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Computerized Tomography Scan for Diagnosis and Staging of Renal Cell Carcinoma
0022-534 7/83/1296-1114$02.00/0
Vol. 129, June Printed in U.S. A.
THE JOURNAL OF UROLOGY
Copyright© 1983 by The Williams & Wilkins Co.
COMPUTERIZED TOMOGRAPHY SCAN FOR DIAGNOSIS AND STAGING OF RENAL CELL CARCINOMA JEROME P. RICHIE,* MARC B. GARNICK, STEVEN SELTZER
AND
MICHAEL A. BETTMANN
From the Departments of Surgery/Urology, Medical Oncology and Radiology, Harvard Medical School, Brigham and Women's Hospital and Sidney Farber Cancer Center, Boston, Massachusetts
ABSTRACT
A comparison of computerized tomography and arteriography for the diagnosis and staging of renal cell carcinoma was done in 45 patients during a 2-year interval. Compared to arteriography, computerized tomography was more accurate in the diagnosis of renal cell carcinoma (95 versus 85 per cent), equivalent in the determination of renal vein involvement and superior in the determination of regional nodal involvement. Because of the increased diagnostic accuracy, better delineation of the local extent of the tumor and less invasive nature we recommend computerized tomography as the preferred procedure for diagnosis and staging of renal cell carcinoma. However, in patients with questionable findings arteriography and/or inferior venacavography should be used as complementary studies. Controversy exists about the optimal and most cost-effective approach to the diagnosis of a renal mass. Flush and selective arteriographic examinations have been the sine qua non for accurate diagnosis and staging ofrenal cell carcinoma. However, these techniques are relatively invasive, carry a certain morbidity and have proved to be of limited value in the detection of extrarenal spread and regional nodal involvement. Improvements in computerized tomography (CT) scanning, with its advantages over other imaging modalities, have led to comparisons of CT and angiography in the diagnosis and staging of renal cell carcinoma. We have evaluated 45 patients with proved renal cell carcinoma to determine the effectiveness of arteriography and/or CT scan for accurate diagnosis and staging of the disease. MATERIALS AND METHODS
Results of preoperative diagnosis and staging by arteriogram and/or CT scan were available in 45 patients with renal cell carcinoma who underwent radical nephrectomy at our hospital between 1979 and 1981. All studies were reviewed prospectively and staging information was garnered from the official written reports rather than from retrospective review of the films. Inferior or superior venacavography also was performed in some patients. Arteriography routinely consisted of flush and selective runs, with or without the addition of pharmacologic agents such as epinephrine. All patients were operated upon within 2 weeks of staging studies. Routine metastatic evaluation included whole lung tomography, liver function tests and, often, radionuclide liver-spleen or bone scans. Patients with known metastases (stage IV), in whom radical nephrectomy was performed for palliation or in preparation for additional therapy, also had preoperative CT scans or arteriograms to document the local spread of tumor and are included in the analysis. CT scans were performed with a Technicare 2010 unit with a 2-second scan time. Images with a 10 mm. tissue thickness were obtained at 1 cm. intervals from the diaphragm to the symphysis pubis. CT and/ or arteriography studies done at other institutions were available for interpretation before therapy in a few patients. Staging was based upon the work of Robson and associates: 1 stage I-tumor confined within the kidney capsule, stage IIAccepted for publication October 8, 1982. Read at annual meeting of American Urological Association, Kansas City, Missouri, May 16-20, 1982. Supported in part by Brigham Surgical Group Foundation, Inc. * Requests for reprints: 75 Francis St., Boston, Massachusetts 02115.
tumor invasion through the renal capsule but the tumor is confined within Gerota's fascia, stage III-tumor involvement of regional lymph nodes, renal vein or inferior vena cava and stage IV-direct invasion of adjacent organs and/or metastasis to distant sites, including the lung, bone, brain, thyroid, adrenal and liver. RESULTS
Diagnosis. Renal cell carcinoma may be suspected on excretory urography (IVP) or ultrasound but further tests are necessary to establish the diagnosis. Arteriographic criteria for renal cell carcinoma have been well described and include corkscrew vessels, tumor blush, arteriovenous shunting and vascular puddling of contrast medium. 2 Arteriograms were performed preoperatively on 34 patients. Of the 34 patients confirmed to have renal cell carcinoma at operation 29 were believed to have renal cell carcinoma on the basis of arteriography and in 5 the diagnosis could not be made because of avascularity of the lesions. All 5 of these patients had a preoperative diagnosis of renal cell carcinoma based on a subsequent CT scan. CT predicted correctly the diagnosis of renal cell carcinoma in 38 of 40 patients. Criteria included the presence of a solid mass with a high attenuation coefficient (>40 HU) invading and distorting the renal parenchyma. There were 2 instances of mistaken diagnosis: a multilocular cyst in 1 and a hematoma found at operation in 1. Neither patient had undergone preoperative arteriography. Thus, the diagnostic accuracy of arteriography was 85 per cent, with a false negative rate of 15 per cent and a false positive rate of O per cent. The diagnostic accuracy of CT scanning was 95 per cent, with a false negative rate of O per cent and a false positive rate of 5 per cent. Of 29 patients who underwent CT and arteriography the correct diagnosis was established in 24 by arteriography and in 29 by CT scan. Staging. The ability of CT scan or angiography to stage accurately patients with renal cell carcinoma is given in the table. Patients were divided into those with tumors confined to the kidney (stage I), perinephric invasion (stage II) or regional lymph node, renal vein, inferior vena cava or hepatic involvement. Ten patients had stage I carcinoma on pathologic examination. CT diagnosed correctly stage I tumors in all patients, while angiography was accurate in 90 per cent. One patient whose disease was diagnosed as stage I by angiography proved to have stage II tumor at pathologic examination.
1114
COlv1i.3TJTERIZED TOlVIOGRAPHY .SC_lli"T OF ?t(EN.AL CELL CP..,.RCINOlvlA
CT versus angiography Stage: I II Regional lymph nodes Renal vein Inferior vena cava Liver involvement
1115
diagnosis and staging
No. Pts.
CT
(%)
Angiography
(%)
10 6 10 8 8 3
7/7 5/6 9/10 6/8 5/6 2/3
(100)
9/10
(90)
(83)
3/4
(75)
(90) (75)
4/6 5/6 6/6 1/3
(67)
(83) (66)
(83) (100)*
(33)
* Includes inferior venacavogram.
Six patients had stage II tumors on pathologic examination. Stage II tumors were predicted correctly by CT in 5 of 6 patients and by angiography in 3 of 4. The disease was misdiagnosed by both modalities in l patient with microscopic tumor extension into the perinephric space. CT scanning was superior in the diagnosis of lymphadenopathy. CT correctly diagnosed regional lymphadenopathy in 9 of 10 patients, while angiography suggested involvement in 4 of 6. CT could delineate better the exact location and site of regional lymph node involvement, and the relationship of the lymph nodes to other organs or the great vessels. Angiography was slightly more accurate than CT scanning in the diagnosis of renal vein involvement but not significantly different. Renal vein involvement was diagnosed correctly by angiography in 5 of 6 patients and by CT in 6 of 8. Inferior vena cavB1 involvement was diagnosed more accurately by angiography, including inferior venacavography. However, CT scanning suggested the correct diagnosis in 5 of 6 patients (fig. 1). Hepatic involvement was documented in 3 patients: CT scanning in 2 and arteriography in L Contralateral renal involvement was rare but in l patient, in whom both modalities were performed without the radiologist having knowledge of the results of the other test, both tests demonstrated the lesion correctly in the contralateral kidney (fig. 2).
FIG. 1. CT scan shows tumor thrombus inside inferior vena cava (arrow).
DISCUSSION
The detection of asymptomatic masses occurs with ever increasing frequency. Many of the lesions can be excluded as benign cysts based upon the appearance of the mass on an IVP with nephrotomography and ultrasound. Diagnostic accuracy of ultrasound approaches 95 to 98 per cent in distinguishing renal cysts from solid lesions. 3 However, the next step after depiction of a solid intraparenchymal lesion remains controversial. Not must the diagnosis be established but accurate staging is imperative to guide the surgical Arteriography may be 1m,,m,ctcuu;:; and to diagnose renal cell carcinoma. An estimated 5 to 10 per cent of the ,-,--"""'"·with renal cell carcinoma have avascular or sions that lack distinctive angiographic criteria. abscess, granuloma, xanthogranulomatous ~Rnn-,n~ or angiomyolipoma may simulate the angiographic criteria for renal cell carcinoma. 4 Arteriography requires hospitalization and the cost (with additional costs for each additional run) generally exceeds that of a CT scan 200 to 300 per cent (exclusive of hospitalization costs). The complication rate for arteriography is small. In a survey of> 11,000 transfemoral arteriograrns Lang reported a major complication rate of 0.7 per cent, a minor complication rate of 2.9 per cent and a mortality rate of 0.07 per cent, with deaths occurring only in high risk patients. 5 Digital subtraction angiography is a recent addition to the uroradiological armamentarium. Although this technique with intravenous injection and computer enhancement accurately shows the main renal arteries, depiction of peripheral intrarenal vessels is limited and probably ineffective in establishing the fine structural details of tumor vascularity. CT scanning, an outpatient procedure, has proved more effective than arteriography in establishing the diagnosis of renal cell carcinoma. Furthermore, with proper attention CT
CT scan shows large tumor in right lddney but sn-iall B, selective arteriography with epinephrine (arrow).
can depict more accurately the stage of tumor and the presence or absence of retro peritoneal lymph nodes or inferior vena caval involvement. Weyman and associates compared CT scanning and angiography in 62 cases and reported that CT was more accurate over-all for staging of regional nodal involvement and equally accurate for prediction of renal vein or inferior vena caval involvement. 6 Similar conclusions were reached by Levine and associates. 7 Cronan and associates reported a 91 per cent accuracy rate for staging with CT compared to 61 per cent with arteriography. 8 As a result of these comparisons we believe that CT is the procedure of choice for diagnosis and preoperative staging (for local extent) of renal cell carcinoma. However, in patients with equivocal findings, inferior venacavography and/ or arteriography should be used as complementary studies.
1116
RICHIE AND ASSOCIATES
REFERENCES 1. Robson, C. J., Churchill, B. M. and Anderson, W.: The results of
nephrectomy for renal cell carcinoma. J. Urol., 101: 297, 1969. 2. Lang, E. K.: Roentgenographic assessment of asymptomatic renal lesions. An analysis of the confidence level of diagnoses established by sequential roentgenographic investigation. Radiology, 109: 257, 1973. 3. Smith, E. H. and Bennett, A. H.: The usefulness of ultrasound in the evaluation ofrenal masses in adults. J. Urol., 113: 525, 1975. 4. Meaney, T. F.: Errors in angiographic diagnosis of renal masses. Radiology, 93: 361, 1969.
5. Lang, E. K.: Complications of retrograde percutaneous arteriography. J. Urol., 90: 604, 1963. 6. Weyman, P. J., McClennan, B. L., Stanley, R. J., Levitt, R. G. and Sagel, S. S.: Comparison of computed tomography and angiography in the evaluation of renal cell carcinoma. Radiology, 137: 417, 1980. 7. Levine, E., Lee, K. R. and Weigel, J.: Preoperative determination of abdominal extent of renal cell carcinoma by computed tomography. Radiology, 132: 395, 1979. 8. Cronan, J. J., Zeman, R. K. and Rosenfield, A. T.: Comparison of computerized tomography, ultrasound and angiography in staging renal cell carcinoma. J. Urol., 127: 712, 1982.
Vol. 129, June Printed in U.S. A.
THE JOURNAL OF UROLOGY
Copyright© 1983 by The Williams & Wilkins Co.
COMPUTERIZED TOMOGRAPHY SCAN FOR DIAGNOSIS AND STAGING OF RENAL CELL CARCINOMA JEROME P. RICHIE,* MARC B. GARNICK, STEVEN SELTZER
AND
MICHAEL A. BETTMANN
From the Departments of Surgery/Urology, Medical Oncology and Radiology, Harvard Medical School, Brigham and Women's Hospital and Sidney Farber Cancer Center, Boston, Massachusetts
ABSTRACT
A comparison of computerized tomography and arteriography for the diagnosis and staging of renal cell carcinoma was done in 45 patients during a 2-year interval. Compared to arteriography, computerized tomography was more accurate in the diagnosis of renal cell carcinoma (95 versus 85 per cent), equivalent in the determination of renal vein involvement and superior in the determination of regional nodal involvement. Because of the increased diagnostic accuracy, better delineation of the local extent of the tumor and less invasive nature we recommend computerized tomography as the preferred procedure for diagnosis and staging of renal cell carcinoma. However, in patients with questionable findings arteriography and/or inferior venacavography should be used as complementary studies. Controversy exists about the optimal and most cost-effective approach to the diagnosis of a renal mass. Flush and selective arteriographic examinations have been the sine qua non for accurate diagnosis and staging ofrenal cell carcinoma. However, these techniques are relatively invasive, carry a certain morbidity and have proved to be of limited value in the detection of extrarenal spread and regional nodal involvement. Improvements in computerized tomography (CT) scanning, with its advantages over other imaging modalities, have led to comparisons of CT and angiography in the diagnosis and staging of renal cell carcinoma. We have evaluated 45 patients with proved renal cell carcinoma to determine the effectiveness of arteriography and/or CT scan for accurate diagnosis and staging of the disease. MATERIALS AND METHODS
Results of preoperative diagnosis and staging by arteriogram and/or CT scan were available in 45 patients with renal cell carcinoma who underwent radical nephrectomy at our hospital between 1979 and 1981. All studies were reviewed prospectively and staging information was garnered from the official written reports rather than from retrospective review of the films. Inferior or superior venacavography also was performed in some patients. Arteriography routinely consisted of flush and selective runs, with or without the addition of pharmacologic agents such as epinephrine. All patients were operated upon within 2 weeks of staging studies. Routine metastatic evaluation included whole lung tomography, liver function tests and, often, radionuclide liver-spleen or bone scans. Patients with known metastases (stage IV), in whom radical nephrectomy was performed for palliation or in preparation for additional therapy, also had preoperative CT scans or arteriograms to document the local spread of tumor and are included in the analysis. CT scans were performed with a Technicare 2010 unit with a 2-second scan time. Images with a 10 mm. tissue thickness were obtained at 1 cm. intervals from the diaphragm to the symphysis pubis. CT and/ or arteriography studies done at other institutions were available for interpretation before therapy in a few patients. Staging was based upon the work of Robson and associates: 1 stage I-tumor confined within the kidney capsule, stage IIAccepted for publication October 8, 1982. Read at annual meeting of American Urological Association, Kansas City, Missouri, May 16-20, 1982. Supported in part by Brigham Surgical Group Foundation, Inc. * Requests for reprints: 75 Francis St., Boston, Massachusetts 02115.
tumor invasion through the renal capsule but the tumor is confined within Gerota's fascia, stage III-tumor involvement of regional lymph nodes, renal vein or inferior vena cava and stage IV-direct invasion of adjacent organs and/or metastasis to distant sites, including the lung, bone, brain, thyroid, adrenal and liver. RESULTS
Diagnosis. Renal cell carcinoma may be suspected on excretory urography (IVP) or ultrasound but further tests are necessary to establish the diagnosis. Arteriographic criteria for renal cell carcinoma have been well described and include corkscrew vessels, tumor blush, arteriovenous shunting and vascular puddling of contrast medium. 2 Arteriograms were performed preoperatively on 34 patients. Of the 34 patients confirmed to have renal cell carcinoma at operation 29 were believed to have renal cell carcinoma on the basis of arteriography and in 5 the diagnosis could not be made because of avascularity of the lesions. All 5 of these patients had a preoperative diagnosis of renal cell carcinoma based on a subsequent CT scan. CT predicted correctly the diagnosis of renal cell carcinoma in 38 of 40 patients. Criteria included the presence of a solid mass with a high attenuation coefficient (>40 HU) invading and distorting the renal parenchyma. There were 2 instances of mistaken diagnosis: a multilocular cyst in 1 and a hematoma found at operation in 1. Neither patient had undergone preoperative arteriography. Thus, the diagnostic accuracy of arteriography was 85 per cent, with a false negative rate of 15 per cent and a false positive rate of O per cent. The diagnostic accuracy of CT scanning was 95 per cent, with a false negative rate of O per cent and a false positive rate of 5 per cent. Of 29 patients who underwent CT and arteriography the correct diagnosis was established in 24 by arteriography and in 29 by CT scan. Staging. The ability of CT scan or angiography to stage accurately patients with renal cell carcinoma is given in the table. Patients were divided into those with tumors confined to the kidney (stage I), perinephric invasion (stage II) or regional lymph node, renal vein, inferior vena cava or hepatic involvement. Ten patients had stage I carcinoma on pathologic examination. CT diagnosed correctly stage I tumors in all patients, while angiography was accurate in 90 per cent. One patient whose disease was diagnosed as stage I by angiography proved to have stage II tumor at pathologic examination.
1114
COlv1i.3TJTERIZED TOlVIOGRAPHY .SC_lli"T OF ?t(EN.AL CELL CP..,.RCINOlvlA
CT versus angiography Stage: I II Regional lymph nodes Renal vein Inferior vena cava Liver involvement
1115
diagnosis and staging
No. Pts.
CT
(%)
Angiography
(%)
10 6 10 8 8 3
7/7 5/6 9/10 6/8 5/6 2/3
(100)
9/10
(90)
(83)
3/4
(75)
(90) (75)
4/6 5/6 6/6 1/3
(67)
(83) (66)
(83) (100)*
(33)
* Includes inferior venacavogram.
Six patients had stage II tumors on pathologic examination. Stage II tumors were predicted correctly by CT in 5 of 6 patients and by angiography in 3 of 4. The disease was misdiagnosed by both modalities in l patient with microscopic tumor extension into the perinephric space. CT scanning was superior in the diagnosis of lymphadenopathy. CT correctly diagnosed regional lymphadenopathy in 9 of 10 patients, while angiography suggested involvement in 4 of 6. CT could delineate better the exact location and site of regional lymph node involvement, and the relationship of the lymph nodes to other organs or the great vessels. Angiography was slightly more accurate than CT scanning in the diagnosis of renal vein involvement but not significantly different. Renal vein involvement was diagnosed correctly by angiography in 5 of 6 patients and by CT in 6 of 8. Inferior vena cavB1 involvement was diagnosed more accurately by angiography, including inferior venacavography. However, CT scanning suggested the correct diagnosis in 5 of 6 patients (fig. 1). Hepatic involvement was documented in 3 patients: CT scanning in 2 and arteriography in L Contralateral renal involvement was rare but in l patient, in whom both modalities were performed without the radiologist having knowledge of the results of the other test, both tests demonstrated the lesion correctly in the contralateral kidney (fig. 2).
FIG. 1. CT scan shows tumor thrombus inside inferior vena cava (arrow).
DISCUSSION
The detection of asymptomatic masses occurs with ever increasing frequency. Many of the lesions can be excluded as benign cysts based upon the appearance of the mass on an IVP with nephrotomography and ultrasound. Diagnostic accuracy of ultrasound approaches 95 to 98 per cent in distinguishing renal cysts from solid lesions. 3 However, the next step after depiction of a solid intraparenchymal lesion remains controversial. Not must the diagnosis be established but accurate staging is imperative to guide the surgical Arteriography may be 1m,,m,ctcuu;:; and to diagnose renal cell carcinoma. An estimated 5 to 10 per cent of the ,-,--"""'"·with renal cell carcinoma have avascular or sions that lack distinctive angiographic criteria. abscess, granuloma, xanthogranulomatous ~Rnn-,n~ or angiomyolipoma may simulate the angiographic criteria for renal cell carcinoma. 4 Arteriography requires hospitalization and the cost (with additional costs for each additional run) generally exceeds that of a CT scan 200 to 300 per cent (exclusive of hospitalization costs). The complication rate for arteriography is small. In a survey of> 11,000 transfemoral arteriograrns Lang reported a major complication rate of 0.7 per cent, a minor complication rate of 2.9 per cent and a mortality rate of 0.07 per cent, with deaths occurring only in high risk patients. 5 Digital subtraction angiography is a recent addition to the uroradiological armamentarium. Although this technique with intravenous injection and computer enhancement accurately shows the main renal arteries, depiction of peripheral intrarenal vessels is limited and probably ineffective in establishing the fine structural details of tumor vascularity. CT scanning, an outpatient procedure, has proved more effective than arteriography in establishing the diagnosis of renal cell carcinoma. Furthermore, with proper attention CT
CT scan shows large tumor in right lddney but sn-iall B, selective arteriography with epinephrine (arrow).
can depict more accurately the stage of tumor and the presence or absence of retro peritoneal lymph nodes or inferior vena caval involvement. Weyman and associates compared CT scanning and angiography in 62 cases and reported that CT was more accurate over-all for staging of regional nodal involvement and equally accurate for prediction of renal vein or inferior vena caval involvement. 6 Similar conclusions were reached by Levine and associates. 7 Cronan and associates reported a 91 per cent accuracy rate for staging with CT compared to 61 per cent with arteriography. 8 As a result of these comparisons we believe that CT is the procedure of choice for diagnosis and preoperative staging (for local extent) of renal cell carcinoma. However, in patients with equivocal findings, inferior venacavography and/ or arteriography should be used as complementary studies.
1116
RICHIE AND ASSOCIATES
REFERENCES 1. Robson, C. J., Churchill, B. M. and Anderson, W.: The results of
nephrectomy for renal cell carcinoma. J. Urol., 101: 297, 1969. 2. Lang, E. K.: Roentgenographic assessment of asymptomatic renal lesions. An analysis of the confidence level of diagnoses established by sequential roentgenographic investigation. Radiology, 109: 257, 1973. 3. Smith, E. H. and Bennett, A. H.: The usefulness of ultrasound in the evaluation ofrenal masses in adults. J. Urol., 113: 525, 1975. 4. Meaney, T. F.: Errors in angiographic diagnosis of renal masses. Radiology, 93: 361, 1969.
5. Lang, E. K.: Complications of retrograde percutaneous arteriography. J. Urol., 90: 604, 1963. 6. Weyman, P. J., McClennan, B. L., Stanley, R. J., Levitt, R. G. and Sagel, S. S.: Comparison of computed tomography and angiography in the evaluation of renal cell carcinoma. Radiology, 137: 417, 1980. 7. Levine, E., Lee, K. R. and Weigel, J.: Preoperative determination of abdominal extent of renal cell carcinoma by computed tomography. Radiology, 132: 395, 1979. 8. Cronan, J. J., Zeman, R. K. and Rosenfield, A. T.: Comparison of computerized tomography, ultrasound and angiography in staging renal cell carcinoma. J. Urol., 127: 712, 1982.