Detection Of Extrahepatic Disease Research Articles

A meta-analysis exploring the role of PET and PET-CT in the management of potentially resectable colorectal cancer liver metastasis.

3547Background: It has been proposed that PET alone or combined with CT imaging improves detection of extra-hepatic disease in colorectal cancer liver metastasis (CRCLM). The objective of this stud...

Systematic review and meta-analysis of the effect of pre-operative PET/PET-CT in the management of patients with potentially resectable colorectal cancer liver metastasis.

591 Background: It has been proposed that PET with 18F-fluorodeoxyglucose alone or combined with CT improves detection of extra hepatic disease in the setting of colorectal cancer liver metastasis (CRLM). However, there remains conflicting evidence on the added benefit of PET/PET-CT prior to liver resection, and its effect on long-term survival. Thus, we set out to perform a systematic review of literature and meta-analysis. Methods: From 2000 to April 2017, MEDLINE, EMBASE, and CENTRAL were searched for studies (prospective and retrospective) investigating the preoperative use of PET/PET-CT in the management of patients with CRLM. We excluded studies in which neoadjuvant chemotherapy was given 2 weeks prior to PET/PET-CT. Screening, data abstraction, and quality assessment was performed in duplicate. Primary outcome was overall survival (OS). Secondary outcomes included disease-free survival (DFS), pre-operative change in surgical management, and open-close surgery. Random effect models were used to pool treatment effects. The protocol was published in PROSPERO. Results: Of 4034 articles reviewed, 37 met the inclusion criteria and were analyzed, and 8 compared PET/PET-CT to conventional imaging. All studies included PET (n=18), PET-CT (n=17), or both (n=2). OS for all patients was similar whether or not pre-operative staging included PET/PET-CT (HR 0.94, 95% CI 0.69-1.26). A similar effect was seen in the subgroup of patients who underwent surgery (HR 0.92, 95% CI 0.72-1.17). DFS in patients who underwent surgery was not different either (HR 0.93, 95% CI 0.81-1.08). PET/PET-CT reduced the odds of undergoing an open-close surgery (OR 0.52, 95% CI 0.35-0.76) and changed the surgical management of 23.4% patients (95% CI 19.33-27.47), however heterogeneity (I2=100%). Conclusions: Pre-operative PET/PET-CT may have a meaningful impact on surgical decision making in CRLM, however heterogeneity between studies is high, likely due to different study designs. It may also reduce the rate of open-close surgeries. The addition of PET/PET-CT to routine pre-operative imaging does not improve OS or DFS.

Effect of chemotherapy on the impact of FDG-PET/CT in selection of patients for surgical resection of colorectal liver metastases: single center analysis of PET-CAM randomized trial.

To explore the relationship between prior chemotherapy and detection of metastatic disease on PET in patients from PET-CAM. Secondary aim: to determine whether centralized imaging interpretation could have impacted trial results. The study included 120 patients from a single institution. Local PET interpretation (PET-L) was recorded from the original database. Retrospective PET interpretation was performed independently by at least one additional reader (PET-C). The presence of extrahepatic disease (EHD) and significant additional liver metastases (=SALM), defined as metastases not originally planned for resection, was recorded. Patients were stratified to responders to recent chemotherapy (Group R) versus all others (Group O) according to surgical pathology and RECIST criteria. Thirty-seven of 50 patients who received recent chemotherapy (<90days) were responders (Group R). EHD was present in 30/120 (25%) patients. There was no difference in detection of EHD on PET-L (7/37;18.9%), PET-C (7/37;18.9%), and CT (4/37;10.8%) for Group R (p=0.375), but in Group O more EHD was detected on both PET-L (15/83;18.1%) and PET-C (22/83;26.5%) than CT (8/83;9.6%); p=0.039 and p<0.001, respectively. For the entire cohort, PET-L and PET-C detected EHD and/or SALM not reported on CT in 14 (11.7%) and 22 (18.3%) patients. The impact of recent chemotherapy on detection of colorectal metastases with PET suggests that the utility of PET in patient selection for liver resection in the prior PET-CAM-RCT may have been underestimated.

The influence of FDG PET-CT on the detection of extrahepatic disease in patients being considered for resection of colorectal liver metastasis.

The aim of this study was to evaluate the influence of flurodeoxyglucose positron emission tomography computed tomography (FDG PET-CT), as an adjunct to conventional CT staging, in the detection of extrahepatic disease in patients with potentially resectable colorectal liver metastasis. Overall, 133 consecutive patients with colorectal liver metastases staged with CT and PET-CT referred to the East Lancashire regional hepatobiliary multidisciplinary team over a two-year period were included in this study. Abnormal findings on PET-CT were correlated with follow-up imaging and/or histology. All imaging was reviewed by specialist hepatobiliary radiologists for the presence/absence of extrahepatic disease. The influence of the PET-CT findings was categorised for each patient in relation to operability and other significant findings. PET-CT had a major impact on staging of extra hepatic disease in 20% of patients, in comparison with the initial CT. Six per cent of patients were upstaged from operable CT findings to inoperable findings on PET-CT because of the discovery of inoperable occult extrahepatic disease. Five per cent had operable local regional nodal disease detected on PET-CT. A further 3% had premalignant colorectal lesions detected on PET-CT. Six per cent of patients were downstaged from indeterminate or suspected inoperable CT findings to operable findings on PET-CT. The use of PET-CT in this setting may prevent futile operations, guide the resection of local regional nodal disease and downstage a number of patients thought to have extrahepatic disease on conventional imaging. This study has shown similar results to other recent studies and supports the use of PET-CT as a necessary staging modality in patients with potentially resectable colorectal liver metastases.

A population-based study of the effect of FDG PET/CT in the management of liver-limited colorectal adenocarcinoma (CRC) metastases.

3610 Background: PET/CT scans are publically funded in British Columbia for staging in liver limited metastatic CRC. However, past studies have been equivocal about the utility of PET/CT as some report as high as a 20-30% change in management while others report &lt;10% change in management. Our primary objective was to assess the effect of the addition of PET/CT to CT scanning for the management of liver limited colorectal cancer. Methods: Patients who underwent PET/CT scan for de novo liver limited metastatic disease from 2005-2011 in the province of British Columbia were identified using the PET/CT database. Patients recently completed or currently on chemotherapy were excluded. We determined the concordance rates between CT and PET/CT scans with respect to the extra-hepatic disease, the number of lesions in the liver and the location of liver lesions. Results: 349 patients were identified. The most common indications for PET/CT scans after an initial CT scan were: detection of extrahepatic disease (77%), confirmation of the malignant nature of the liver lesions (8%) and the extent of extrahepatic disease (15%). PET/CT and CT were discordant in 39% of cases for the extent of metastatic disease. PET/CT revealed extrahepatic disease in 27% of the cases for which CT only detected liver limited disease. In contrast, 13% of patients were downstaged when CT liver lesions were demonstrated not to be FDG avid. Concordance of PET/CT and CT scans on the number and location of liver lesions was 52% and 85%, respectively. PET/CT revealed additional number of liver lesions and multilobar disease in 26% and 12% of cases, respectively. Furthermore, the median time between PET/CT and CT were 64.3 days and 64.1 days for concordant and discordant cases (p=0.88). Conclusions: PET/CT scans provided additional information compared to CT scans which could have implications for surgical management. Our study supports the utility and public funding of PET/CT in addition to CT in patients with potentially surgically curable metastatic CRC involving the liver.

In Colorectal Liver Metastases, the Presence of Extrahepatic Disease Correlates with the Pathology of the Primary Tumour

Background. FDG-PET scan detects extrahepatic metastases in 20% of patients with colorectal liver metastases but it is reported to have approximately 16% false negative rates. Patients and Methods. Patients who had PET scan for metastatic colorectal cancer at Westmead Hospital between March 2006 and March 2010 were reviewed retrospectively. The results of PET scan were correlated with tumour characteristics that were thought to affect the overall prognosis. Results. Degree of tumour differentiation and vascular invasion were significantly predictive for the presence of extrahepatic disease on PET scan, also did the level of CEA. Conclusion. The detection of extrahepatic disease in colorectal liver metastases correlates with the biologic behaviour of the primary tumour. Poorly differentiated tumours and those with lymphovascular invasion behave in aggressive fashion and likely to have wide-spread metastases. This should be considered when contemplating liver resection for colorectal metastases.

Moderne Bildgebung bei Lebermetastasen kolorektaler Tumoren

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.

Treatment of liver metastases, an update on the possibilities and results

Long-term results after liver resection for colorectal liver metastases show 5-year survival rates between 35 and 40%. However, only a limited number of patients appear to be candidates for resection, far more patients prove to have unresectable disease. Present challenges in liver surgery for colorectal metastases are to improve patient selection, to increase the resectability rate and to improve survival by multimodality treatment approaches. The variables most consistently associated with a poor prognosis and tumour recurrence are tumour-positive resection margins and the presence of extra-hepatic disease. Hence, patient selection and preoperative staging should concentrate on accurate imaging of the liver lesions and the detection of extrahepatic disease. For liver imaging, spiral computed tomography (CT) scan or magnetic resonance imaging (MRI), supplemented by intra-operative ultrasound, are currently regarded as the best methods for evaluating the anatomy and resectability of colorectal liver metastases. Extrahepatic disease should be investigated by spiral CT of the chest and abdomen and when possible by 2-fluouro-2-deoxy-d-glucose-positron emission tomography (FDG-PET). Resection remains the gold standard for the surgical treatment of colorectal liver metastases. In experienced centres, resection is a safe procedure and mortality rates are below 5%. The aim of resection should be to obtain tumour-negative resection margins. Edge cryosurgery should be considered in cases where very close resection margins are anticipated. The role of adjuvant chemotherapy after resection is still controversial, although two recent studies show a clear benefit. For the moment, local tumour ablative therapies such as cryotherapy and radiofrequency therapy should be considered as an adjunct to hepatic resection in those cases in which resection can not deal with all of the tumour lesions. In these cases, there seems a beneficial effect of a combined treatment consisting of resection and local tumour ablation. At this stage, there are no randomised data that local tumour ablation is as effective as resection. For a selected group of patients with unresectable liver metastases, there may be a chance to turn unresectable disease to resectable disease by aggressive neo-adjuvant chemotherapy or portal vein embolisation. For patients with unresectable disease, many different chemotherapy schedules may be used based on systemic drug administration. Regional chemotherapy and isolated liver perfusion should only be used within a study design.

Clinical experience with radiolabelled monoclonal antibodies in the detection of colorectal and ovarian carcinoma recurrence and review of the literature.

A retrospective study was carried out to determine the diagnostic value of OncoScint CR/OV immunoscintigraphy in assessing patients with suspected recurrence of carcinoma of the colon and ovary. The scintigraphic results of 31 patients were compared with surgical and histopathological findings, conventional radiological examinations and clinical disease outcome over an average 3-year follow-up. Detected lesions were divided by location into hepatic or extrahepatic and the latter group was classified as local recurrence at the resection site, pelvic or abdominal regional lymph node involvement and distant metastatic disease. The combined sensitivity and accuracy of immunoscintigraphy in the detection of extra-hepatic disease was significantly higher than that of cross-sectional radiological imaging (87% and 83% vs 44% and 53% respectively) with equal specificity of 74%. Scintigraphy identified 14 (36%) of 39 extra-hepatic malignant lesions not diagnosed by conventional radiological techniques and influenced therapeutic planning in 8 (26%) of 31 patients studied. In the liver, conventional imaging had a significantly higher detection rate than immunoscintigraphy (sensitivity 93% vs 28%). In conclusion, these results show that OncoScint scintigraphy is a sensitive method for the detection of local recurrence and extra-hepatic metastases in colorectal and ovarian carcinoma and has an important role in the therapeutic decision-making process.

Hepatic metastases: CT versus MR imaging at 1.5T

A prospective multi-institutional study was performed to compare the sensitivity of computed tomography (CT) and high-field magnetic resonance (MR) imaging (1.5T) in the detection of hepatic metastases. T1-weighted and 72-weighted spin-echo (SE) MR images were compared with noncontrast, dynamic, and delayed CT. Sixty-nine oncology patients were studied. Noncontrast CT showed an overall sensitivity of 57%, dynamic CT 71%, delayed CT 72%, T1-weighted SE MR 47%, and T2-weighted SE MR 78%. Although there was no statistically significant (p less than 0.05) difference among dynamic CT, delayed CT, and T2-weighted SE MR, these three methods were significantly more sensitive (p less than 0.005) than noncontrast CT or T1-weighted SE MR. T2-weighted SE MR was significantly more sensitive (p less than 0.006) than CT or T1-weighted SE MR in the detection of small (less than 1 cm) lesions. CT was more sensitive in the detection of extrahepatic disease. These data confirm the superiority of T2-weighted SE over T1-weighted SE pulse sequences at 1.5T.