LIVER SCANNING I N COLORECTAL CARCINOMA
WONG AND ONG
LIVER SCANNING IN PATIENTS WITH COLORECTAL CARCINOMA J O H N WONG AND G. B. ONG Department of Surgery, University of Hong Kong, Queen Mary Hospital, Hong Kong
Three hundred l i v e r scans were performed o n a routine basis in patients with colorectal carcinoma, before and after operation, t o detect hepatic metastases. In 98 o f 106 preoperative and 28 of 194 postoperative scans, confirmation of the pathological condition was obtained a t operation o r post-mortem examination. T h e overall diagnostic accuracy of the scan was 77.4%, b u t the false-positive rate was high. T h e presence of focal defects in l i v e r scans before operation did n o t influence our decision regarding abdominal exploration. A f t e r operation 'on patients who did n o t have disseminated disease and whose liver scans showed localized focal defects, selective hepatic arteriography and abdominal exploration did not reveal resectable metastatic disease. In one-third of patients w i t h abnormal l i v e r scans after operation, subsequent scans returned t o normal. O f the patients w i t h t r u e positive liver scans, three-quarters had clinically evident hepatic metastases. Serum alkaline phosphatase estimations were as accurate in detecting liver metastases as the liver scan, and returned fewer false-positive results. Routine l i v e r scanning before o r after operation i s n'ot recommended f o r patients w i t h colorectal carcinoma and should be reserved f o r patients w i t h clinical features o r biochemical abnormalities suggestive o f l i v e r metastases.
THE value of radioisotope scanning in the diagnosis of focal or diffuse diseases in the liver appears established. There is disagreement, however, in the diagnostic accuracy and therefore in the clinical usefulness of this investigation in detecting hepatic metastases (Smith and Williams, I@S; Ariel et alii, 1969; Poulose et alii, 1969; Castagna et alii, 1972; du Priest et alii, 1973; Ranson et alii, 1973; Rosenthal and Kaufman, 1973). This discrepancy in results may be partly due to the inclusion, in most reported series, of diverse types of primary carcinomas as well as sarcomas and lymphomas, which renders the interpretation of results less exact. Routine liver scanning before and after operation has been advocated by Poulose eb a& (1969) and Andrews et alii (1973) in order to detect unsuspected hepatic metastases and so help in planning appropriate therapy. The purpose of this study has been to assess the accuracy of the liver scan when only patients with carcinoma of one part of the Reprints : Dr John Wong, address as above.
76
gastrointestinal tract, the large bowel, are included, and to determine the value of routine liver scanning in the management of the patient before and after operation. This paper reports the results of 300 liver scans performed in 201 patients with colorectal cancers. The accuracy of serum alkaline phosphatase estimations and clinical assessment in detecting hepatic metastases has also been compared with that of the liver scans.
PATIENTS AND METHODS Between 1971 and 1975, patients admitted to the University Surgical Unit, Queen Mary Hospital, Hong Kong, with a diagnosis of colorectal carcinoma, were included in the study for preoperative liver scanning. Two groups of patients were excluded: those presenting with acute complications requiring immediate operation, and those who had to wait more than four weeks for the scan examination. The liver scan was performed by a Phillips rectilinear scanner using 113 m indium colloid. Usually only the anterior view was recorded unless the scan was abnormal, when a lateral view was aIso obtained. AUST. N.Z. J. SURG.,
VOL.
47-NO.
I,
FEBRUARY, 1977
LIVER SCANNING I N COLORECTAL CARCINOMA
The liver scan was classified as normal or abnormal according to the .official interpretations made at the time the examination was performed. I t was considered normal if it was read as normal or if it showed diffuse nonuniform uptake without focal lesions. It was considered abnormal if focal defects were reported, irrespective of the nature of radioisotope uptake in the rest of the liver. At operation the liver was examined for evidence of metastatic or other disease. Small peritoneal seedlings on the liver surface in the absence of intrahepatic deposits were not included as hepatic metastases. After operation patients were scanned at half-yearly to yearly intervals. Patients who did not have preoperative liver scans were also included. These patients comprise those who presented with acute complications, those who would otherwise have had a long delay before operation, and those referred to our Unit after surgery. If the scan was abnormal, the examination was repeated. If this abnormality TABLE I Preoperative Liver Scans : Correlation with operative and Clinical Findings Operative findings
Scan results
Confirmed
Normal 76 Abnormal 30
71 27
Clinically evident Other liver Normal Metastases pathology metastases
61 I2
9
' 4
I* I**
I I0
* Cirrhosis. ** Recurrent pyogenic cholangitis.
persisted and unilobar hepatic metastasis was suspected, hepatic arteriography was performed. If scan and arteriographic findings both suggested localized disease, exploration with a view to hepatic resection was recommended to the patient. Only scans performed within one month of operation or post-mortem examination were regarded as confirmed. The clinical criteria for the diagnosis of hepatic metastases included hepatomegaly of at least 7 cm and associated with induration, tenderness or nodules (Fenster and Klatskin, 1961). The serum alkaline phosphatase level (SAP) was estimated in all patients before operation, A figure of 15 King-Armstrong units/roo ml or more was regarded as elevated (the normal figure is less than 13 units/Ioo ml in our laboratory). AUST. N.Z. J. SURG.,VOL.47-No.
I,
FEBRUARY, 1977
WONG AND ONG
RESULTS Preoperative liver scans were performed in 106 patients with large-bowel cancers. Table I shows the correlation of scan results with operative and clinical findings. In nine patients out of 71 with normal scans, metastases were found-a false-negative rate of 12.6%. On the other hand, 12 out of 27 patients with abnormal liver scans had normal livers - a false-positive rate of 44.4%. Clinically evident liver metastasis was present in one of nine TABLE 2 Postoperative Liver Scans : Correlation with Operative, Post-Mortem and Clinical Findings
Operative or autopsy findings Clinically evident Confirmed -____ Other liver Normal Metastases pathology metastases
Scan results Normal 149 Abnormal 45
18
17
I
10
6
4
0 0
0
4
patients with liver metastases and normal liver scans, and in ten out of 14 patients with metastases and abnormal liver scans. Postoperative liver scans were performed in 103 patients on 194 occasions, but in only 28 patients was confirmation obtained within the specified time (seven reoperations, 21 autopsies). The results are summarized in Table 2. One patient in 18 (5'5%) had a false-negative liver scan, but six patients out of ten (60%) had a false-positive scan. The TABLE 3 Correlation of Scan Results with Operative and Post-Mortem Findings No. Truenegative True positive False-negative False-positive
..
. . 78 .. 18 .. 10 .. 18 124
Overall accuracy Overall error
Percent 62'9
14'5 8.1 14.5
-
100'0
77.4% 22.6%
single patient with metastases and a normal scan did not have clinical evidence of liver metastasis, but all four patients with metastases and abnormal scans showed definite clinical features of spread to the liver. Combining both the preoperative and postoperative scans, the overall accuracy of the liver scan in correctly predicting the presence or absence of liver metastases for large-bowel
77
LIVER SCANNING IN COLORECTAL CARCINOMA
cancer was 77*4%, with a false-negative rate of 8.1% and a false-positive rate of 14.5% (Table 3). The outcome in 35 patients whose postoperative liver scans showed focal defects is shown in Table 4. I n 13 patients (37'1%) the subsequent scans became normal. In 14patients TABLE4 Postofierativc Abnormal Liver Scans
No. of patients Abnormal scans Subsequent normal scans Hepatic arteriography : Recommended . . . . . . Refused Performed . . . . Findings . .
:
The SAP was determined in 222 patients before operation. The results of this and the operative and clinical findings are listed in Table 5 . Four patients who had liver lesions other than metastases were excluded from calculation of percentages. I n 21 patients out of 186 patients with normal SAP levels, metastases were found-a false-negative rate of 11.3%. On the other hand, eight out of 32 patients with elevated SAP levels were free of metastases-a false-positive rate of 25.0%. TABLE6 Correlation of S A P Results with Operative Findings
2%
WONG AND ONG
LIVER SCANNING IN PATIENTS WITH COLORECTAL CARCINOMA J O H N WONG AND G. B. ONG Department of Surgery, University of Hong Kong, Queen Mary Hospital, Hong Kong
Three hundred l i v e r scans were performed o n a routine basis in patients with colorectal carcinoma, before and after operation, t o detect hepatic metastases. In 98 o f 106 preoperative and 28 of 194 postoperative scans, confirmation of the pathological condition was obtained a t operation o r post-mortem examination. T h e overall diagnostic accuracy of the scan was 77.4%, b u t the false-positive rate was high. T h e presence of focal defects in l i v e r scans before operation did n o t influence our decision regarding abdominal exploration. A f t e r operation 'on patients who did n o t have disseminated disease and whose liver scans showed localized focal defects, selective hepatic arteriography and abdominal exploration did not reveal resectable metastatic disease. In one-third of patients w i t h abnormal l i v e r scans after operation, subsequent scans returned t o normal. O f the patients w i t h t r u e positive liver scans, three-quarters had clinically evident hepatic metastases. Serum alkaline phosphatase estimations were as accurate in detecting liver metastases as the liver scan, and returned fewer false-positive results. Routine l i v e r scanning before o r after operation i s n'ot recommended f o r patients w i t h colorectal carcinoma and should be reserved f o r patients w i t h clinical features o r biochemical abnormalities suggestive o f l i v e r metastases.
THE value of radioisotope scanning in the diagnosis of focal or diffuse diseases in the liver appears established. There is disagreement, however, in the diagnostic accuracy and therefore in the clinical usefulness of this investigation in detecting hepatic metastases (Smith and Williams, I@S; Ariel et alii, 1969; Poulose et alii, 1969; Castagna et alii, 1972; du Priest et alii, 1973; Ranson et alii, 1973; Rosenthal and Kaufman, 1973). This discrepancy in results may be partly due to the inclusion, in most reported series, of diverse types of primary carcinomas as well as sarcomas and lymphomas, which renders the interpretation of results less exact. Routine liver scanning before and after operation has been advocated by Poulose eb a& (1969) and Andrews et alii (1973) in order to detect unsuspected hepatic metastases and so help in planning appropriate therapy. The purpose of this study has been to assess the accuracy of the liver scan when only patients with carcinoma of one part of the Reprints : Dr John Wong, address as above.
76
gastrointestinal tract, the large bowel, are included, and to determine the value of routine liver scanning in the management of the patient before and after operation. This paper reports the results of 300 liver scans performed in 201 patients with colorectal cancers. The accuracy of serum alkaline phosphatase estimations and clinical assessment in detecting hepatic metastases has also been compared with that of the liver scans.
PATIENTS AND METHODS Between 1971 and 1975, patients admitted to the University Surgical Unit, Queen Mary Hospital, Hong Kong, with a diagnosis of colorectal carcinoma, were included in the study for preoperative liver scanning. Two groups of patients were excluded: those presenting with acute complications requiring immediate operation, and those who had to wait more than four weeks for the scan examination. The liver scan was performed by a Phillips rectilinear scanner using 113 m indium colloid. Usually only the anterior view was recorded unless the scan was abnormal, when a lateral view was aIso obtained. AUST. N.Z. J. SURG.,
VOL.
47-NO.
I,
FEBRUARY, 1977
LIVER SCANNING I N COLORECTAL CARCINOMA
The liver scan was classified as normal or abnormal according to the .official interpretations made at the time the examination was performed. I t was considered normal if it was read as normal or if it showed diffuse nonuniform uptake without focal lesions. It was considered abnormal if focal defects were reported, irrespective of the nature of radioisotope uptake in the rest of the liver. At operation the liver was examined for evidence of metastatic or other disease. Small peritoneal seedlings on the liver surface in the absence of intrahepatic deposits were not included as hepatic metastases. After operation patients were scanned at half-yearly to yearly intervals. Patients who did not have preoperative liver scans were also included. These patients comprise those who presented with acute complications, those who would otherwise have had a long delay before operation, and those referred to our Unit after surgery. If the scan was abnormal, the examination was repeated. If this abnormality TABLE I Preoperative Liver Scans : Correlation with operative and Clinical Findings Operative findings
Scan results
Confirmed
Normal 76 Abnormal 30
71 27
Clinically evident Other liver Normal Metastases pathology metastases
61 I2
9
' 4
I* I**
I I0
* Cirrhosis. ** Recurrent pyogenic cholangitis.
persisted and unilobar hepatic metastasis was suspected, hepatic arteriography was performed. If scan and arteriographic findings both suggested localized disease, exploration with a view to hepatic resection was recommended to the patient. Only scans performed within one month of operation or post-mortem examination were regarded as confirmed. The clinical criteria for the diagnosis of hepatic metastases included hepatomegaly of at least 7 cm and associated with induration, tenderness or nodules (Fenster and Klatskin, 1961). The serum alkaline phosphatase level (SAP) was estimated in all patients before operation, A figure of 15 King-Armstrong units/roo ml or more was regarded as elevated (the normal figure is less than 13 units/Ioo ml in our laboratory). AUST. N.Z. J. SURG.,VOL.47-No.
I,
FEBRUARY, 1977
WONG AND ONG
RESULTS Preoperative liver scans were performed in 106 patients with large-bowel cancers. Table I shows the correlation of scan results with operative and clinical findings. In nine patients out of 71 with normal scans, metastases were found-a false-negative rate of 12.6%. On the other hand, 12 out of 27 patients with abnormal liver scans had normal livers - a false-positive rate of 44.4%. Clinically evident liver metastasis was present in one of nine TABLE 2 Postoperative Liver Scans : Correlation with Operative, Post-Mortem and Clinical Findings
Operative or autopsy findings Clinically evident Confirmed -____ Other liver Normal Metastases pathology metastases
Scan results Normal 149 Abnormal 45
18
17
I
10
6
4
0 0
0
4
patients with liver metastases and normal liver scans, and in ten out of 14 patients with metastases and abnormal liver scans. Postoperative liver scans were performed in 103 patients on 194 occasions, but in only 28 patients was confirmation obtained within the specified time (seven reoperations, 21 autopsies). The results are summarized in Table 2. One patient in 18 (5'5%) had a false-negative liver scan, but six patients out of ten (60%) had a false-positive scan. The TABLE 3 Correlation of Scan Results with Operative and Post-Mortem Findings No. Truenegative True positive False-negative False-positive
..
. . 78 .. 18 .. 10 .. 18 124
Overall accuracy Overall error
Percent 62'9
14'5 8.1 14.5
-
100'0
77.4% 22.6%
single patient with metastases and a normal scan did not have clinical evidence of liver metastasis, but all four patients with metastases and abnormal scans showed definite clinical features of spread to the liver. Combining both the preoperative and postoperative scans, the overall accuracy of the liver scan in correctly predicting the presence or absence of liver metastases for large-bowel
77
LIVER SCANNING IN COLORECTAL CARCINOMA
cancer was 77*4%, with a false-negative rate of 8.1% and a false-positive rate of 14.5% (Table 3). The outcome in 35 patients whose postoperative liver scans showed focal defects is shown in Table 4. I n 13 patients (37'1%) the subsequent scans became normal. In 14patients TABLE4 Postofierativc Abnormal Liver Scans
No. of patients Abnormal scans Subsequent normal scans Hepatic arteriography : Recommended . . . . . . Refused Performed . . . . Findings . .
:
The SAP was determined in 222 patients before operation. The results of this and the operative and clinical findings are listed in Table 5 . Four patients who had liver lesions other than metastases were excluded from calculation of percentages. I n 21 patients out of 186 patients with normal SAP levels, metastases were found-a false-negative rate of 11.3%. On the other hand, eight out of 32 patients with elevated SAP levels were free of metastases-a false-positive rate of 25.0%. TABLE6 Correlation of S A P Results with Operative Findings
2%
