Bladder cancer diagnosis with CT urography: test characteristics and reasons for false-positive and false-negative results

PURPOSE

To determine test characteristics of CT urography for detecting bladder cancer in patients with hematuria and those undergoing surveillance, and to analyze reasons for false-positive and false-negative results.

METHODS

A HIPAA-compliant, IRB-approved retrospective review of reports from 1623 CT urograms between 10/2010 and 12/31/2013 was performed. 710 examinations for hematuria or bladder cancer history were compared to cystoscopy performed within 6 months. Reference standard was surgical pathology or 1-year minimum clinical follow-up. False-positive and false-negative examinations were reviewed to determine reasons for errors.

RESULTS

Ninety-five bladder cancers were detected. CT urography accuracy: was 91.5% (650/710), sensitivity 86.3% (82/95), specificity 92.4% (568/615), positive predictive value 63.6% (82/129), and negative predictive value was 97.8% (568/581). Of 43 false positives, the majority of interpretation errors were due to benign prostatic hyperplasia (n = 12), trabeculated bladder (n = 9), and treatment changes (n = 8). Other causes include blood clots, mistaken normal anatomy, infectious/inflammatory changes, or had no cystoscopic correlate. Of 13 false negatives, 11 were due to technique, one to a large urinary residual, one to artifact. There were no errors in perception.

CONCLUSION

CT urography is an accurate test for diagnosing bladder cancer; however, in protocols relying predominantly on excretory phase images, overall sensitivity remains insufficient to obviate cystoscopy. Awareness of bladder cancer mimics may reduce false-positive results. Improvements in CTU technique may reduce false-negative results.

Immune-related tumour response assessment criteria: a comprehensive review

Growing emphasis on precision medicine in oncology has led to increasing use of targeted therapies that encompass a spectrum of drug classes including angiogenesis inhibitors, immune modulators, signal transduction inhibitors, DNA damage modulators, hormonal agents etc. Immune therapeutic drugs constitute a unique group among the novel therapeutic agents that are transforming cancer treatment, and their use is rising. The imaging manifestations in patients on immune therapies appear to be distinct from those typically seen with conventional cytotoxic therapies. Patients on immune therapies may demonstrate a delayed response, transient tumour enlargement followed by shrinkage, stable size, or initial appearance of new lesions followed by stability or response. These newer patterns of response to treatment have rendered conventional criteria such as World Health Organization and response evaluation criteria in solid tumours suboptimal in monitoring changes in tumour burden. As a consequence, newer imaging response criteria such as immune-related response evaluation criteria in solid tumours and immune-related response criteria are being implemented in many trials to effectively monitor patients on immune therapies. In this review, we discuss the traditional and new imaging response criteria for evaluation of solid tumours, review the outcomes of various articles which compared traditional criteria with the new immune-related criteria and discuss pseudo-progression and immune-related adverse events.

Imaging appearance of topical haemostatic agents: pictorial review

Topical haemostatic agents have become an essential tool to assist with the control of bleeding during surgery as well as to facilitate wound closure. The imaging appearance of these agents can overlap that of abscess or tumour. Knowledge of the appearance of these various agents on ultrasound and CT is crucial to avoid misdiagnosing pathology, potentially resulting in unnecessary interventional procedures.

CT restaging of testicular germ cell tumors: The incidence of isolated pelvic metastases

PURPOSE

We determined the incidence of isolated pelvic metastases at restaging computed tomography (CT) in patients with testicular germ cell tumors to consider if imaging the pelvis could be omitted.

METHODS

After receiving IRB approval for this HIPAA-compliant retrospective study, medical records of 560 men (mean age 32.8) with 583 testicular germ cell tumors who underwent 3683 restaging CT scans of the abdomen and pelvis were reviewed to determine the proportion of patients with metastatic disease in the pelvis alone, as verified by histology or by resolution after therapy. Chi-square statistical analysis tested the association between factors currently thought to predispose patients to pelvic metastases. Patients were also categorized by clinical stage, tumor histology, and initial treatment.

RESULTS

Isolated pelvic metastases were detected in nine (1.6%) of 560 men. Neither bulky abdominal disease (p=0.85) nor extratesticular invasion by the primary tumor (p=0.37) were statistically significant in predicting which patients were more likely to have isolated pelvic metastases. Among the nine patients with isolated pelvic recurrence, only three (0.7%) of 408 men with no known pelvic disease at initial staging and no tumor marker elevation at restaging had isolated pelvic metastases. Isolated pelvic recurrence was not statistically different when analyzed by initial stage and treatment.

CONCLUSION

The incidence of isolated pelvic metastases in testicular germ cell tumors at restaging CT is low, but no group of patients was found to be without risk. Therefore, given the small, if any, risk of radiation-induced harm, the decision about whether to include routine pelvic CT in surveillance protocols should be individualized.

Radiogenomics of clear cell renal cell carcinoma: preliminary findings of The Cancer Genome Atlas-Renal Cell Carcinoma (TCGA-RCC) Imaging Research Group

PURPOSE

To investigate associations between imaging features and mutational status of clear cell renal cell carcinoma (ccRCC).

MATERIALS AND METHODS

This multi-institutional, multi-reader study included 103 patients (77 men; median age 59 years, range 34-79) with ccRCC examined with CT in 81 patients, MRI in 19, and both CT and MRI in three; images were downloaded from The Cancer Imaging Archive, an NCI-funded project for genome-mapping and analyses. Imaging features [size (mm), margin (well-defined or ill-defined), composition (solid or cystic), necrosis (for solid tumors: 0%, 1%-33%, 34%-66% or >66%), growth pattern (endophytic, <50% exophytic, or ≥50% exophytic), and calcification (present, absent, or indeterminate)] were reviewed independently by three readers blinded to mutational data. The association of imaging features with mutational status (VHL, BAP1, PBRM1, SETD2, KDM5C, and MUC4) was assessed.

RESULTS

Median tumor size was 49 mm (range 14-162 mm), 73 (71%) tumors had well-defined margins, 98 (95%) tumors were solid, 95 (92%) showed presence of necrosis, 46 (45%) had ≥50% exophytic component, and 18 (19.8%) had calcification. VHL (n = 52) and PBRM1 (n = 24) were the most common mutations. BAP1 mutation was associated with ill-defined margin and presence of calcification (p = 0.02 and 0.002, respectively, Pearson's χ (2) test); MUC4 mutation was associated with an exophytic growth pattern (p = 0.002, Mann-Whitney U test).

CONCLUSIONS

BAP1 mutation was associated with ill-defined tumor margins and presence of calcification; MUC4 mutation was associated with exophytic growth. Given the known prognostic implications of BAP1 and MUC4 mutations, these results support using radiogenomics to aid in prognostication and management.

PET/CT-guided percutaneous liver mass biopsies and ablations: targeting accuracy of a single 20 s breath-hold PET acquisition

AIM

To determine whether a single 20 s breath-hold positron-emission tomography (PET) acquisition obtained during combined PET/computed tomography (CT)-guided percutaneous liver biopsy or ablation procedures has the potential to target 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG)-avid liver masses as accurately as up to 180 s breath-hold PET acquisitions.

MATERIALS AND METHODS

This retrospective study included 10 adult patients with 13 liver masses who underwent FDG PET/CT-guided percutaneous biopsies (n = 5) or ablations (n = 5). PET was acquired as nine sequential 20 s, monitored, same-level breath-hold frames and CT was acquired in one monitored breath-hold. Twenty, 40, 60, and 180 s PET datasets were reconstructed. Two blinded readers marked tumour centres on randomized PET and CT datasets. Three-dimensional spatial localization differences between PET datasets and either 180 s PET or CT were analysed using multiple regression analyses. Statistical tests were two-sided and p < 0.05 was considered significant.

RESULTS

Targeting differences between 20 s PET and 180 s PET ranged from 0.7-20.3 mm (mean 5.3 ± 4.4 mm; median 4.3) and were not statistically different from 40 or 60 s PET (p = 0.74 and 0.91, respectively). Targeting differences between 20 s PET and CT ranged from 1.4-36 mm (mean 9.6 ± 7.1 mm; median 8.2 mm) and were not statistically different from 40, 60, or 180 s PET (p = 0.84, 0.77, and 0.35, respectively).

CONCLUSION

Single 20 s breath-hold PET acquisitions from PET/CT-guided percutaneous liver procedures have the potential to target FDG-avid liver masses with equivalent accuracy to 180 s summed, breath-hold PET acquisitions and may facilitate strategies that improve image registration and shorten procedure times.

A prospective feasibility study of radiation and concurrent bevacizumab for recurrent endometrial cancer

OBJECTIVES

To determine the toxicity and survival rates in a trial of concurrent bevacizumab and external beam radiation (EB) for patients with recurrent endometrial or ovarian cancer.

METHODS

Nineteen women with recurrent endometrial (n = 15) or ovarian (n = 4) cancer with gross disease involving the vaginal cuff, and/or pelvic nodes and/or para-aortic nodes, cancer were enrolled between 2008 and 2010. All patients received bevacizumab during radiation. Toxicity was assessed at baseline, weekly during treatment and every 3 months for at least 1 year after treatment.

RESULTS

All patients completed EB on schedule. For the 15 patients with recurrent endometrial cancer, the 1- and 3-year progression-free survival (PFS was) 80%/67% and overall survival (OS) was 93%/80%. Patients that had a vaginal cuff recurrence alone had a 1- and 3-year PFS of 75%/63% and OS of 100%/75%. Two patients with pelvic node involvement did not recur throughout the entire follow-up period. The 5 patients with para-aortic node involvement had a 1- and 3-year PFS of 80%/60% and OS of 80%/80%. Of the 4 ovarian cancer patients 3 relapsed with 1- and 3-year PFS of 80%/40% and OS of 100%/60%. Toxicities included thrombosis and 1 embolic event in the setting of metastatic disease. No gastrointestinal perforations were noted.

CONCLUSIONS

Delivering bevacizumab with concurrent radiation provides excellent local tumor control and survival for women with recurrent endometrioid endometrial cancer, particularly those with unresectable nodes. Caution must be used in those at highest risk of developing metastatic disease given the increased risk of thromboembolic events. This regimen may be considered for recurrent gynecologic malignancies in future trials.

Body CT scanning in young adults: examination indications, patient outcomes, and risk of radiation-induced cancer

PURPOSE

To quantify patient outcome and predicted cancer risk from body computed tomography (CT) in young adults and identify common indications for the imaging examination.

MATERIALS AND METHODS

This retrospective multicenter study was HIPAA compliant and approved by the institutional review boards of three institutions, with waiver of informed consent. The Research Patient Data Registry containing patient medical and billing records of three university-affiliated hospitals in a single metropolitan area was queried for patients 18-35 years old with a social security record who underwent chest or abdominopelvic CT from 2003 to 2007. Patients were analyzed according to body part imaged and scanning frequency. Mortality status and follow-up interval were recorded. The Biologic Effects of Ionizing Radiation VII method was used to calculate expected cancer incidence and death. Examination indication was determined with associated ICD-9 diagnostic code; 95% confidence intervals for percentages were calculated, and the binomial test was used to compare the difference between percentages.

RESULTS

In 21 945 patients, 16 851 chest and 24 112 abdominopelvic CT scans were obtained. During the average 5.5-year (± 0.1 [standard deviation]) follow-up, 7.1% (575 of 8057) of chest CT patients and 3.9% (546 of 13 888) of abdominal CT patients had died. In comparison, the predicted risk of dying from CT-induced cancer was 0.1% (five of 8057, P < .01) and 0.1% (eight of 12 472, P < .01), respectively. The most common examination indications were cancer and trauma for chest CT and abdominal pain, trauma, and cancer for abdominopelvic CT. Among patients without a cancer diagnosis in whom only one or two scans were obtained, mortality and predicted risk of radiation-induced cancer death were 3.6% (215 of 5914) and 0.05% (three of 5914, P < .01) for chest CT and 1.9% (219 of 11 291) and 0.1% (six of 11 291, P < .01) for abdominopelvic CT.

CONCLUSION

Among young adults undergoing body CT, risk of death from underlying morbidity is more than an order of magnitude greater than death from long-term radiation-induced cancer.

Sonographic and magnetic resonance imaging findings in uterine incarceration

We show the sonographic and magnetic resonance imaging features of uterine incarceration. Clinical data and imaging findings were retrospectively reviewed for 8 confirmed cases identified by sonography from 2000 to 2010. Two patients had magnetic resonance imaging. Seven of 8 patients (87.5%) presented with abdominal pain; 4 of 8 (50.0%) also had urinary symptoms. All had a retroverted uterus with an elongated anterosuperiorly displaced or poorly visualized cervix on sonography. Magnetic resonance imaging showed similar features, but in both cases, the placental position was misinterpreted because of severe uterine retroversion. Radiologists should be aware of this condition and its imaging features to reduce associated morbidity and mortality.

Mucinous tubular and spindle cell carcinoma of the kidney: imaging features

This article describes the features on sonography, computed tomography (CT) and magnetic resonance imaging (MRI) of mucinous tubular and spindle cell carcinoma of the kidney. Six pathologically proven cases of mucinous tubular and spindle cell carcinoma of the kidney were identified (5 females, 1 male); all patients underwent preoperative imaging. The mean age of the patients was 58.5 years. Thirteen imaging studies were available for review: 2 sonograms, 1 unenhanced CT scan, 5 contrast-enhanced CT scans, 1 unenhanced magnetic resonance imaging (MRI) examination, and 4 contrast-enhanced MRI examinations. Two abdominal radiologists evaluated all images retrospectively on a PACS workstation using a standardized data collection sheet until consensus was reached. All mucinous tubular and spindle cell carcinomas presented as well-marginated, small (mean 2.6 cm, range 1.9-3.2 cm) predominantly solid masses. No intratumoral fat or calcification was identified. Unenhanced CT and MRI appearances were variable as was the degree of enhancement following intravenous contrast material administration. There was no evidence of perinephric extension, renal vein involvement or metastatic disease in any of the cases. The radiological appearance of mucinous tubular and spindle cell carcinoma is diverse and therefore indistinguishable from the more common subtypes of renal cell carcinoma.

Frequent body CT scanning of young adults: indications, outcomes, and risk for radiation-induced cancer

PURPOSE

The aims of this study were to define the magnitude of frequent body CT scanning of young adults and to determine associated patient diagnoses, examination indications, short-term outcomes, and estimated radiation-induced cancer risk.

METHODS

Patients aged 18 to 35 years who underwent chest or abdominopelvic CT between 2003 and 2007 at any of 3 hospitals were identified and categorized by total number of scans per body part as rarely (<5), intermediately (>5 and <15), or frequently (>15) scanned. Medical records of the frequently scanned were reviewed. Cumulative radiation exposure, calculated from typical effective doses, was used to estimate cancer risk. Cancer incidence and mortality were estimated using the Biological Effects of Ionizing Radiation method.

RESULTS

A total of 25,104 patients underwent 45,632 scans, of whom 23,851 (95%) and 70 (0.3%) were rarely and frequently scanned, respectively. Among frequently scanned patients, the most common diagnoses were cancer (19 of 36 [52.8%]) and cystic fibrosis with lung transplantation (11 of 36 [30.5%]) for chest CT and cancer (25 of 34 [73.5%]) for abdominopelvic CT. During the mean 5.4 years (range, 0.9-7.6 years) of follow-up, 46% of frequently scanned patients (32 of 70) died. Of the 47 cancers predicted in the entire cohort, 36 (77%) and 2 (3%) were expected in the rarely and frequently scanned.

CONCLUSIONS

The majority of CT-induced cancers are predicted to result from sporadic rather than frequent scanning. Frequent scanning confers a significant cancer risk but occurs in severely ill patients, a large proportion of who die before any radiation-induced cancer would be a factor in their health.

Urinary bladder: normal appearance and mimics of malignancy at CT urography

The objective of this review article is to learn how to recognize anatomic variants and benign entities that mimic bladder cancer at computed tomography (CT) urography. Building on recent data that suggest that CT urography can be used to diagnose bladder cancer, recognition of anatomic variants and benign entities will help improve radiologists’ ability to diagnose bladder cancer.

Hepatic arterial chemoembolization using drug-eluting beads in gastrointestinal neuroendocrine tumor metastatic to the liver

PURPOSE

This study was designed to evaluate short (<3 months) and intermediate-term (>3 months) follow-up in patients with metastatic neuroendocrine tumor to the liver who underwent hepatic arterial chemoembolization with drug-eluting beads at a single institution.

METHODS

Institutional review board approval was obtained for this retrospective review. All patients who were treated with 100-300 or 300-500 μm drug-eluting LC Beads (Biocompatibles, UK) preloaded with doxorubicin (range, 50-100 mg) for GI neuroendocrine tumor metastatic to the liver from June 2004 to June 2009 were included. CT and MRI were evaluated for progression using Response Evaluation Criteria In Solid Tumors (RECIST) or European Association for the Study of the Liver (EASL) criteria. Short-term (<3 months) and intermediate-term (>3 months) imaging response was determined and Kaplan-Meier survival curves were plotted.

RESULTS

Thirty-eight drug-eluting bead chemoembolization procedures were performed on 32 hepatic lobes, comprising 21 treatment cycles in 18 patients. All procedures were technically successful with two major complications (biliary injuries). At short-term follow-up (<3 months), 22 of 38 (58%) procedures and 10 of 21 (48%) treatment cycles produced an objective response (OR) with the remainder having stable disease (SD). At intermediate-term follow-up (mean, 445 days; range, 163-1247), 17 of 26 (65%) procedures and 8 of 14 (57%) treatment cycles produced an OR. Probability of progressing was approximately 52% at 1 year with a median time to progression of 419 days.

CONCLUSIONS

Drug-eluting bead chemoembolization is a reasonable alternative to hepatic arterial embolization and chemoembolization for the treatment of metastatic neuroendocrine tumor to the liver.

Bladder cancer detection with CT urography in an Academic Medical Center

PURPOSE

To evaluate the performance characteristics of computed tomographic (CT) urography for the detection of bladder cancer in patients at risk for the disease.

MATERIALS AND METHODS

Institutional review board approval was obtained for this retrospective HIPAA-compliant review of medical records of 2600 consecutive patients undergoing CT urography. Of these, 838 CT urograms in 779 patients (449 men, mean age of 62 years, range of 27-92 years; 330 women, mean age of 56 years, range of 18-86 years) evaluated for hematuria or a history of urothelial cancer, who had undergone cystoscopy within 6 months of the CT urogram, were included in the study. Clinical reports of CT urograms containing a bladder lesion interpreted as suspicious for malignancy were classified as positive. All others were classified as negative. Cystoscopy reports were classified as positive if a lesion underwent biopsy or was resected or negative if no lesion was detected. Performance characteristics for both CT urography and cystoscopy were determined by using pathologic findings or clinical follow-up as the reference standard. Ninety-five percent confidence intervals were estimated for each test characteristic.

RESULTS

The overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value (NPV) for bladder cancer detection were 79% (117 of 149), 94% (649 of 689), 91% (766 of 838), 75% (117 of 157), and 95% (649 of 681) for CT urography and 95% (142 of 149), 92% (634 of 689), 93% (776 of 838), 72% (142 of 197), and 99% (634 of 641) for cystoscopy. The NPV of CT urography was higher in patients evaluated for hematuria alone (98%, 589 of 603). However, the accuracy of CT urography was considerably lower in patients with a prior urothelial malignancy (78%, 123 of 158).

CONCLUSION

CT urography is an accurate noninvasive test for detecting bladder cancer in patients at risk for the disease. The high NPV of CT urography in patients with hematuria may obviate cystoscopy in selected patients.