Colorectal and extracolonic cancers detected at screening CT colonography in 10,286 asymptomatic adults.

PURPOSE: To retrospectively determine the detection rates, clinical stages, and short-term patient survival for all unsuspected cancers identified at screening computed tomographic (CT) colonography, including both colorectal carcinoma (CRC) and extracolonic malignancies. MATERIALS AND METHODS: From April 2004 through March 2008, prospective colorectal and extracolonic interpretation was performed in 10,286 outpatient adults (5388 men, 4898 women; mean age, 59.8 years) undergoing screening CT colonography at two centers in this institutional review board-approved, HIPAA-compliant study. For all histologically proved, clinically unsuspected cancers detected at CT colonography that were identified at retrospective review of the medical records, the stage of disease, treatment, and clinical outcome were analyzed. Benign neoplasms (including advanced colorectal adenomas), symptomatic lesions, and tumors without pathologic proof were excluded. Statistical analysis was performed with Fisher exact test and two-sample z test. RESULTS: Unsuspected cancer was confirmed in 58 (0.56%) patients (33 women, 25 men; mean age, 60.8 years), which included invasive CRC in 22 patients (0.21%) and extracolonic cancer in 36 patients (0.35%). Extracolonic malignancies included renal cell carcinoma (n = 11), lung cancer (n = 8), non-Hodgkin lymphoma (n = 6), and a variety of other tumors (n = 11). Cancers in 31 patients (53.4%) were stage I or localized. At the most recent clinical follow-up (mean, 30.0 months +/- 11.8 [standard deviation]; range, 12-56 months), three patients (5.2%) had died of their cancer. CONCLUSION: The overall detection rate of unsuspected cancer is approximately one per 200 asymptomatic adults undergoing routine screening CT colonography, including about one invasive CRC per 500 cases and one extracolonic cancer per 300 cases. Detection and treatment at an early presymptomatic stage may have contributed to the favorable outcome.

Stone measurement by volumetric three-dimensional computed tomography for predicting the outcome after extracorporeal shock wave lithotripsy.

OBJECTIVE: To evaluate the efficacy of stone volume measured using a three-dimensional (3D) reconstruction of preoperative non-contrast computed tomography (NCCT) as an independent predictor of success after extracorporeal shock wave lithotripsy (ESWL) of upper urinary tract calculi. PATIENTS AND METHODS: We evaluated preoperative NCCT in 94 patients who had ESWL for solitary upper urinary tract calculi of 4-20 mm in diameter. Axial images were used to measure the skin-to-stone distance (SSD), Hounsfield Unit (HU) density and axial stone diameter. Stone volume was calculated on a volume-rendered 3D image for each stone. Maximum stone length was determined by comparative measurements of each stone in coronal, sagittal and axial planes, and was also measured on a plain abdominal film before ESWL. For ESWL we used the DoliS lithotripter (Dornier Medical Systems, Marrietta, GA, USA). A plain film at 6 weeks was used to categorize patients as stone-free (SF) or with residual stone. RESULTS: In all, 58 (62%) patients were SF and 36 (38%) had RS; the mean stone volume was significantly different between these groups (274 vs 464 microL, P = 0.002). Logistic regression analysis showed that stone volume was the strongest predictor of SF status (P < 0.001), compared to peak HU (P = 0.015), mean HU (P = 0.04) and axial stone diameter (P = 0.006). The body mass index, SSD and maximum stone length on NCCT or a plain film did not predict success. A stone volume of <500 microL best predicted treatment success (P < 0.001) with 72% of patients with a stone volume of <500 microL having a successful outcome, vs only 27% with a stone volume of >500 microL. CONCLUSION: Our study suggests that stone volume is an optimal predictor of SF status after ESWL of solitary upper urinary tract calculi.

Primary 2D versus primary 3D polyp detection at screening CT colonography.

OBJECTIVE: Disparate results from the existing large CT colonography (CTC) trials suggest that 2D polyp detection is less sensitive than 3D detection, but no direct evidence exists to support this claim. Our goal was to assess the sensitivity of primary 2D polyp detection with cases from the Department of Defense CTC screening trial and compare results with the primary 3D evaluation and previous 2D CTC trials. MATERIALS AND METHODS: Ten radiologists, blinded to polyp findings, retrospectively interpreted 730 consecutive colonoscopy-proven CTC cases in asymptomatic adults using a primary 2D approach, with 3D reserved for problem solving. Primary 2D CTC performance was compared with the primary 3D CTC results from the original trial of 1,233 asymptomatic adults. The 10 2D reviewers were significantly more experienced in CTC interpretation (> 100 cases interpreted) than the six reviewers from the original 3D trial. RESULTS: Primary 2D CTC sensitivity for adenomas > or = 6 mm was 44.1% (56/127), compared with 85.7% (180/210) at 3D (p < 0.001). Sensitivity of 2D CTC for adenomas > or = 10 mm was 75.0% (27/36) compared with 92.2% (47/51) at 3D (p = 0.027). Similar sensitivity trends were seen for the by-patient analysis and for all polyps at the 6-mm and 10-mm thresholds. By-patient specificity for 2D evaluation at the 10-mm threshold was 98.1% (676/689), compared with 97.4% (1,131/1,161) at 3D evaluation (p = 0.336). CONCLUSION: Primary 2D CTC is less sensitive than primary 3D CTC for polyp detection in low-prevalence screening cohorts. The disappointing 2D sensitivity in this study was very similar to results obtained with primary 2D evaluation in previous CTC trials.