Imaging in the staging of renal cell carcinoma

Is ultrasound imaging inferior to computed tomography or magnetic resonance imaging in evaluating renal mass size?

OBJECTIVE

To evaluate whether ultrasonography was inferior in detecting the size of a renal mass preoperatively because of the increased attention on the harmful effects of ionizing radiation in medical imaging.

METHODS

A prospectively maintained database was reviewed of all patients who underwent renal ultrasonography before definitive therapy for the renal mass. Every patient who underwent ultrasound imaging also underwent computed tomography (CT) or magnetic resonance imaging (MRI), or both, before treatment. The size of the largest tumor identified per imaging modality was compared among the modalities using correlation and analysis of variance.

RESULTS

A total of 116 patients underwent ultrasound imaging before therapy. Of these patients, 80 also underwent MRI, 66 underwent CT, and 38 underwent all 3 modalities before treatment. The average pathologic tumor size for the entire cohort was 4.45 cm (range 1-13). The size differences between CT and MRI compared with ultrasound were small (<3.5%). Compared with MRI and CT, ultrasound was also well correlated (P<.001 and P<.001). In patients who underwent all 3 imaging modalities, no difference was found in the average tumor size (P=.896).

CONCLUSION

Ultrasound imaging does not appear to be inferior to CT and MRI in the imaging of renal masses. This is useful in reducing the costs and levels of radiation exposure for the long-term follow-up of patients receiving active surveillance.

Neoadjuvant sunitinib for surgically complex advanced renal cell cancer of doubtful resectability: initial experience with downsizing to reconsider cytoreductive surgery

OBJECTIVE

To evaluate neoadjuvant sunitinib in patients with synchronous metastatic renal cell cancer (mRCC) to downsize surgically complex tumours and reconsider cytoreductive surgery.

PATIENTS AND METHODS

Retrospective analysis of ten consecutive mRCC patients treated with sunitinib in an expanded access program who presented with surgically complex primary tumours or bulky locoregional metastases. Surgery-limiting tumour sites (SLTSs) were defined as primary or retroperitoneal lesions with direct invasion of adjacent organs or encasement of vital structures on imaging. Patients received sunitinib 50 mg/day for 4 weeks on and 2 weeks off to be followed by cytoreductive surgery after downsizing and individual reassessment. Response was measured according to Response Evaluation Criteria in Solid Tumours (RECIST).

RESULTS

Six out of ten SLTSs revealed a reduction of tumour size with a median of 14% according to RECIST. None of the ten SLTSs had a partial response (PR), whilst at distant metastatic sites one complete remission and two PRs occurred. Downsizing of SLTSs appeared most prominent in the first 2-4 months, which resulted in reconsidering cytoreductive nephrectomy in three patients. These three tumours invaded the liver on imaging and were reduced by 11, 18 and 20%.

CONCLUSIONS

In this patient group with mRCC and surgically complex primary tumours or locoregional metastases, downsizing of SLTSs by neoadjuvant sunitinib was limited. Cytoreductive surgery was reconsidered in three patients. Given the overall reduction in tumour burden by sunitinib alone, further investigation to define the role of cytoreductive surgery is warranted.

Exploration de l’appareil urinaire en IRM : développements actuels et perspectives futures

New fast MR imaging sequences obtained with high power gradients allow dynamic analysis of parenchymal enhancement by contrast media in order to improve characterization of masses as well as a functional analysis. Phased - array coils have greatly improved spatial resolution. MR Urography is a new valuable modality to study the collecting system. Numerous acronyms are proposed with a wide range of variations between different machines. But basic principles for sequences are similar. MR can be performed in patients with renal insufficiency, iodine allergy or any other contra-indication to the use of ionizing radiation. MRI of the kidney is becoming a major imaging modality to diagnose diseases of the kidney. It provides in a rather short time a "all-in-one approach" of the pathological process.

Retrograde venous invasion causing vertebral metastases in renal cell carcinoma

A case of renal cell carcinoma is presented with renal vein and inferior vena cava tumour/thrombus extension and vertebral metastases centred on the basivertebral veins at three contiguous levels in the low thoracic spine. MRI demonstrated tumour in the intervertebral veins, suggesting that the vertebral deposits were due to retrograde venous spread. To our knowledge, vertebral metastatic deposits due to retrograde venous spread in renal cell carcinoma have not been previously demonstrated directly on imaging. A review is given of the venous anatomy relevant to this mode of spread.

Computerized contrast angiosonography: a new diagnostic tool for the urologist?

OBJECTIVES

To evaluate the diagnostic potential of echo-enhanced ultrasonography (US) for depicting the vascularization pattern of renal cell carcinoma (RCC), and calculating the first-pass effect using harmonic imaging, against that obtained by triphasic helical computed tomography (CT).

PATIENTS AND METHODS

Sixty patients with surgically confirmed RCC underwent US using B-mode and power Doppler methods with or without an intravenous microbubble echo-enhancing agent. After depicting and defining the tumour extent by B-mode US, the first-pass effect/enhancement by the echo-enhancing agent within the lesion, and that of a reference area of unaffected renal cortex, were recorded on-line by calculating the mean pixel intensity. Time-intensity curves, i.e. the rise time and gradient of both the suspected tumour and reference areas, were constructed.

RESULTS

Using B-mode US, the extent of all tumours was delineated (mean tumour size 3.8 cm, SD 0.6). After applying the microbubble agent all tumours were enhanced, whereas the perfusion was decreased (in 48%), increased (in 16%) or similar (in 36%) compared with the cortical reference area. Using the Hounsfield classification, these results correlated well with the hypo/hypervascularity shown on CT.

CONCLUSION

Ultrasonography has considerable potential in diagnosing RCC, if combined with echo-enhancing methods, harmonic imaging and computer-based calculation of tumour vascularization. Dynamic US studies should provide a diagnostic yield similar to that of CT.