Dynamic Hepatic Scintigraphy Research Articles

Prospective assessment of the hepatic perfusion index in patients with colorectal cancer

This prospective study was designed to test the hypothesis that abnormal liver blood flow is related to poor prognosis in patients with colorectal cancer. The hepatic perfusion index (HPI), measured by dynamic hepatic scintigraphy, was assessed in 202 patients with colorectal cancer. Assessment for overt hepatic metastasis included liver palpation at laparotomy and perioperative computed tomography (CT). Follow-up at a dedicated clinic included regular abdominal ultrasonography and CT. The HPI was abnormal (greater than 0.37) in 92 (88 per cent) of 105 patients with overt liver metastases. Of 89 patients with no evidence of overt metastases or residual tumour after primary resection, 52 had an abnormal and 37 a normal HPI. At a median follow-up of 39 (range 13-76) months, 25 of 38 patients with recurrence had an abnormal HPI. Some 31 of 45 patients who died had an abnormal HPI. The HPI predicted overall recurrence (P=0.04, log rank test). Multivariate analysis showed the HPI was independent of Dukes stage for predicting disease-free survival (P=0.04, relative risk 1.94 (95 per cent confidence interval (c.i.) 1.03-3.67)) but this just failed to attain significance for overall survival (P=0.055, relative hazard 1.88 (95 per cent c.i. 1.00-3.58)). The HPI predicts a poor outcome in patients with colorectal cancer and may be useful in patient selection for adjuvant chemotherapy.

Abnormal hepatic perfusion index predicts recurrence of colorectal carcinoma

The hepatic perfusion index (HPI) is a ratio of the gradient of hepatic arterial to total hepatic blood flow. This study correlated HPI with histopathological indicators of prognosis and disease-free survival following curative resection of colorectal cancer. HPI was measured preoperatively by dynamic hepatic scintigraphy in 37 patients with a primary colorectal cancer and no evidence of distant metastases who underwent a curative resection. Abnormally elevated HPI were detected in 49% of patients and were significantly more frequent in association with locally advanced tumours (T3 and T4) in comparison with early tumours (T1 and T2; 59% vs 20%, respectively; P=0.04). There was no association between abnormal HPI and presence of lymph node metastases or degree of tumour differentiation. The 18-month disease-free survival rate of patients with abnormal HPI was significantly shorter than that of patients with normal HPI (53% vs 100%, respectively; P=0.01), and this was independent of the T category. HPI predicts the risk of recurrent colorectal carcinoma, and this measurement should be included in the panel of prognostic markers in future clinical trials.

Risk-benefit assessment of methotrexate in the treatment of severe psoriasis.

Methotrexate is an established and highly effective systemic treatment for severe psoriasis, including the pustular and erythrodermic forms. It has been widely used during the last 3 decades. For this reason, the long term adverse effects of methotrexate are well known, in contrast to other relatively new systemic treatments like cyclosporin and retinoids. The most frequent adverse effects occurring during methotrexate therapy are abnormal liver function tests, nausea and gastric complaints. The most feared adverse effects are myelosuppression and hepatotoxicity. Because hepatotoxicity is related to a high cumulative dose of methotrexate, rotational therapy or an intermittent instead of a continuous treatment schedule are advised. The histological assessment of liver biopsies, according to the international guidelines, remains the gold standard for detection of liver damage until equally reliable noninvasive screening methods for liver damage--tentatively dynamic hepatic scintigraphy (DHS) or measurement of levels of serum aminoterminal propeptide of type III procollagen--are well evaluated. Low dose methotrexate therapy is relatively well tolerated, provided that there is careful patient selection and regular monitoring for adverse effects and drug interactions during methotrexate therapy is carried out. The long term clinical efficacy and relative safety of methotrexate remain impressive.

The value of dynamic hepatic scintigraphy and serum aminoterminal propeptide of type III procollagen for early detection of methotrexate-induced hepatic damage in psoriasis patients

Oral methotrexate (MTX) is a highly effective drug for the treatment of severe psoriasis. A limitation of this treatment is its potential hepatotoxicity. In the present prospective study the value of dynamic hepatic scintigraphy (DHS) and serum aminoterminal propeptide of type III procollagen (PIIINP) were investigated as screening methods for early detection of MTX-induced hepatic damage. These relatively non-invasive procedures were compared with the liver biopsy classification, until now the gold standard to assess MTX-induced liver damage. Twenty-five MTX patients were studied. The mean cumulative MTX dose was 3.9 g (range 0.2-11.1 g). Twenty-one patients had a normal liver histology (grade I), three patients had steatosis (grade II), and one patient mild fibrosis (grade IIIA). Seven additional patients with non-MTX related hepatic cirrhosis were included as disease controls. DHS showed a clear-cut separation between the portal contribution of the MTX patients with grade I liver histology, and that of all other patients. A portal contribution larger than 52% was associated with a > 95% chance of normal liver histology. If this cut-off value had been used to postpone the liver biopsy, this would have resulted in at least a 55% reduction in the number of biopsies in patients with a normal liver histology. DHS appeared to be very promising as a screening test to differentiate between the presence or absence of MTX-induced hepatic damage, but appeared not suitable to grade the severity of hepatic damage. Although a global relationship was demonstrated between serum PIIINP concentration and hepatic damage, single measurements in individual patients were not reliable. The combination of PIIINP measurements with DHS had only a limited additional value above DHS alone. The present study indicates that DHS has great promise for the detection of early MTX-induced hepatic damage. Pending further studies, regular liver biopsies remain mandatory for the safe prolonged use of MTX in psoriasis patients.

The value of dynamic hepatic scintigraphy and serum aminoterminal propeptide of type III procollagen for early detection of methotrexate-induced hepatic damage in psoriasis patients

The value of dynamic hepatic scintigraphy and serum aminoterminal propeptide of type III procollagen for early detection of methotrexate-induced hepatic damage in psoriasis patients

Hepatic perfusion index

The hepatic perfusion index (HPI) in patients with hepatocellular carcinoma (HCC) and the correlation between HPI and survival was assessed. From September 1989 to March 1990, 36 patients with HCC and 32 normal volunteers underwent dynamic hepatic scintigraphy to estimate the HPI. Serum alpha-fetoprotein (AFP) and tumour size were also evaluated in all patients. A HPI > or = 0.85, AFP > or = 3000 ng ml-1 and tumour size > or = 8 cm chosen were as the cutoff points to obtain the highest differences in predicting survival. The HPI in HCC patients was significantly higher than in the normal controls (P < 0.0001). Survival was significantly different according to different HPI, AFP and tumour size with P < 0.0001, P = 0.007 and P = 0.01, respectively. It is concluded that the HPI is significantly elevated in patients with HCC. In addition, it is a useful prognostic factor and superior to AFP and tumour size in predicting the survival of patients with HCC.

Dynamic hepatic scintigraphy in the screening of psoriatic patients for methotrexate-induced hepatotoxicity.

We report the use of dynamic hepatic scintigraphy in the assessment of the hepatic status of psoriatic patients before and during methotrexate therapy. Eighty-seven paired dynamic scans and percutaneous liver biopsies were performed in 63 patients. The liver biopsies were graded according to Warin et al. with fibrosis of grade 2 or worse being a strong indication for withdrawal of methotrexate. The sensitivity of dynamic hepatic scintigraphy in detecting fibrosis of grade 2 or worse was 83.3% and the specificity was 81.5%. The predictive value of a normal scan for fibrosis of grade 0-1 was high (98.5%) although the predictive value of an abnormal scan for fibrosis of grade 2 or worse was low (25%). Dynamic hepatic scintigraphy may therefore offer a means to reduce the number of liver biopsies necessary in patients receiving methotrexate for psoriasis.

Clinical correlation of high activity dynamic hepatic scintigraphy in patients with colorectal cancer.

The hepatic perfusion index, the ratio of hepatic arterial to total liver blood flow, was measured in 50 consecutive patients with colorectal cancer using radiolabelled colloid with high administered activity. In patients with proven liver metastases the diagnostic sensitivity of the HPI was 96% and the predictive value of a negative test was 92%. Dynamic hepatic scintigraphy is of value in the management of patients with colorectal cancer.

Dynamic hepatic scintigraphy

The hepatic perfusion index (HPI) may be of value in the detection of both overt and occult hepatic metastases in patients with colorectal carcinoma. Using the standard technique, the low counts obtained in each region of interest can produce statistical unreliability in the curve generation and render many studies unsuitable for analysis. In this study the effects of a high administered activity (400 MBq) on the inter- and intra-observer reproducibility of dynamic hepatic scintigraphy was investigated in 18 consecutive patients with colorectal cancer. All 18 patient studies were suitable for analysis by two observers. The correlation coefficient of measurements between observers was 0.98 (P less than 0.000 01 linear regression analysis), with a root mean square difference of replicate HPI measurements between observers of 0.045. The median range of HPI for four reprocessings by one observer was 0.035, with a maximum range of 0.11. Although high administered activity improves count statistics, for the individual patient study the activity used is not the major source of uncertainty in the derived HPI value.

Dynamic liver scanning in cirrhosis.

Dynamic hepatic scintigraphy was performed in 49 patients with established cirrhosis, using intravenous 99Tcm-pertechnetate and 99Tcm-sulphur colloid in a prospective study of its predictive value. There was a close correlation between the hepatic perfusion index (reflecting the ratio of arterial to total hepatic blood flow) obtained with pertechnetate (HPI-P) and with sulphur colloid (HPI-C) (r = 0.775; p less than 0.0001), and both indices correlated with disease severity (HPI-P p less than 0.0001; HPI-C p less than 0.01). HPI-P was significantly increased in patients who died, in patients with varices and in those with hepatic encephalopathy. HPI-C was significantly increased in patients with varices, in patients with hepatic encephalopathy and in those who had bled from varices. Neither HPI-P nor HPI-C was able accurately to predict the development of complications during the follow-up period. The trapping index (TI), reflecting a combination of hepatic extraction efficiency, degree of intrahepatic shunting and extrahepatic extraction of colloid, was significantly impaired in patients who died and in those with ascites, varices and/or variceal bleeding, but not in patients with hepatic encephalopathy. The trapping index correlated with disease severity, as did the computer-derived spleen-liver ratio (S-L ratio). Neither TI nor S-L ratio was able to predict the development of complications. The clearance rate constant of colloid from peripheral blood, the uptake rate constants for liver and spleen, and splenic volume were all found to be unhelpful as indicators of disease severity or as predictors of complications. While perfusion indices derived by dynamic hepatic scintigraphy reflect the severity of the underlying liver disease, their determination on a single occasion appears to offer no benefit in predicting the likelihood of major complications.

Hepatic perfusion index in cirrhotic livers—investigation of imaging and analytical procedures

Dynamic hepatic scintigraphy was performed in a group of cirrhotic patients to evaluate the optimum imaging and analytical procedures necessary for the measurement of the hepatic perfusion index (HPI). Patients were studied in the posterior (n = 19) and the anterior (n = 14), positions, with either 0.2 or 0.5 ml of 99Tcm sulphur colloid administered as a rapid bolus injection. In each subject, three ROIs (small, medium and large) were drawn over the liver, and time-activity perfusion curves were generated. Analytical techniques were developed to allow flexibility in selecting the arterial and portal venous phases of the liver perfusion curve. The quality of the bolus, expressed as the full width at half-maximum of the left ventricular time--activity curve, was independent of the bolus volumes and patient positioning. The dispersion in the data and the inter-observer variation were less in the anterior view using medium and large ROIs, compared with the anterior small ROI and all the posterior ROI sizes. A time delay between liver and kidney arterial phases, if ignored, produced statistically significant effects on the values of the HPI. We conclude that HPI investigations are best performed in the anterior projection. Data analysis using a large liver ROI is preferred, and flexible data-processing techniques are recommended, particularly in the presence of a liver and kidney arterial time delay.

Noninvasive assessment of portosystemic shunting in extrahepatic portal hypertension in rats

A simple reproducible animal model of extrahepatic portal hypertension (EHPHT) has been developed in weanling Wistar rats using a two-stage ligation of the portal vein. This model consistently produces substantial collaterals, both portosystemic (hepatofugal) and portoportal (hepatopetal). Using dynamic hepatic scintigraphy (DHS) with 99mTechnetium sulphurcolloid, hepatopetal collateral flow was measured as the mesenteric fraction (MF) of total hepatic blood flow and compared with measurement of hepatofugal collateral flow (portosystemic shunting) following intraportal injection of radiolabeled microspheres. Strong and significant correlation between the two assessments was found with reduction in MF denoting increased portosystemic shunting (PSS). The technique of DHS has been used successfully in adults to assess compromised portal venous flow and is a simple noninvasive test to aid diagnosis, assessment, and follow-up of children with EHPHT.

Liver tumour blood flow and responses to arterial embolization measured by dynamic hepatic scintigraphy.

Liver and tumour blood flow has been studied in 30 patients with multiple liver metastases and in 14 patients with solitary liver tumours by means of dynamic hepatic scintigraphy. Observations were compared with those of a group of 33 control subjects. Haemodynamic changes were also measured in 10 patients who underwent hepatic arterial embolization (HAE). The mesenteric fraction (MF) to tumour regions in 32 subjects showed a wide range compared with control subjects. In 9 patients the MF to the tumour region was within the normal range suggesting that some tumours may possess a portal venous supply. The MF to the uninvolved liver regions was below the normal range in 25% of patients, indicating that HAE could be hazardous in this group. Following HAE the MF rose in all 4 tumour regions and fell in 4 non-embolized uninvolved liver regions. No increase in colloid clearance rate (k) was seen though a significant decrease occurred in 4 patients. These changes may well represent increased portal venous flow into tumours.

Studies of hepatic tolerance of polyvinylpyrrolidone in the rat

Intraperitoneal polyvinylpyrrolidone in amounts much larger than used in povidone-iodine for peritonitis or for adhesion prophylaxis was administered to rats. No adverse effects on hepatic reticulo-endothelial function could be detected using dynamic hepatic scintigraphy and fewer histochemical changes occurred than expected.