How accurate is angiographic staging of renal carcinoma?

Imaging approach to staging of renal cell carcinoma

Current imaging techniques, especially CT and MR imaging, make accurate preoperative staging of renal cell carcinoma possible. Because surgery provides the only effective therapy and because survival depends on local and distant extent, precise staging is critical for preoperative planning and prognosis. This article reviews the advantages, limitations, accuracy, and pitfalls of each of the imaging approaches to staging renal cell carcinoma, concentrating on CT and MR imaging. This information then is summarized in a suggested overall approach to staging renal cell carcinoma.

Analysis of imaging modalities, staging systems, and prognostic indicators for renal cell carcinoma

A retrospective analysis of 314 patients with renal cell carcinoma was done focusing mainly on imaging modalities and prognostic significance of tumor stage using both the Robson and TNM systems. Computerized tomography (CT) scan proved to be the most effective modality for staging. Overall staging accuracy was 62 and 68 percent for TNM and Robson staging, respectively, and understaging was more frequent than overstaging. The actuarial five-year survival using the Robson system was 73 percent for Stage A, 68 percent Stage B, 51 percent Stage C, and 20 percent Stage D. The main limitation of the Robson system is the heterogeneity of the Stage C group which includes patients with renal vein and those with nodal involvement with a significant difference in survival. The survival by the TNM system showed no difference in those with T1, T2, T3a and T3b disease but a significant difference in those with T3c or T4a. One hundred sixteen patients (37%) presented with metastatic disease with a median survival of seventeen months (range 2-204) for those with solitary metastasis and six months (range 1-132) for those with multiple metastases (the difference was not statistically significant). Except for anecdotal cases, nephrectomy with or without treatment of the metastases did not seem to affect survival significantly. The presence of spindle cell, alone or in association with clear or granular cell, affected the prognosis adversely. Thirty-one patients had their tumors identified incidentally. Their stage at diagnosis was earlier than the symptomatic group (Stage T1-T2: 77% vs 34%), and there was a significant difference in the disease-free survival at fifty-four months between the two groups (79% vs 57%, respectively).

Comparison of excretory urography, angiography, ultrasound and computed tomography for T category staging of renal cell carcinoma

The diagnostic significance of excretory urography, renal angiography, ultrasound and computed tomography for predicting the stage of tumours was evaluated by comparing their results with peroperative and histopathological findings. Thirty-nine out of 178 patients operated on for renal cell carcinoma from 1981 to 1988 were subjected to all four diagnostic procedures. The T stage was determined correctly by computed tomography in 80% of the cases, by ultrasound in 74.5%, by renal angiography in 64% and by excretory urography in 56.5%. Excretory urography did not give any significant additional information on the T category compared with the other imaging methods. Angiography is still of value in that it gives preoperative information on the collateral circulation and the number of renal arteries and their location.

Comparison of angiography and computed tomography using new morphologic criteria in staging of renal cell carcinoma

The staging of tumor extension, and regional lymph node and venous involvement by angiography and computed tomography (CT) using new morphologic criteria were compared with the surgical and histopathologic stage in 59 patients (60 cases) with renal cell carcinoma. A high degree of accuracy in staging of both angiography and CT was demonstrated. However, CT was more accurate and sensitive than angiography in the evaluation of tumor extension and regional lymph node involvement, and equally accurate in that of venous involvement. We emphasize that new morphologic criteria of angiography and CT are clinically useful, and CT is the primary approach for the staging of renal cell carcinoma.

Comparative value of ultrasonography, computerized tomography, angiography and excretory urography in the staging of renal cell carcinoma

From 1982 to 1985, 225 patients with renal cell carcinoma were treated by nephrectomy. To evaluate the diagnostic significance of ultrasonography in predicting tumor stage the results of ultrasonography, computerized tomography, renal angiography and excretory urography were compared to the histopathological findings. Since local tumor extension has a considerable impact on the operation strategy evaluation of the T classification was of particular interest. All 4 diagnostic procedures were performed in 73 of the 225 patients. The T stage was determined correctly by ultrasonography in 77.8 per cent of the patients, while the tumor was not identifiable in only 0.6 per cent. Computerized tomography was almost as reliable as ultrasonography (the T stage was predicted correctly in 72.3 per cent of the examinations). In contrast, the tumor was staged correctly by angiography in only 57.2 per cent of the patients and by excretory urography in only 59.2 per cent. From these results ultrasonography appears to be an effective, noninvasive, inexpensive and safe procedure to evaluate the T stage of renal tumors.

Role of computed tomography in staging of renal cell carcinoma

Accurate pre-operative staging of renal cell carcinoma is necessary to determine the surgical approach and prognosis. The advent of computed tomography has brought about a remarkable improvement in accuracy of pre-operative staging in such cases by non-invasive means. The role of computed tomography in staging of renal cell carcinoma has been evaluated in 28 cases and correlated with clinical and surgical findings.

Digital subtraction angiography in staging renal cell carcinoma: comparison with computerized tomography and histopathology

Digital subtraction angiography was compared to computerized tomography and histopathological findings for staging renal cell carcinoma in 24 patients. Injection of contrast material through a 16 gauge angiocatheter into the femoral vein provided digital subtraction cavography, digital subtraction arteriography and excretory urography during 1 investigation. Computerized tomography established the diagnosis in all patients, while digital subtraction angiography showed all angiographic signs of renal cell carcinoma in 14 (58 per cent). T staging was correct on computerized tomography in 18 patients and on digital subtraction angiography in 16. Absence or presence of venous involvement was indicated correctly by computerized tomography in 20 patients and by digital subtraction angiography in 21. In small tumors the combination of ultrasonography, digital subtraction angiography and excretory urography is sufficient for an operation. In all other tumors digital subtraction angiography cannot replace computerized tomography but adds useful information about arterial distribution, possible venous tumor thrombus and the anatomical relationship of vessels.

The diagnosis and local staging of renal cancer--an appraisal

The standard pattern of investigation for renal masses usually involves excretion urography, ultrasonography and angiography. This study was undertaken to determine whether computed tomography (CT) and fine needle aspiration cytology could provide information that might allow this pattern to be modified. Diagnostic information was obtained by needle aspiration cytology in 25 patients who were shown at operation to have a neoplasm. The diagnosis was correct in 22 cases (88%). By comparison, arteriography was accurate in 22 out of 24 (92%), and computed tomography provided the correct diagnosis in 19 out of 21 (90%). Staging was performed surgically and histologically in 21 patients, and when this was compared with the results of CT staging there was complete agreement in 13 cases (62%). A literature review revealed an average staging accuracy for CT of 81% while arteriography was accurate in only 57%. Thus CT appears to be as good as arteriography for diagnosis and potentially better for local staging. It is also less invasive, rapid and cost effective and could supersede arteriography as the primary diagnostic and staging investigation in patients with a solid renal mass.

Digital subtraction angiography in the preoperative evaluation of patients with a renal tumor

Inguinal intravenous digital subtraction angiography (DSA) was performed in 14 patients referred for preoperative evaluation of a renal tumor previously diagnosed by CT and ultrasound. Conventional cavography and aortography were used as reference methods for comparison. Both DSA and conventional angiography were carried out following selective arterial injection to the abnormal kidney. The diagnostic value of DSA in examination of the inferior vena cava was generally comparable to that of conventional cavography. Intravenous aortography was unsuccessful in 2 patients due to motion artifacts. In all other patients, the information provided by DSA regarding the aorta, renal arteries and renal veins was similar to that of conventional aortography. Intrarenal vascular detail, however, was far superior on conventional films and was only useful with DSA when intra-arterial injection was implemented. In one of the 12 diagnostic examinations, localization of the renal mass could not be established by intravenous DSA, but was possible in all others. The inguinal approach advocated permits simultaneous inferior vena cavography and intravenous aortography with one single injection of contrast medium; the method is less traumatic than aortography , and does not require hospitalization of the patient. DSA may also be of value in those cases still requiring selective catheterization of the renal arteries, i.e. for angiotherapy . Intra-arterial DSA then allows reduction of the amount of contrast medium and a rapid processing of the images without detriment to the quality of the examination.

Oncologic imaging: kidney and ureter

Malignant cancers of the kidney and ureter account for only 2-3% of all neoplasms in man. However, early diagnosis and treatment can have a profound effect on patient prognosis and survival. This article seeks to amalgamate a large body of information related to the pathology or primary renal tumors and metastatic disease with current imaging strategies to assist the clinician and enhance his understanding of the wide variety of modern imaging techniques available. Current tumor staging classifications are presented and the various imaging strategies are keyed to detection, definition and treatment options for tumors of the renal parenchyma and ureter. The strengths and limitations of all available imaging modalities are reviewed. An optimal approach to the imaging work up is developed with regard to availability, evolving technology and most importantly, cost efficacy. The controversies and conflicts in imaging and treatment options are explored while constructing a step by step approach that will be both flexible and utilitarian for the clinician faced with daily oncologic management choices.

Accuracy of computed tomography in staging of kidney tumors

Computed tomography was performed in 125 patients with kidney tumors for pretreatment staging. The accuracy of CT staging was then determined by correlating the CT findings with the pathologic findings (111 patients) or with the angiographic findings (14 patients). Perirenal extension was correctly predicted in 79 per cent of all the patients, lymph node involvement in 87, main renal vein involvement in 91, infiltration of the inferior vena cava in 97 and invasion of neighboring organs in 96 per cent. It is concluded that CT should be the baseline procedure for the assessment of the extent of spread of renal tumors.

Computed tomography, angiography and ultrasound in staging of renal carcinoma

Preoperative evaluation of the extent of the renal tumor is of value in determining the prognosis of the patient and the most suitable therapy. CT and angiography were reviewed in 27 cases of renal carcinoma to evaluate tumor involvement of lymph nodes, renal vein, vena cava, and the perinephric space. In 26 of these cases the ultrasound examination was similarly reviewed. Comparison of ultrasound, CT, and angiography demonstrated that staging of renal tumors with ultrasound is mainly limited by its inability to demonstrate extrarenal infiltration. Both CT and ultrasound proved reliable in the demonstration of tumor spread to the renal vein and inferior vena cava. CT and angiography were equally effective in the evaluation of tumor extension; since CT is easier to perform, less invasive and less time consuming than angiography it should be the primary method for staging of renal neoplasms. Angiography offers detailed information on the vascular supply of the tumor important for the choice of surgical approach and should be performed only on special indications.