Upsala J Med Sci 90: 101-106, 1985 Peroperative Staging of Renal Carcinoma A methodologic comparison d;ke Fritjofsson, Anders Hemmingsson, Per Gunnar Lindgren and Stig Reinholdsson Departments of Urology and Diagnostic Radiology, Uniwrsity Hospital, Uppsala, Sweden ABS T RAC 1 Angiography, computed tomography and ultrasonography were compared with re- spect to staging of renal carcinoma in 41 patients with 46 renal tumours. Angi- ography and ultrasonography gave correct staging in 52 L and 48 %, respective- ly, while correct staging was achieved with computed tomography in 80 5 of the tumours. INTRODUCTION Staging is one of the fundamental guidelines for t h e management and prog- nostic evaluation of neoplasms, including renal cancer. Critical factors for accurate clinical staging of renal carcinoma are extension through the renal capsule with invasion of perinephric fat, invasion of Gerota’s fascia or ad- jacent organs, thrombotic tumour extension into the renal vein o r inferior vena cava, involvement of regional lymph nodes and general dissemination. Urography and angiography currently are basic procedures in the diagnosis of renal carcinoma. Assessment of perirenal tumour extension and of local metastas- ization with these methods often is uncertain, however ( 6 ) . On the other hand, selective injection of a large dose of contrast medium into the renal artery ( Z ) , possibly supplemented with cavography ( 9 ) gives high diagnostic reliabil- ity with respect to extension of tumour to the renal vein o r inferior vena cava. In recent years the noninvasive techniques of computed tomography ( 1 , 6 , 7 , 1 2 , 15) and ultrasonography (3,4) have also been used in the diagnosis of renal tumours. The present report concerns the possibilities for correct preoperative (clinical) staging of renal carcinoma by means of renal angiography (RA), com- puted tomography (CT) and ultrasonography ( U S ) . In a series of patients, the findings at these examinations were compared with observations made by the surgeon and/or pathologist. 101 MATERIAL AND METHODS The series comprised 41 patients with renal carcinoma investigated in the period December 1977 - June 1902. There were 20 men and 13 women, with mean age 6 0 . 2 (range 34-73) years. Five of the patients had bilateral carcinoma. The total of investigated kidneys thus was 4 6 , involving the right kidney in 28 cases and the left in 18. In 38 patients extrafascial nephrectomy o r , when there was bilateral disease, kidney resection was performed. The other three patients died soon after diagnosis and were studied post mortem. F o r staging of the tumours we used a modification of the classification pro- posed by Robson et al. (ll), as shown in Table 1. The study was restricted to clarification of the intraabdominal extent o f t u m o u r , and disseminated or dist- ant metastases were disregarded in the present connection. Table 1. Staging classification of renal adenocarcin- oma according to Robson et al. (11) Stage Tumour I within kidney capsule I1 invading perinephric fat (confined to 111 a involving renal vein o r inferior vena I11 b involving regional lymph nodes involving renal vein o r vena cava and I11 a + b regional lymph nodes IV invading adjacent organ(s) Gerota’s capsule) cava - R A and CT were performed in all cases, and 35 tumours were also studied with us. RA was performed with conventional technique, injecting contrast medium into the aorta and selectively into the renal arteries. Evaluation of the renal vein was facilitated by injection of 30-50 m l Angiografin (306 mg I/m1) selectively into the renal artery. On any suspicion of tumour thrombus in the renal vein, cavography was performed with standard technique. For CT a Delta 50 FS scanner (Ohio Nuclear) was used, with exposure time 18 s, slice thickness 13 mm and beam width 5 mm. CT scanning was performed over R the kidneys before and after intravenous injection of contrast medium (Conray meglumine, 282 mg I/ml). US over the kidneys was performed in the first 2 years with a Sono Diagriost 102 B 50 (Philips) grey-scale apparatus, and after 1979 we used an ATL Mark I11 dynamic sector-scan apparatus with a 3.0 MHz transducer. I 22 19 I1 5 4 RESULTS ~~ ~~ ~ 1 1 1 1 In Table 2 the pathologic and angiographic stagings are compared. Stage I tumours were correctly evaluated with RA in most patients, while more advanced tumours often were understaged. RA correctly staged the tumour in altogether 52 7; of the cases, with understaging in 41 E and overstaging in 7 E Table 2. pathology staging Angiographic staging of renal tumours compared with Operation/autopsy Renal angiography group n I I1 IIIa IIIb IIIa+b IVa IVa 10 1 1 4 Total 46 30 4 7 5 Understaging 19/46 (41 76) Overstaging 3/46 ( 7 7;) Correct staging 24/46 (52 % ) With US the tumour staging was correct in only 48 E of cases (Table 3 ) , mainly in stage I. There was 9 7; overstaging and 43 76 understaging. Difficult- ies in demonstrating local tumour involvement were encountered at US mainly when there was extension of tumour in dorsal direction. CT (Table 4) gave correct staging in 80 L of the tumours, but understaging in 11 % and overstaging in 9 L. CT thus was superior to the other procedures in providing information not only of the extent of tumour within the kidney, but also concerning its relations to the perinephric fat and adjacent orqans. More- over, CT was better than the other methods in detection o f nodal metastases. In the course o f this study we received a strong impression that CT in many cases can obviate the need for angiography in the preoperative diagnosis and staging of solid renal tumours. 103 Table 3. pathology staging Ultrasonographic staging o f renal tumours compared with I 17 2 L14 I1 4 1 1 1 2 IVa 6 2 2 1 IIIa 2 1 1 IIIb 4 3 Total 35 3 21 6 2 3 Understaging 15/35 (43 % ) Overstaging 5/35 ( 9 7 6 ) Correct staging 17/35 (48 5) 1 Table 4. pathology staging Computed tomography staging o f renal tumours compared with I 2 2 1 18 I 1 5 1 2 1 3 1 IIIa 3 2 1 IIIb 4 3 1 3 IIIa+b 2 2 IVa 10 10 DISCUSSION The results of this study showed CT to be the most reliable method for stag- ing of renal carcinoma with respect both to perirenal extension of the tumour and to presence of local metastases. Understaging was recorded in 41 % of the tumours at RA and in 43 5 at US. The inadequacy of angiography and ultrasono- graphy for staging of these renal tumours accords with previous experience (5, 6,lO). F o r evaluation of tumour growth to the liver, real-time US is valuable, and movements of surrounding tissues in relation to the tumour can be assessed, especially on deep expiration and inspiration. CT overstaged the tumour in four cases (9 :A). The reason was that these tu- mours lay against adjacent structures and could not be clearly separated from them at CT. Enhanced diagnostic accuracy with CT in such cases may be expected from the more modern equipment that permits rapid serial imaging after a bolus injection of contrast medium, thinner slices and higher spatial resolution. Turnour thrombi in the renal vein and vena cava can be detected both with CT (3,4,7,14) and with US (3,4). In the present series venous thrombi were found in only five cases, but subsequent experience has confirmed these diagnostic possibilities. Venography, however, is often valuable if tumour thrombus in the caval vein is visualized by US o r CT, to define the cranial limit of the thromb us preoperatively (8,13). Computed tomography thus permits more accurate staging of renal carcinoma than do renal angiography and ultrasonography as regards both perirenal ex- tension o f turnour growth and presence of local metastases. With computed tomo- graphy, however, there is a tendency to overstaging. Ultrasonography can be useful especially for judging the relation o f the tumour t o the liver when the tumour is located in the upper part of the right kidney. ACKNOWLEDGEMENT This investigation was supported by grants from t h e Swedish Cancer Society. 1. 2 . 3. REFERENCES Baert, A.L., Marchal, G . , Staelens, B. & Coenen, Y.: CT. Evaluation of renal space-occupying lesions. Fortschr Rontgenstr 126:285,1977. Bjijrk, F . , Erikson, U., Falk, J., Lindblad, G. & Stenport, G.: Clinical and histological studies on the effect o f large doses of roentgen contrast media in renal arteriography. Ups J Med Sci 80:46,1975. Goldstein, H.W., Green, B. & Weaver, R.M.Jr: Ultrasonic detection o f renal tumor extension into the inferior vena cava. Am J Roentgenol 130:1083,1978. 105 4. 5. 6. 7. 8. 9. 10. 11. 1 2 . 13. 1 4 . 15. Green, D. & S t e i n b a c h , H.L.: U l t r a s o n i c d i a g n o s i s o f hypernephroma e x t e n d - i n g i n t o t h e i n f e r i o r vena cava. R a d i o l o g y 115:679,1975. L a c k n e r , K . , K o i s c h w i t z , D., M o l i t o r , B., Vogel, J. & Schmidt, S . : T r e f f - s i c h e r h e i t i n d e r D i a g n o s t i k r e n a l e r Raumforderungen. Computer-tomographie, Sonographie, U r o g r a p h i e , A n g i o g r a p h i e . F o r t s c h r R o n t g e n s t r 140:363,1984. Love, L . , C h u r c h i l l , R., Reynes, C., S c h u s t e r , G.A., Moncada, R. & Berkow, A . : Computed tomography s t a g i n g o f r e n a l carcinoma. Urol R a d i o 1 1:3,1979. Marks, W.M., K o r o b k i n , M.,Callen, P.W. & K a i s e r , J.A.: C T d i a g n o s i s o f tumor t h r o m b o s i s o f t h e r e n a l v e i n and i n f e r i o r vena cava. Am J Roentgenol 131:843,1978. McCullough, D.L. & G i t t e s , R.F.: Vena cava r e s e c t i o n o f r e n a l c e l l c a r c i n - oma. J U r o l 112:162,1974. McMoy, R.M., K l a t t e , E.C. & Rhamy, R.K.: Use o f i n f e r i o r venacavography i n t h e e v a l u a t i o n o f r e n a l neoplasm. J U r o l 102:566,1969. P i l l a r i , G . , Lee, W.J., Kumari, S . , Chen, M., Abrams, H.J., B u c h b i n d e r , M . & S u t t o n , A.P.: C T and a n g i o g r a p h i c c o r r e l a t e s : S u r g i c a l image o f r e n a l mass l e s i o n s . U r o l o g y 17:296,1981. Robson, C.J., C h u r c h i l l , B.M. & Anderson, W . : The r e s u l t s o f r a d i c a l nephrectomy f o r r e n a l c e l l carcinoma. J Urol 101:297,1969. Sagel, S . S . , S t a n l e y , R.J., L e v i t t , R . G . & Geisse, G.: Computed tomography o f t h e k i d n e y . R a d i o l o g y 124:359,1977. S k i n n e r , D.G., P f i s t e r , R.F. & C o l v i n , R . : E x t e n s i o n o f r e n a l c e l l c a r c i n - oma i n t o t h e vena cava: t h e r a t i o n a l e f o r a g g r e s s i v e s u r g i c a l management. J Urol 107:711,1972. S t e e l e , J.R., Sones, P.J. & H e f f n e r , L.T. Jr: The d e t e c t i o n o f i n f e r i o r vena cava t h r o m b o s i s w i t h computed tomography. R a d i o l o g y 128:385,1978. S t r u y v e n , J . , B r i o n , J . P . , F r e d e r i c , N. & Schulman, C.C.: Computed tomo- graphy o f t h e k i d n e y . B r J U r o l 49:583,1977. Address f o r r e p r i n t s Ake F r i t j o f s s o n Department o f U r o l o g y U n i v e r s i t y H o s p i t a l 5-751 85 Uppsala Sweden 106