E. M. Sager

Contrast-enhanced computed tomography to show perivesical extension in bladder carcinoma

Fifty-two patients (53 lesions) with muscle invasive carcinoma (T2/T3) of the urinary bladder were examined with computed tomography (CT) before planned total cystectomy. The object of CT was to demonstrate perivesical growth. All patients were examined before and after intravenous injection of contrast medium. The stages obtained from the precontrast and postcontrast scans were compared with the histopathologic stage from the cystectomy specimen. CT staged correctly 35 of the 53 lesions in the precontrast series and 46 of the 53 lesions in the postcontrast series. The improved accuracy from contrast enhancement resulted primarily from fewer cases being overstaged. The use of intravenous contrast medium improved accuracy of CT in evaluation of perivescial tumor growth.

Contrast-enhanced computed tomography in carcinoma of the urinary bladder: The Use of Different Injection Methods

Computed tomography (CT) scans of the urinary bladder were taken before and in combination with intravenous contrast medium injection in 30 patients with invasive bladder carcinoma. Three different ways of injecting the same amount of intravenous contrast material were used in three groups, each consisting of ten patients. In the first group the contrast medium was given during 90 seconds, in the second group during 40 seconds and in the third one, the first half during 20 seconds and the second half during 90 seconds. The attenuation in the tumors and in the bladder wall was measured in Hounsfield units. Independent of injection method, all tumors showed significantly higher contrast enhancement than the bladder wall when the injection was terminated. The difference in contrast enhancement was greatest in the group where the shortest injection time was used and greatest immediately after the conclusion of the injection. The difference in contrast enhancement between tumor and bladder wall was visible on the monitor in all cases.

Cisplatin and Medium Dose Methotrexate in Advanced Transitional Cell Carcinoma of the Urinary Tract

Twenty-seven patients with advanced transitional cell carcinoma of the urothelium were studied. The area of each tumour was measured by computed tomography. Twenty-four of the 27 patients were evaluated after treatment with the following course of chemotherapy given intravenously: day 1-cisplatin 50 mg/m2; day 2-methotrexate 250 mg/m2; and folinic acid rescue treatment 24 hours after the methotrexate infusion. Each cycle of treatment was given three times, with two weeks between cycles. There were two complete and 11 partial responses, and the primary tumour responded as often as the distant metastases. The toxicity of the regimen was acceptable, even given the advanced age of most of the patients. Most of whom found that their disturbances of micturition and sleeping problems were improved by the treatment. Cisplatin combined with methotrexate achieves a response rate of about 50% in advanced transitional cell carcinoma. When combinations of chemotherapy are being chosen for these often elderly patients the curability and palliation effects must be balanced against the toxicity and morbidity.

Computed tomography of the urinary bladder shortly after radiation therapy for rectal carcinoma

Eighteen patients with rectal carcinoma were examined with computed tomography (CT), before and shortly after preoperative irradiation. Changes in the bladder that could be mistaken for tumor growth did not occur at CT. However, considerable individual variations were seen. Radiation therapy did not result in increased contrast enhancement of the bladder wall after irradiation. The bladder wall thickness increased somewhat during and after treatment and the bladder volume was reduced. Localized thickening with little contrast enhancement was seen in the anterior bladder wall in 3 patients. One case of irradiation cystitis was noted. Edema was seen in the perivesical fat, but could in no case be mistaken for tumor growth.

Computed tomography of invasive bladder carcinoma after diagnostic transurethral resection

Fourteen patients with known muscle invasive bladder carcinoma were examined with computed tomography (CT) before and five to seven days after diagnostic transurethral resection (TUR). The CT examinations included pre- and postcontrast series. In order to standardize the technique, we examined on a distended bladder. No significant changes occurred for the whole group after TUR. Individual changes were seen. In six patients the largest measured area of the bladder tumor increased after resection and in four the largest measured thickness increased, and this should be borne in mind when CT is used to evaluate tumor response to treatment. Perivesical changes occurred only after extensive diathermy or perforation. They did not show contrast enhancement and could therefore not be mistaken for tumor growth.

Features of Irradiated Urinary Bladder Tumors and Their Correlation with Malignancy Observed on Computed Tomography

CT features of 42 masses in the bladder wall were characterized and subjected to analysis to find indicators of malignancy. A CT technique with thin slices and intravenous contrast medium was used. Multiple regression and multivariate analysis showed good ability of contrast-enhanced CT to discriminate between benign and malignant masses in the bladder wall. Protrusion of a mass into the perivesical fat had some importance in discriminating between malignant tumors with and without perivesical growth although the detection of perivesical growth was less certain.

Absorbed Dose Resulting from a Specially Designed Computed Tomography Technique for Examination of the Urinary Bladder

The absorbed spatial dose distribution resulting from a specially designed CT protocol for examination of the urinary bladder has been investigated with TLD rods in a body phantom containing tissue equivalent material. The CT examination consisted of scout view and both pre- and postcontrast scan series with 5 mm slice thickness and 5 mm unscanned intervals between successive scans. Cross-sectional dose distribution for one scan in the plane of the ovaries was measured as well as the dose profile for one scan along a line through the ovary parallel to the axis of rotation. Based on these measurements, the dose resulting from the whole CT examination was calculated, both with contiguous and noncontiguous scans. The ovarian dose was calculated for different positions of the ovaries in relation to the scanned area. The absorbed dose varied between 8.3 mGy and 9.7 mGy with the actual technique used. When contiguous scans with the same thickness were taken, the ovarian dose increased with a factor from 1.7 to 1.9. The dose resulting from the CT protocol of the urinary bladder was of the same magnitude as absorbed dose resulting from urography. When the diagnostic gain from a precise definition of tumor extent was taken into account, the dose resulting from the CT protocol was judged acceptable.