Should indeterminate lung lesions reported on staging CT scans influence the management of patients with colorectal cancer?

OBJECTIVE

The aim of this study was to determine the significance of indeterminate lung lesions reported from staging CT scans on patients with colorectal cancer.

METHOD

CT-scan reports of 439 patients were reviewed to identify patients in which indeterminate lung lesion had been reported. The tumour, node, metastasis (TNM) stage of these patients was recorded together with any follow-up scan reports or multidisciplinary team (MDT) discussions regarding these lesions.

RESULTS

Twenty-three patients had definite lung metastases. Forty-five patients had indeterminate lung lesions. Of these, 22 patients had N1 or N2 disease, 20 had N0 disease and three patients were not operated on due to comorbidity. Of these 45 patients, 30 had further follow-up scans. In 19, the indeterminate lesions were unchanged and were therefore downgraded to benign lesions. The lesions had progressed or new lesions had developed in five. These patients were therefore shown to have metastatic lung disease. All five of these patients had N1 or N2 disease. One patient had a primary rather than metastatic lung lesion. Follow-up scans showed the lesion to be no longer present in five. Of the remainder, One patient declined further follow up. Three patients did not have a follow up scan for reasons not mentioned in their records. Two patients were not scanned because further MDT review of the original scans showed that the lesions were not metastases. Four patients died before follow up scans were done. (one postoperative myocardial infarction (MI), one postoperative sepsis, one postoperative cerebrovascular accident (CVA) and one inferior vena cava (IVC) obstruction). Five patients have not yet had follow-up scan at the time of writing.

CONCLUSION

Since the introduction of spiral CT scanners, smaller lesions are being seen at the time of preoperative staging. Our study concludes that only a small proportion of indeterminate lung lesions did develop into definite metastases and those that did had node positive disease. Indeterminate lung lesions are not a reason to delay surgery for colorectal cancer.

Real time contrast enhanced ultrasonography in detection of liver metastases from gastrointestinal cancer

Background

Contrast enhanced ultrasound (CEUS) is an imaging technique which appeared on the market around the year 2000 and proposed for the detection of liver metastases in gastrointestinal cancer patients, a setting in which accurate staging plays a significant role in the choice of treatment.

Methods

A total of 109 patients with colorectal (n = 92) or gastric cancer prospectively underwent computed tomography (CT) scan and conventional US evaluation followed by real time CEUS. A diagnosis of metastases was made by CT or, for lesions not visibile at CT, the diagnosis was achieved by histopathology or by a malignant behavior during follow-up.

Results

Of 109 patients, 65 were found to have metastases at presentation. CEUS improved sensitivity in metastatic livers from 76.9% of patients (US) to 95.4% (p <0.01), while CT scan reached 90.8% (p = n.s. vs CEUS, p < 0.01 vs US). CEUS and CT were more sensitive than US also for detection of single lesions (87 with US, 122 with CEUS, 113 with CT). In 15 patients (13.8%), CEUS revealed more metastases than CT, while CT revealed more metastases than CEUS in 9 patients (8.2%) (p = n.s.).

Conclusion

CEUS is more sensitive than conventional US in the detection of liver metastases and could be usefully employed in the staging of patients with gastrointestinal cancer. Findings at CEUS and CT appear to be complementary in achieving maximum sensitivity.

Prospective, blinded comparison of helical CT and CT arterial portography in the assessment of hepatic metastasis from colorectal carcinoma

OBJECTIVE

This prospective blinded comparison of helical CT and helical CT arterial portography aimed to detect liver metastasis from colorectal carcinoma.

METHODS AND MATERIALS

50 patients with colorectal carcinoma were evaluated comparing helical CT with helical CT arterial portography. Each imaging study was evaluated on a 5-point ROC scale by radiologists blinded to the other imaging findings, and the results were compared, with the surgical and pathologic findings as the gold standard.

RESULTS

Of the 127 lesions found at pathology identified as metastatic colorectal cancer, helical CT correctly identified 85 (69%) and CT portography 96 (76%). When subgroups with lesions <3 cm (48 patients) and patients with maximum tumor size <3 cm (18 patients) were considered, CT portography was always better than helical CT in terms of sensitivity, specificity, positive predictive value, and negative predictive value. ROC analysis adjusting for multiple lesions per patient revealed significantly greater area under the curve (AUC) for the subgroup of lesions <3 cm (CT-AUC of 77% and CT portography AUC of 81%; P = 0.002).

CONCLUSIONS

For identification of large metastases, helical CT and CT portography have similar yield. However, for detection of small liver metastases, CT portography remains superior for lesion detectability.

The diagnostic value of multiplanar reconstruction on MDCT colonography for the preoperative staging of colorectal cancer

The purpose of this study was to determine whether multiplanar reconstruction (MPR) images can improve the accuracy of MDCT-based colorectal cancer preoperative staging by receiver-operating characteristic (ROC) analysis. Fifty-five patients with colorectal cancer underwent contrast-enhanced CT colonography using an 8- or 16-row scanner. Two separate interval reviews of the axial MDCT datasets with/without MPR images (coronal and sagittal) were performed independently by two radiologists blinded to both the colonoscopic and histopathologic results. At each review session, the radiologists were asked to determine the colorectal cancer TNM stage within the context of differentiating < or =T3 from T4, N0 from > or =N1 and M0 from M1 using a five-point confidence scale. The radiologists' performance for staging the colorectal cancer using axial CT datasets with/without MPR images was evaluated using ROC analysis. Sensitivities, specificities and interobserver agreement were assessed. When MPR images were added, significant improvement was achieved by both radiologists for differentiating N0 from > or =N1 in terms of both A(Z) (0.651 to 0.769; 0.573 to 0.713) and specificity (26.7 to 69.2%; 23.1 to 76.9%) (P<0.05). For T staging, ROC analysis failed to show a significant improvement in terms of differentiating < or =T3 from T4 for either radiologist (P>0.05), but a significant improvement in the specificity (70 to 90%; 80 to 92%) was achieved by one radiologist (P<0.05). In terms of the M staging, a significant improvement in the Az (0.844 to 0.996) was observed for the combined interpretation of the axial and MPR images by one radiologist (P<0.05). Furthermore, substantial or almost perfect interobserver agreement was achieved for all TNM stagings for the combined interpretations (kappa=0.641-0.866), whereas only fair to substantial agreement was achieved for the axial images alone (kappa=0.337-0.707). In conclusion, the combined interpretation of the axial and MPR MDCT images significantly improved the local staging of colorectal cancer compared with assessments based on axial images alone.

New MR techniques for the detection of liver metastases

It is well established that hepatic resection improves the long-term prognosis of many patients with liver metastases. However, incomplete resection does not prolong survival, so knowledge of the exact extent of intra-hepatic disease is crucially important in determining patient management and outcome. MR imaging is well recognised as one of the most sensitive methods for detecting metastases. Recent developments in gradient coil design, the use of body phased array coils and the availability of novel MR contrast agents have resulted in MR being recognised as the pre-operative standard in this group of patients. However, diagnostic efficacy is extremely dependent on the choice and optimisation of pulse sequences and the appropriate use of MR contrast agents. This article reviews current MR imaging techniques for the detection and characterisation of metastases and discusses the relative capability of different techniques for detecting small lesions.

Survival after hepatic resection for colorectal metastases: a 10-year experience

BACKGROUND

Metastatic colorectal cancer is a major cause of cancer death in North America. Hepatic resection offers the potential for cure in selected patients. We report the long-term outcomes of patients who underwent hepatic resection for colorectal metastases over a 10-year period at a single hepatobiliary surgical oncology center.

METHODS

All patients who underwent liver resection for metastatic colorectal cancer between 1992 and 2002 were identified. Data were retrospectively obtained through chart review. Major outcome variables were disease-free survival and overall survival. Risk factors for disease recurrence and mortality were identified by multivariate analysis by using the Cox proportional hazard method.

RESULTS

A total of 423 hepatectomies were performed for metastatic colorectal cancer. Most operations (n = 276; 65%) were major (four or more segments) hepatectomies. Perioperative morbidity occurred in 74 (17%) patients. There were seven (1.6%) perioperative deaths. The disease-free survival at 1, 5, and 10 years was 64%, 27%, and 22%, respectively. The overall survival at 1, 5, and 10 years was 93%, 47%, and 28%, respectively. Multivariate analysis identified four negative predictive factors for overall survival (hazard ratio; 95% confidence interval): a positive surgical margin (2.9; 1.5-5.3), large metastases (>5 cm; 1.5; 1.1-2.0), multiple metastases (1.4; 1.1-1.9), and age >60 years (1.4; 1.1-1.9).

CONCLUSIONS

Hepatic resection for metastatic colorectal cancer is safe and provides good long-term overall survival rates of 47% at 5 years and 28% at 10 years. An aggressive approach is justified by the low operative mortality rate and good long-term survival, even in individuals with multiple bilobar metastases.

[Modern imaging for liver metastases from colorectal tumors]

Cross-sectional imaging modalities such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and Positron emission tomography (PET)/CT have benefited from rapid technical advances in recent years. In patients with colorectal tumors, multislice CT is the standard technique for preoperative evaluation and follow-up. It is faster than single-slice helical CT and allows for excellent 3D imaging of liver anatomy and tumor volumetry. The most accurate technique for detecting and characterizing focal liver lesions is MRI using state-of-the-art scanners and liver-specific contrast agents and should be used for preoperative evaluation of all possible surgical candidates. Whole-body FDG-PET and PET/CT are most useful in the detection of extrahepatic disease and may alter clinical management in up to 20% of patients by detecting extrahepatic spread of disease.

Liver metastases in candidates for hepatic resection: comparison of helical CT and gadolinium- and SPIO-enhanced MR imaging

PURPOSE

To prospectively compare accuracy of dynamic contrast material-enhanced thin-section multi-detector row helical computed tomography (CT), high-spatial-resolution three-dimensional (3D) dynamic gadolinium-enhanced magnetic resonance (MR) imaging, and superparamagnetic iron oxide (SPIO)-enhanced MR imaging with optimized gradient-echo (GRE) sequence for depiction of hepatic lesions; surgery and histologic analysis were the reference standard.

MATERIALS AND METHODS

Local ethics committee approval was granted, and written informed consent was obtained. Fifty-eight patients (45 men, 13 women; age range, 47-82 years) with hepatic metastases were imaged with multi-detector row CT (3.2-mm section thickness), 3D dynamic gadolinium-enhanced MR imaging (2.5-mm effective section thickness), and SPIO-enhanced MR by using an optimized T2-weighted GRE sequence. Images were reviewed independently by two blinded observers who identified and localized lesions with a four-point confidence scale. Accuracy of each technique was measured with alternative free-response receiver operating characteristic analysis. Results were correlated with findings at surgery with intraoperative ultrasonography or histopathologic examination. Statistical differences among techniques for each observer were measured.

RESULTS

Accuracy values for each observer for all metastases (n = 215) and 1.0-cm or smaller metastases (n = 80), respectively, follow: For CT, those for reader 1 were 0.82 and 0.65; for reader 2, 0.81 and 0.68. For gadolinium-enhanced MR imaging, those for reader 1 were 0.92 and 0.79; for reader 2, 0.90 and 0.76. For SPIO-enhanced MR imaging, those for reader 1 were 0.92 and 0.83; for reader 2, 0.92 and 0.81. For all metastases for both observers, there was no significant difference between MR techniques, but both were significantly more accurate than CT (P < .01). For metastases 1.0 cm or smaller and one observer, there was no significant difference between MR techniques, but both were more accurate than CT (P < .01); for the other observer, SPIO-enhanced MR imaging was more accurate than gadolinium-enhanced MR imaging (P < .05) and CT (P < .02), but there was no significant difference between gadolinium-enhanced MR imaging and CT (P = .2).

CONCLUSION

Accuracy for gadolinium-enhanced MR imaging and SPIO-enhanced MR imaging was similar. Both techniques were significantly more accurate than CT.

Colorectal liver metastases: CT, MR imaging, and PET for diagnosis--meta-analysis

PURPOSE

To perform a meta-analysis to obtain sensitivity estimates of computed tomography (CT), magnetic resonance (MR) imaging, and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for detection of colorectal liver metastases on per-patient and per-lesion bases.

MATERIALS AND METHODS

MEDLINE, EMBASE, Web of Science, and CANCERLIT databases and Cochrane Database of Systematic Reviews were searched for relevant original articles published from January 1990 to December 2003. Criteria for inclusion of articles were as follows: Articles were reported in the English, German, or French language; CT, MR imaging, or FDG PET was performed to identify and characterize colorectal liver metastases; histopathologic analysis (surgery, biopsy, or autopsy), intraoperative observation (manual palpatation, intraoperative ultrasonography [US]), and/or follow-up US was the reference standard; and data were sufficient for calculation of true-positive or false-negative values. A random-effects linear regression model was used to obtain sensitivity estimates in assessment of liver metastases.

RESULTS

Of 165 identified relevant articles, 61 fulfilled all inclusion criteria. Sensitivity estimates on a per-patient basis for nonhelical CT, helical CT, 1.5-T MR imaging, and FDG PET were 60.2%, 64.7%, 75.8%, and 94.6%, respectively; FDG PET was the most accurate modality. On a per-lesion basis, sensitivity estimates for nonhelical CT, helical CT, 1.0-T MR imaging, 1.5-T MR imaging, and FDG PET were 52.3%, 63.8%, 66.1%, 64.4%, and 75.9%, respectively; nonhelical CT had lowest sensitivity. Estimates of gadolinium-enhanced MR imaging and superparamagnetic iron oxide (SPIO)-enhanced MR imaging were significantly better, compared with nonenhanced MR imaging (P = .019 and P < .001, respectively) and with helical CT with 45 g of iodine or less (P = .02 and P < .001, respectively). For lesions of 1 cm or larger, SPIO-enhanced MR imaging was the most accurate modality (P < .001).

CONCLUSION

FDG PET had significantly higher sensitivity on a per-patient basis, compared with that of the other modalities, but not on a per-lesion basis. Sensitivity estimates for MR imaging with contrast agent were significantly superior to those for helical CT with 45 g of iodine or less.

Perfusion imaging of the liver: current challenges and future goals

Improved therapeutic options for hepatocellular carcinoma and metastatic disease place greater demands on diagnostic and surveillance tests for liver disease. Existing diagnostic imaging techniques provide limited evaluation of tissue characteristics beyond morphology; perfusion imaging of the liver has potential to improve this shortcoming. The ability to resolve hepatic arterial and portal venous components of blood flow on a global and regional basis constitutes the primary goal of liver perfusion imaging. Earlier detection of primary and metastatic hepatic malignancies and cirrhosis may be possible on the basis of relative increases in hepatic arterial blood flow associated with these diseases. To date, liver flow scintigraphy and flow quantification at Doppler ultrasonography have focused on characterization of global abnormalities. Computed tomography (CT) and magnetic resonance (MR) imaging can provide regional and global parameters, a critical goal for tumor surveillance. Several challenges remain: reduced radiation doses associated with CT perfusion imaging, improved spatial and temporal resolution at MR imaging, accurate quantification of tissue contrast material at MR imaging, and validation of parameters obtained from fitting enhancement curves to biokinetic models, applicable to all perfusion methods. Continued progress in this new field of liver imaging may have profound implications for large patient groups at risk for liver disease.

Metastatic Colorectal Carcinoma: Cost-effectiveness of Percutaneous Radiofrequency Ablation versus That of Hepatic Resection

PURPOSE

To evaluate the relative cost-effectiveness of radiofrequency (RF) ablation and hepatic resection in patients with metachronous liver metastases from colorectal carcinoma (CRC) and compare the outcomes, cost, and cost-effectiveness of a variety of treatment and follow-up strategies.

MATERIALS AND METHODS

A state-transition decision model for evaluating the (societal) cost-effectiveness of RF ablation and hepatic resection in patients with CRC liver metastases was developed. The model tracks the presence, number, size, location, growth, detection, and removal of up to 15 individual metastases in each patient. Survival, quality of life, and cost are predicted on the basis of disease extent. Imaging, ablation, and resection affect outcomes through detection and elimination of individual metastases. Several patient care strategies were developed and compared on the basis of cost, effectiveness, and incremental cost-effectiveness (expressed as dollars per quality-adjusted life-year [QALY]). Extensive sensitivity analysis was performed to evaluate the impact of alternative scenarios and assumptions on results.

RESULTS

A strategy permitting ablation of up to five metastases with computed tomographic (CT) follow-up every 4 months resulted in a gain of 0.65 QALYs relative to a no-treat strategy, at an incremental cost of $2400 per QALY. Compared with this ablation strategy, a strategy permitting resection of up to four metastases, one repeat resection, and CT follow-up every 6 months resulted in an additional gain of 0.76 QALYs at an incremental cost of $24 300 per QALY. Across a range of model assumptions, more aggressive treatment strategies (ie, ablation or resection of more metastases, treatment of recurrent metastases, more frequent follow-up imaging) were superior to less aggressive strategies and had incremental cost-effectiveness ratios of less than $35 000 per QALY. Findings were insensitive to changes in most model parameters; however, results were somewhat sensitive to changes in size thresholds for RF ablation, the number of metastases present, and surgery and treatment costs.

CONCLUSION

RF ablation is a cost-effective treatment option for patients with CRC liver metastases. However, in most scenarios, hepatic resection is more effective (in terms of QALYs gained) than RF ablation and has an incremental cost-effectiveness ratio of less than $35 000 per QALY.

Recent advances in CT imaging of liver metastases

Multidetector computed tomography provides robust evaluation of the hepatic parenchyma. It plays a critical role in the detection of liver metastases and the assessment of treatment response to therapy. In this article, we discuss the role of multidetector computed tomography in the detection and characterization of hepatic metastases, and the value of image processing with volume rendering and maximum-intensity projection techniques in the accurate delineation of hepatic vascular anatomy and the segmental localization of lesions. This information is critical in the diagnosis and treatment of patients with metastatic disease and is essential in surgical and nonsurgical planning.

Supervivencia y recidiva en el tratamiento multidisciplinario del carcinoma colorrectal

BACKGROUND AND OBJECTIVE

Colorectal cancer is one of the most frequent causes of death in the general population. Our aim was to analyze our experience in the multidisciplinary approach of colorectal carcinoma during a three year period.

PATIENTS AND METHOD

Between January 1996 and December 1998, we studied prospectively 807 patients with colorectal cancer. The epidemiology, treatment and outcome(recurrence and survival) were analyzed. The minimum follow-up was 3 years.

RESULTS

There were 598 colon (65.5%) and 279 rectal (34.5%) tumors in all the series. Surgical treatment was elective in 84% and urgent in 16%, and was considered radical in 598 cases (74.1%). Chemotherapy or radiotherapy was administered in 49.6% and 18.3% patients, respectively. The overall 3-year survival was as follows: stage I 97.5%, stage II 90.6%, stage III 75.2%, and stage IV 12.6%. The 3-year free-disease survival was as follows: in colon cancer 97.8% for stage I, 87.3% for stage II, and 71.4% for stage III; and in rectal cancer 96.8% for stage I, 85.1% for stage II, and 75.4% for stage III. During the follow-up 124 patients (20.7%) developed recurrence: local (2.8%), systemic (15.9%) or both (2%). The three-year survival in operated patients with liver metastases was 61.9%.

CONCLUSIONS

We have observed adequate survival and recurrence rates which are the result are of systematic protocols established by a multidisciplinary team.

Detection of hypovascular hepatic metastases at triple-phase helical CT: sensitivity of phases and comparison with surgical and histopathologic findings

PURPOSE

To compare the respective sensitivities of unenhanced, arterial-dominant, and portal-dominant phase helical computed tomography (CT) in the preoperative depiction of hypovascular hepatic metastases by using intraoperative ultrasonographic (US) and histopathologic findings as the standard of reference.

MATERIALS AND METHODS

In this prospective study, 32 patients with 59 surgically and histopathologically proved hypovascular hepatic metastases underwent triple-phase helical CT of the liver, which included unenhanced, arterial-dominant, and portal-dominant phase scanning. Images from each phase were separately analyzed by three readers, and disagreements were resolved with consensus readings. The findings on CT images were compared with intraoperative US and histopathologic findings on a lesion-by-lesion basis to determine the sensitivity of each imaging phase. Statistical review of the lesion-by-lesion analysis was performed by using the Wilcoxon rank sum test.

RESULTS

Among 59 hepatic metastases, unenhanced, arterial-dominant, and portal-dominant phase helical CT imaging depicted 39 (66.1%; 95% CI: 53.3%, 76.8%), 44 (74.5%; 95% CI: 62.2%, 83.9%), and 54 (91.5%; 95% CI: 81.6%, 96.3%) metastases, respectively. Portal-dominant phase imaging depicted significantly more hypovascular hepatic metastases than did unenhanced (P <.001) or arterial-dominant (P <.01) phase imaging (Wilcoxon test).

CONCLUSION

Preoperative use of triple-phase helical CT in patients with hypovascular hepatic metastases may not be warranted. Portal-dominant phase helical CT imaging allows depiction of significantly more hypovascular hepatic metastases than does imaging during any of the other phases.

Surgically staged focal liver lesions: accuracy and reproducibility of dual-phase helical CT for detection and characterization

PURPOSE

To assess the accuracy and reproducibility of dual-phase helical computed tomography (CT) in enabling preoperative detection and characterization of surgically staged focal liver lesions.

MATERIALS AND METHODS

Surgically and histopathologically proven liver lesions were evaluated by three experienced CT readers. These lesions were present in 77 patients who underwent dual-phase helical CT. Images were interpreted separately by the three blinded reviewers. Each lesion was graded on a nine-point scale of confidence, with 1 being definitely benign, 9 being definitely malignant, and 5 being indeterminate. The chi2 test was used to determine if the distribution of lesion classifications was different between readers.

RESULTS

There was a total of 237 lesions: 73 were benign and 164 were malignant. Sensitivity for lesion detection was 69%, 70%, and 71% for the three reviewers, respectively. Specificity was 91%, 86%, and 90%, and the area under the curve for the alternative-free response receiver operating characteristic curve was 0.84, 0.83, and 0.85, respectively. The difference in the distributions of lesion classification between the three reviewers was not statistically significant (P =.67) as determined by chi2 analysis.

CONCLUSION

Dual-phase CT has sensitivity of 69%-71% and high specificity (86%-91%) in enabling the detection and characterization of focal liver lesions. Interpretation is highly reproducible, as there is minimal variation between experienced reviewers.

Cost-effectiveness of hepatic metastasectomy in patients with metastatic colorectal carcinoma: a state-transition Monte Carlo decision analysis

OBJECTIVE

To evaluate the cost-effectiveness of hepatic resection ("metastasectomy") in patients with metachronous liver metastases from colorectal carcinoma (CRC), and to investigate the impact of operative and follow-up strategies on outcomes, cost, and cost-effectiveness.

SUMMARY BACKGROUND DATA

There is substantial evidence that resection of CRC liver metastases can result in long-term survival in some patients. However, several unresolved issues are difficult to address using currently available clinical data. These include the appropriate threshold for resection, whether to perform repeat resection, and the relative cost-effectiveness of the procedure(s).

METHODS

The authors developed a state-transition Monte Carlo decision model to evaluate the (societal) cost-effectiveness of hepatic metastasectomy in patients with metachronous CRC liver metastases. The model tracks the presence, number, size, location, growth, detection, and removal of up to 15 individual metastases in each patient. Survival, quality of life, and cost are predicted on the basis of disease extent. Imaging and surgery affect outcomes via detection and removal of individual metastases. Several patient management strategies were developed and compared with respect to cost, effectiveness, and incremental cost-effectiveness ($/quality-adjusted life year [QALY]). A reference strategy in which metastasectomy is not offered and imaging is not performed for the purpose of assessing resectability or operative planning ("no-surgery" strategy) was included for comparison. Extensive sensitivity analysis was performed to evaluate the impact of alternative model assumptions on results.

RESULTS

A strategy permitting resection of up to six metastases and one repeat resection, with CT follow-up every 6 months, resulted in a gain of 2.63 QALYs relative to the no-test/no-treat strategy, at an incremental cost of 18,100 US dollars/QALY. When additional surgical strategies were considered, the incremental cost-effectiveness ratio (ICER; relative to the next least effective strategy) of the six metastases, one repeat, 6-month strategy was 31,700 US dollars/QALY. Across a range of model assumptions, more aggressive treatment strategies (i.e., resection of more metastases, resection of recurrent metastases) were superior to less aggressive strategies and had ICERs below 35,000 US dollars/QALY. Findings were insensitive to changes in most model parameters but somewhat sensitive to changes in surgery and treatment costs.

CONCLUSIONS

Hepatic metastasectomy is a cost-effective option for selected patients with metachronous CRC metastases limited to the liver. When considering metastasectomy, more aggressive approaches are generally preferred to less aggressive approaches. Overall, surgeons should be encouraged to consider resection for all patients whose metastases can technically be removed.

Scientific surgery

The British Journal of Surgery is committed to practice of surgery based on scientific evidence. Each month we will publish a list of randomized trials and meta-analyses collated from English language publications. A collection of all these papers will be available in the Scientific Surgery Archive which will be held on The British Journal of Surgery website together with links to free Medline sites where the full papers can be accessed (see below for details). If you have published a recent randomized trial which has not been featured in Scientific Surgery, the Editors would be pleased to receive a reprint and consider its inclusion.

Multi-detector row helical CT in preoperative assessment of small (< or = 1.5 cm) liver metastases: is thinner collimation better?

PURPOSE

To determine the value of collimations less than 5 mm in detecting hepatic metastases 1.5 cm or smaller by using multi-detector row helical computed tomography (CT).

MATERIALS AND METHODS

Thirty-one patients underwent contrast material-enhanced multi-detector row helical CT before hepatic resection in this prospective study. Images were reconstructed at collimations of 5.00, 3.75, and 2.50 mm with 50% overlap and reviewed independently by three radiologists. Each lesion was characterized as metastatic, benign, or equivocal and graded for conspicuity. Criterion standards were pathologic assessment of the resected liver and follow-up of the nonresected liver. Only lesions 1.5 cm or smaller were analyzed.

RESULTS

There were a total of 88 liver lesions 1.5 cm or smaller, and 25 of these were metastases. Pooled sensitivity for all lesions improved with thinner collimation (66% [58 of 88 lesions], 69% [61 of 88], and 82% [72 of 88] at collimations of 5.00, 3.75, and 2.50 mm, respectively), and this was statistically significant (P =.01). However, no significant difference was noted between collimations in the pooled sensitivity for metastatic lesions (80% [20 of 25 lesions] at all collimations) (P >.99). No statistical difference was noted in the conspicuity of lesions at different collimations (P =.18).

CONCLUSION

Image reconstruction with multi-detector row helical CT at collimations less than 5 mm may not improve sensitivity in the detection of hepatic metastases 1.5 cm or smaller.

Detection of hepatic metastases from cancers of the gastrointestinal tract by using noninvasive imaging methods (US, CT, MR imaging, PET): a meta-analysis

PURPOSE

To perform a meta-analysis to compare current noninvasive imaging methods (ultrasonography [US], computed tomography [CT], magnetic resonance [MR] imaging, and (18)F fluorodeoxyglucose [FDG] positron emission tomography [PET]) in the detection of hepatic metastases from colorectal, gastric, and esophageal cancers.

MATERIALS AND METHODS

A MEDLINE literature search and review of article bibliographies and our institutional charts of patients with colorectal cancer identified data with histopathologic correlation or at least 6 months of patient follow-up. Two authors independently abstracted data sets and excluded data without contingency tables or data published more than once. Summary-weighted estimates of sensitivity were obtained and stratified according to specificity of less than 85% or 85% and higher. A covariate analysis was used to evaluate the influence of patient- or study-related factors on sensitivity.

RESULTS

Among 111 data sets, nine US (509 patients), 25 CT (1,747 patients), 11 MR imaging (401 patients), and nine PET (423 patients) data sets met the inclusion criteria. In studies with a specificity higher than 85%, the mean weighted sensitivity was 55% (95% CI: 41, 68) for US, 72% (95% CI: 63, 80) for CT, 76% (95% CI: 57, 91) for MR imaging, and 90% (95% CI: 80, 97) for FDG PET. Results of pairwise comparison between imaging modalities demonstrated a greater sensitivity of FDG PET than US (P =.001), CT (P =.017), and MR imaging (P =.055).

CONCLUSION

At equivalent specificity, FDG PET is the most sensitive noninvasive imaging modality for the diagnosis of hepatic metastases from colorectal, gastric, and esophageal cancers.

Hepatic metastases in patients with colorectal cancer: relationship between size of metastases, standard of reference, and detection rates

PURPOSE

To determine the relationship between the size of hepatic metastases, the standard of reference, and the reported detection rate in patients with colorectal cancer.

MATERIALS AND METHODS

With use of a MEDLINE search (January 1994 to January 2001), articles were selected that contained original results on detection of hepatic metastases of colorectal cancer, categorized for size in at least two categories, with use of helical computed tomography (CT), helical CT at arterial portography, or magnetic resonance imaging. Results were compared with the size distribution of hepatic metastases in 47 consecutive patients with colorectal carcinoma, which were detected by using a combination of intraoperative ultrasonography (US) and palpation.

RESULTS

Seven studies met all predefined criteria. Four studies involved intraoperative US in all patients and demonstrated a significant negative correlation (-0.988) between detection rate and fraction of small metastases. These studies had a higher fraction and lower detection rate of small metastases and a lower overall detection rate. A majority (58% [145 of 252]) of metastases in the study population were smaller than 20 mm.

CONCLUSION

Few articles adequately describe the standard of reference and size distribution of hepatic lesions. Hepatic metastases of colorectal cancer are frequently smaller than 20 mm. When the standard of reference is suboptimal, many small metastases are excluded from analysis, and detection rates are therefore inflated.

Liver lesions: manganese-enhanced MR and dual-phase helical CT for preoperative detection and characterization comparison with receiver operating characteristic analysis

PURPOSE

The purpose of this study was to compare, by means of receiver operating characteristic (ROC) analysis, dual-phase helical computed tomography (CT) and manganese-enhanced magnetic resonance (MR) imaging in the detection and characterization of hepatic lesions in patients prior to surgery.

MATERIALS AND METHODS

Twenty-five patients known to have or suspected of having hepatic lesions who were eligible for surgery underwent dual-phase (ie, arterial and portal phase) helical CT and phased-array MR imaging (ie, unenhanced fast spin-echo T2-weighted imaging and gradient-echo T1-weighted imaging performed before and after administration of mangafodipir trisodium). All images were reviewed independently by three off-site blinded reviewers who separately reviewed the CT scans and MR images. The standard of reference was findings at surgery, intraoperative ultrasonography (US), and histopathologic examination. ROC curves were established to analyze the results for each reader and modality.

RESULTS

Ninety-four lesions (77 malignant and 17 benign) were revealed at surgery, intraoperative US, and/or histopathologic examination. The overall rate of lesion detection for the three readers at CT was 81.9% +/- 7.8, 90.4% +/- 5.9, and 76.6% +/- 8.6. At MR imaging, the detection rates were 72.3% +/- 9.0, 71.3% +/- 9.1, and 69.1% +/- 9.3 (P =.001 for the difference between MR and CT). The average rate of false-positive diagnoses in patients was 14.1% at CT and 6.4% at MR imaging (P =.06 for the difference between MR and CT). The mean areas under the alternative-free-response ROC curves were 0.74 for MR and 0.72 for CT (P =.751, not significant).

CONCLUSION

In detection and characterization of liver lesions, manganese-enhanced MR imaging and dual-phase helical CT were not statistically different.

Improved detection and biopsy of solid liver lesions using pulse-inversion ultrasound scanning and contrast agent infusion

The purpose of this study was to assess the ability of pulse-inversion ultrasound (US) scanning (PIUS), combined with an IV contrast agent, to detect malignant liver lesions and its impact on patient management (resectability). Additionally, to determine the feasibility of US-guided biopsy of new PIUS-findings at the same session. A total of 30 patients with known or clinically suspected cancer underwent conventional B-mode scanning and PIUS with IV-administered contrast agent. The number of liver metastases in the right and the left liver lobe, respectively, was recorded. All patients with additional findings by PIUS underwent US-guided biopsy. PIUS provided additional information in 18 patients (60%); of these, 13 (43%) had additional metastases. Of 19 patients found resectable by conventional US, 9 (47%) were considered inoperable using PIUS supported by biopsies. Biopsies of additional findings were performed in 17 of 18 patients. All biopsies of additional findings confirmed malignancy. PIUS with an IV contrast agent increased the ability to detect liver metastases compared to conventional US scanning. The technique had a high impact on patient management. The results showed that PIUS-guided biopsy was possible. PIUS with IV contrast will undoubtedly become an important diagnostic tool in the evaluation of patients with metastatic liver disease.

Computed tomography and magnetic resonance imaging of hepatic metastases

The detection and characterization of liver metastases is well performed with either computed tomography or magnetic resonance imaging. The administration of intravenous contrast is essential for almost all indications, with multiphasic imaging aiding in lesion characterization and detection. The use of multidetected CT (MDCT) provides the ability for optimized vascular and multiplanar imaging, but has also resulted in increased examination complexity. Tissue-specific MR contrast agents can yield the highest rate of lesion detection and thus may be useful in presurgical planning.

[Clinical study of 437 consecutive hepatectomies]

BACKGROUND

The aim of this prospective study was to analyze the risk of liver resection in unselected patients.

PATIENTS AND METHOD

From 1990 to 2000, 437 consecutive hepatectomies were performed in our center. Most frequent indications were liver metastases (n = 288), hepatocellular carcinoma (n = 62), Klatskin tumor (n = 17), gallblader carcinoma (n = 139) and other malignant tumors (n = 6). The indication was a benign tumor in 51 patients. In 357 cases the liver parenchyma was normal, 51 patients had an underlying cirrhosis and 17 patients had an obstructive jaundice.

RESULTS

Overall mortality was 3.6% (15 cases). Mortality in benign tumors was lacking. The prevalence of postoperative complications was 43.9%, which was mainly influenced by malignancy (46.9% vs 21.6%, p = 0.001) and type of tumor (Klastkin tumor, p # 0.001). Major liver resection (p < 0.001), blood transfusion (p < 0.001), age over 60 years (p = 0.001) and the type of hepatectomy (p < 0.001) also increased significantly the morbidity. The prevalence of biliary fistula was 11.2%, which was mainly related to the type of hepatectomy (major hepatectomy; p = 0.002) and a biliary-enteric anastomosis (p < 0.001). The prevalence of hepatic insufficiency was 3.6%, and chief risk factors for its development were underlying liver disease and major liver resection (p = 0.017).

CONCLUSIONS

Mortality after hepatectomy in experienced centers is low. Morbidity is mainly related to the amount of parenchyma resected, type of hepatectomy, underlying liver disease and associated procedures. Liver resection should be performed preferentially in centers with high volume by specialized surgeons.

Hepatic metastases from colorectal cancer: preoperative detection and assessment of resectability with helical CT

PURPOSE

To prospectively evaluate helical computed tomography (CT) in the preoperative detection of hepatic metastases and assessment of resectability with surgical, intraoperative ultrasonographic (US), and histopathologic correlation.

MATERIALS AND METHODS

Between October 1995 and December 1998, preoperative staging with helical CT (5-mm collimation; reconstruction interval, 5 mm) was performed in 157 patients with hepatic metastases. Iodinated contrast material was injected intravenously (160-170 mL; rate, 2.5-3.0 mL/sec); acquisition began at 60-70 seconds. Four radiologists prospectively assessed the metastatic involvement of the liver by indicating the number and location of the lesions; resection was indicated in 113 patients (119 instances). Helical CT findings were correlated with pathologic and surgical findings on a lesion-by-lesion basis.

RESULTS

Intraoperative US, palpation, and histopathologic examination revealed 290 liver metastases; helical CT correctly depicted 247. Helical CT results were the following: overall detection rate, 85.1% (95% CI: 80.8%, 89.3%); positive predictive value, 96.1% (95% CI: 92.9%, 98.1%); and false-positive rate, 3.9% (10 of 257 findings; 95% CI: 1.9%, 7.1%). False-positive findings were related to hemangioendothelioma, hemangioma, hepatic peliosis, biliary adenoma, centrilobar hemorrhage, biliary hamartoma, periportal fibrosis, and normal liver parenchyma. Curative resection was performed in 112 instances with a resectability rate of 94.1%. Four-year patient survival rate was 58.6%.

CONCLUSION

Helical CT is a noninvasive, reliable, and accurate technique for imaging the liver and should be considered as the standard preoperative work-up of hepatic metastases from colorectal cancer.