Comparison of computerized tomography, ultrasound and angiography in staging renal cell carcinoma

Imaging in the staging of renal cell carcinoma

Imaging is extremely important in determining the type of surgery undertaken in patients with proven renal cell carcinoma. In this review, the strength and limitations of each of the relevant techniques are outlined, highlighting particularly the correlation between the imaging findings and the pathological staging. Over the past decade, CT has become the most widely used technique for staging renal cell carcinoma, partly due to the very high overall accuracy of up to 90% that has been achieved. MRI appears to have a similar overall accuracy to CT, whereas ultrasound is less accurate than CT or MRI in the overall staging of tumours. However, ultrasound is extremely accurate in identifying and localising the clinically important tumour extension into the intra-hepatic vena cava and right atrium and if local surgical practice requires only a knowledge of venous invasion, a technically adequate ultrasound examination may suffice. All techniques are unreliable in detecting early perinephric spread.

Multimodality approach to staging renal cell carcinoma

Renal imaging has dramatically improved since the introduction of ultrasound (US), computed tomography (CT), and most recently magnetic resonance (MR) imaging. US and MR imaging are ideal for patients with compromised renal function preventing administration of iodinated contrast material or those who have experienced reactions to contrast. Staging errors occur due to limitations in assessing microscopic tumor invasion of the renal capsule and perinephric fat, detecting metastatic deposits in normal sized lymph nodes and differentiating inflammatory hyperplastic lymph nodes from neoplastic ones. These limitations are shared by US, CT, and MR imaging. Vascular invasion by tumor can be evaluated by all imaging modalities including venography. The advantages and limitations of each examination will be presented.

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).

CT staging of renal carcinoma: a prospective comparison of three dynamic computed tomography techniques

Three dynamic computed tomographic methods used for staging of renal carcinoma in 70 patients are described and compared. Twenty-eight patients were examined using incremental dynamic scanning across the kidneys whilst infusing contrast via an arm vein (technique 1). Eighteen patients were staged using a single location dynamic scan sequence at the level of the renal hilum followed by an incremental sequence during an infusion of contrast into the femoral vein (technique 2). Twenty-four patients were examined using a single location sequence at the level of the renal veins and a rapid bolus incremental dynamic technique (technique 3). Technique 1 correctly staged 20 patients (72%) with 4 patients (14%) understaged and 4 (14%) overstaged, technique 2 correctly staged 11 (61%) patients with 3 (17%) overstaged and 4 (22%) understaged and technique 3 staged 17 (71%) correctly with 3 (13%) understaged and 4 (17%) overstaged. The techniques using single location scanning were more accurate in demonstrating tumour involvement of the renal vein and inferior vena cava but were less accurate in assessing extracapsular spread. Technique 3 was the most accurate in the diagnosis of lymph-node involvement. As accurate pre-operative knowledge of vascular involvement by tumour is more important to the surgeon than the presence of extracapsular spread, the combined single location and incremental scan technique is advocated.

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.

Staging of renal cell carcinoma by dynamic computed tomography: a prospective comparison of two techniques

Two dynamic computed tomographic methods used for staging renal carcinoma in 46 patients are described and compared. Twenty-eight patients were examined using an infusion technique during incremental dynamic scanning across the kidneys with contrast administered via an arm vein. Eighteen patients were staged using a technique comprising a single location dynamic scan sequence at the level of the renal hilum followed by an incremental sequence during an infusion of contrast into the femoral vein. When compared with overall pathological staging, the arm vein infusion technique correctly staged 20 patients (72%) with four patients (14%) understaged and four (14%) overstaged. The femoral vein infusion and single location dynamic scanning technique correctly staged 11 (61%) patients with three (17%) overstaged and four (22%) understaged. The femoral vein infusion with single location scanning was more accurate in demonstrating tumour involvement of the renal vein (83.3% correct vs. 78.6%), inferior vena cava (94.4% correct vs. 89.3%) and lymph nodes (88.9% correct vs. 78.6%) but was less accurate in assessing extracapsular spread (77.8% correct vs. 96.4%). The additional information obtained from the single location dynamic sequence is sufficiently valuable for this part of the second technique to be used in any scanning protocol for staging renal carcinoma.

A prospective study of the value of conventional CT, dynamic CT, ultrasonography and arteriography for staging renal carcinoma

The value of dynamic CT scanning for staging renal carcinoma was studied prospectively in 28 patients and the results compared with those of ultrasonography, arteriography and conventional CT. Arteriography correctly staged 48% of tumours; ultrasonography and conventional CT correctly staged 50% and dynamic CT correctly staged 72%. Dynamic CT staged renal carcinoma more accurately than ultrasonography, conventional CT or arteriography and it is suggested that arteriography should be restricted to specific indications such as the mapping of arterial anatomy and therapeutic renal artery embolisation.

Venous invasion in renal cell carcinoma: a correlative clinical and radiologic study

Angiography, cavography, ultrasound (US), computed tomography (CT), and low-field magnetic resonance imaging (MRI) were used to explore venous tumor invasion in 86 patients with renal cell carcinoma. The findings confirm previous experience that ultrasound and dynamic CT are reliable methods for the evaluation of venous invasion. Low-field magnetic resonance imaging does not improve tumor staging. In case of equivocal findings, vena cavography should be used as a complementary examination.

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.

Digital subtraction angiography of the kidney

Intravenous and intra-arterial digital subtraction angiography (DSA) was performed in 88 patients: 34 with tumours, 10 with renal trauma, 26 with suspected renovascular hypertension, 6 with vascular impression on the renal pelvis, 8 with nephrolithiasis and 4 with sonographically abnormal kidneys. Venous and arterial DSA always gave diagnostically useful images. Intravenous DSA is valuable in patients with suspected renovascular hypertension or after vascular surgery, percutaneous transluminal angioplasty and transcatheter embolisation. Arterial DSA is preferable to venous DSA in other clinical situations, particularly in the evaluation of renal tumours, and may be recommended in preference to conventional angiography.

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.

Renal mass imaging: the internist's role

The busy internist will encounter numerous renal masses when ordering nonurologic imaging. Concise and quick delineation of cystic from solid masses is necessary. Cystic masses constitute the majority of these masses and once their nature is diagnosed, they require no further work-up or referral. Often, a single imaging technique is unable to confidently establish the cystic nature of a renal mass. Proper selection of an additional imaging modality will often be successful in establishing the cystic characteristics of a benign mass. Referral to a urologist is not necessary in this setting, since the internist can coordinate the imaging evaluation with proper radiologic consultation. Alternatively, when a mass is determined to be solid, urologic consultation and surgical evaluation are necessary. Minimization of the imaging sequence and hospitalization are critical in the diagnostic-related group era. Aimless wandering in the quagmire of imaging techniques is very expensive and nonproductive. Proper selection of one or two imaging tools and occasionally needle puncture should produce clarification of the cystic or solid nature of renal mass. On the basis of our experience, we have designed an imaging algorithm that provides a simple and concise approach to the diagnosis of a renal mass. It differs in design from that previously suggested by us and others because of decreased emphasis on nuclear medicine and greater emphasis on computed tomography. The more pivotal position assumed by computed tomography is based on improved scanner design and several large series attesting to the accuracy and cost-effectiveness of this imaging technique. It behooves internists to appreciate the role of various imaging tools in evaluating a renal mass. With radiologic consultation, internists should strive to confidently establish the cystic nature of a renal mass and to refer to a urologist solid masses or those whose nature remains persistently equivocal.

Fine needle aspiration cytology in the diagnosis of solid renal and adrenal masses

In the eight-year period 1977-1984, 83 renal and adrenal mass lesions which were not clearly simple cysts by ultrasonographic examination (US) were investigated by percutaneous fine needle aspiration (FNA) biopsy. Initially, biopsy was often guided by fluoroscopy, later US was by far the most commonly used modality. There were 77 renal and 6 adrenal masses; 69 lesions were malignant and 14 were benign. A positive cytological diagnosis of malignancy was given in 62 cases, a diagnostic sensitivity of 90%. One false positive diagnosis occurred, an angiomyolipoma was misinterpreted as a low grade renal cell tumour. One significant complication was recorded, post biopsy haemorrhage into a large, extensively necrotic renal adenocarcinoma causing severe pain. The place of FNA in the preoperative investigation of solid renal tumours is discussed on the basis of this experience and results reported in the literature.

Imaging of urinary tract disease. Current approaches

Current modalities and techniques used in imaging of the urinary tract offer prompt and accurate diagnoses as well as treatment in some cases. Careful planning and judgement in the choice of the imaging sequence is important in avoiding redundant or ill-advised tests. Individual tailoring will be necessary in some patients. It is hoped that with the rational use of the diagnostic tools now available and with the continued improvement in MRI technology, safe and accurate diagnoses will be expected in practically all patients with diseases of the urinary tract.

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.

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.

Computerized tomography scan for diagnosis and staging of renal cell carcinoma

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.