Shaun A. Nguyen

Iso-Osmolality versus Low-Osmolality Iodinated Contrast Medium at Intravenous Contrast-enhanced CT: Effect on Kidney Function

PURPOSE To determine the effects of iso-osmolality contrast medium compared with a low-osmolality agent on renal function (serum creatinine [SCr] and glomerular filtration rate [GFR]) in high-risk patients undergoing intravenous contrast material-enhanced CT. MATERIALS AND METHODS This HIPAA-compliant study was IRB-approved; formal consent was obtained. One hundred seventeen patients (83 men, 34 women; mean age, 64.3 years; range, 18-86 years) with decreased renal function underwent contrast-enhanced CT with either iso-osmolality iodixanol (n = 61) or low-osmolality iopromide (n = 56). Outcome measures were of SCr increase or GFR decrease for 3 days after CT, a SCr increase (of >or=0.5 mg/dL [44.2 micromol/L, 25%] or >or=1.0 mg/dL [88.4 micromol/L, 50%]), a GFR reduction (of >or=5 mL/min), and patient outcome at 30- and 90-day follow-up. RESULTS Iodixanol decreased SCr (mean +/- standard deviation) from 1.77 mg/dL +/- 0.24 (156.47 micromol/L +/- 21.22) at baseline to 1.65 mg/dL +/- 0.35 (145.86 micromol/L +/- 30.94, P = .046) at day 1, 1.73 mg/dL +/- 0.53 (152.93 micromol/L +/- 46.85, not significant) at day 2, and 1.73 mg/dL +/- 0.55 (152.93 micromol/L +/- 48.62, not significant) at day 3 (not significant). Iopromide increased SCr from 1.75 mg/dL +/- 0.32 (154.7 micromol/L +/- 28.29) at baseline to 1.8 mg/dL +/- 0.42 (159.12 micromol/L +/- 15.59) at day 1, 1.77 mg/dL +/- 0.49 (156.47 micromol/L +/- 43.32) at day 2, and 1.77 mg/dL +/- 0.62 (156.47 micromol/L +/- 54.81) at day 3 (not significant). Iodixanol increased and iopromide decreased GFR on all 3 days after CT (not significant). Fewer patients in the iodixanol group (8.5%) than in the iopromide group (27.8%) had SCr increase 0.5 mg/dL or higher (>or=25%, P = .012). Two patients in each group had SCr increase of 1.0 mg/dL or more (not significant). More patients in the iopromide group (42.3%) than in the iodoxanol group (24.1%) had a GFR reduction of 5 mL/min or higher (P = .0426). No patient had a contrast material-related adverse event at 30- or 90-day follow-up. CONCLUSION Intravenous contrast material application in high-risk patients is unlikely to be associated with permanent adverse outcomes. SCr levels after contrast material administration are lower in iodixanol than iopromide groups.

Right Heart: Split-Bolus Injection of Diluted Contrast Medium for Visualization at Coronary CT Angiography

PURPOSE To retrospectively compare a split-bolus contrast medium injection protocol with a biphasic and a monophasic protocol in terms of visualization of the right and left heart, contrast medium-related streak artifacts, and level of attenuation in the cardiac chambers and coronary arteries at coronary computed tomographic (CT) angiography. MATERIALS AND METHODS The human research committee approved this HIPAA-compliant study and waived informed consent. Seventy-five patients had undergone 64-section coronary CT angiography: 25 were injected by using a monophasic, contrast-medium-only protocol with a single-syringe injector; 25 were injected by using a biphasic protocol with a dual-syringe injector; and 25 were injected by using a split-bolus protocol with a dual-syringe injector and an initial bolus of contrast medium followed by 50 mL of a 70%:30% saline-to-contrast medium mixture and a 30-mL saline chaser. Two radiologists rated the visualization of right and left heart structures and the degree of streak artifacts. One observer performed attenuation measurements of the cardiac chambers and of the coronary arteries. Data were analyzed with one-way analysis of variance and Duncan post-hoc multiple comparison procedures. RESULTS Data for 27 women and 48 men (mean age, 62 years) were included. Mean contrast medium attenuation in the right heart was significantly (P < .001) higher in the split-bolus group than in the biphasic injection group but was significantly (P < .001) lower than in the monophasic injection group. For the left heart and the coronary arteries, there were no significant differences among the three groups. Artifacts occurred less frequently (P < .001) in the biphasic and split-bolus groups than in the monophasic group. Visualization of right heart structures was rated significantly (P < .05) better in the split-bolus group than in the two other groups, while there was no difference for visualization of left heart structures. CONCLUSION Split-bolus injection provides sufficient attenuation for visualization of the right heart, while streak artifacts from high-attenuation contrast material can generally be avoided and arterial attenuation is maintained.

Pediatric cardiovascular CT angiography: radiation dose reduction using automatic anatomic tube current modulation.

OBJECTIVE The purpose of this study was to assess the effect of weight-based scanning protocols and automatic tube current modulation on the tube current-time product and image quality at pediatric cardiovascular 64-MDCT angiography. MATERIALS AND METHODS Our pediatric cardiovascular 64-MDCT protocols use a weight-based algorithm to determine nominal tube voltage settings with 80, 100, and 120 kV. Automatic tube current modulation was used for each case. The mAs, volume CT dose index (CTDI(vol)), and dose-length product (DLP) values were recorded and the effective dose calculated. On the basis of the selected nominal tube current, the dose values that would have been delivered without tube current modulation were also calculated. Scans were compared with 16-MDCT using 120 kVp and 120 mAs. Two radiologists independently rated image quality on a 5-point scale. Image noise was objectively measured within four different regions of interest. Findings at CT were clinically correlated with results of cardiac sonography, angiography, or surgery. RESULTS Thirty-eight 64-MDCT and 30 16-MDCT scans were evaluated. Mean diagnostic quality for 64-MDCT was rated at 3.6 +/- 0.4 and mean image noise was 8.9 +/- 4.5 H. Results with 16-MDCT were not significantly different: diagnostic quality (3.6 +/- 0.4; p = 0.97) and image noise (9.1 +/- 2.8 H; p = 0.31). Scanning with automatic tube current modulation significantly (p < 0.05) reduced the tube current time-product compared with scanning without automatic tube current modulation (-57.8%/54.1/128 mAs) or with 16-MDCT (-47.9%/54.1/104.37 mAs), respectively. The mAs values were significantly (p < 0.05) lower for 80 kVp than for 100 or 120 kVp scans, but image quality and image noise were not significantly (p = 0.24) different. Agreement between MDCT and clinical findings was excellent. CONCLUSION Under simulated conditions, automatic tube current modulation combined with low tube voltage settings significantly reduced radiation exposure and thus appears preferable in pediatric cardiovascular 64-MDCT.

A trial of drug-induced sleep endoscopy in the surgical management of sleep-disordered breathing†

To determine the reliability and validity of drug‐induced sleep endoscopy (DISE) for patients undergoing surgery for sleep‐disordered breathing (SDB).

Extracapsular dissection for benign parotid tumors: a meta-analysis.

Recent studies suggest that extracapsular dissection (ECD) is an option for the resection of certain benign parotid tumors. This study investigates complication rates and effectiveness of ECD versus superficial parotidectomy (SP) for the treatment of primary benign parotid neoplasms.

Outcome Prediction After Surgery and Chemoradiation of Squamous Cell Carcinoma in the Oral Cavity, Oropharynx, and Hypopharynx: Use of Baseline Perfusion CT Microcirculatory Parameters vs. Tumor Volume

PURPOSE To assess whether pretreatment perfusion computed tomography (PCT) may predict outcome in chemoradiated patients with oral cavity, oropharynx, and hypopharynx squamous cell carcinoma (SCCA) after surgical excision. MATERIALS AND METHODS Twenty-one patients with SCCA were examined before treatment. The primary site was oral cavity in 6, oropharynx in 7, and hypopharynx in 8 patients; there were 11 T2, 6 T3, and 4 T4 tumors. PCT was performed at the level of largest tumor diameter based on standard neck CT. The data were processed to obtain blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface area product (PS). Regions of interest were free-hand positioned on the lesions to obtain PCT measurements. Tumor volume was also calculated. Follow-up was performed with positron emission tomography (PET)/CT and endoscopy. Pearson correlation coefficient was used for comparison between the subgroups. A regression model was constructed to predict recurrence based on the following predictors: age, gender, tumor (T) and nodal (N) stage, tumor volume, and PCT parameters. RESULTS BF(mean), BF(max), BV(mean), BV(max), MTT(mean), PS(mean), and PS(max) were significantly different between patients with and without tumor recurrence (0.0001, p < 0.04). T stage, tumor volume, N stage, BF(max), BV(max), MTT(mean), and radiation dose (p < 0.001) were independent predictors for recurrence. Cox proportional hazards model for tumor recurrence revealed significantly increased risk with high tumor volume (p = 0.00001, relative risk [RR] 7.4), low PS(mean) (p = 0.0001, RR 14.3), and low BF(max) (p = 0.002, RR 5.9). CONCLUSIONS Our data suggest that PCT parameters have a prognostic role in patients with SCCA.

Extra-cardiac findings at cardiac CT: experience with 1,764 patients

To investigate incidental extra-cardiac findings (ECF) at cardiac CT based on indication and impact on patient management. We retrospectively reviewed the reports of 1,764 patients who underwent a cardiac CT study between January 1, 2004 and December 31, 2006, including 463 calcium scorings (CS), 737 coronary CT angiograms (CTA), 341 pulmonary vein stenoses (PVS), and 223 bypass grafts (CABG). ECFs were categorized by type of examination, anatomical location and clinical significance. Comparisons were made between examination types to determine if incidental findings varied by indication. There were 507 ECFs with at least one ECF in 441 patients (25.0%). By examination, there was at least 1 ECF in 79/463 CS studies (17.1%), 196/737 CTAs (26.6%), 80/341 PVSs (23.4%) and 86/223 CABGs (38.6%). In 325 patients (18.4%), the findings were considered clinically important and occurred in 60/463 (12.9%) CSs, 149/737 (20.2%) CTAs, 56/341 (16.4%) PVSs and 60/223 (26.9%) CABGs. Differences between CABG and other indications and CTA vs. CS for incidental and clinically important findings were statistically significant (p < 0.05). Extra-cardiac findings requiring follow-up occur in 18% of patients and are significantly more frequent in coronary artery CTA and coronary artery bypass studies than in calcium scoring studies.

Excessive alcohol consumption and hypertension : Clinical implications of current research

Substantial evidence demonstrates that: 1) heavy alcohol consumption (three or more standard drinks per day) is associated with and predictive of hypertension; 2) reduction in alcohol consumption is associated with a significant dose‐dependent lowering of mean systolic and diastolic blood pressure; and 3) physician advice can reduce heavy drinking in hypertensive patients. These findings suggest that the routine evaluation of alcohol consumption in hypertensive patients is warranted. The Alcohol Use Disorders Identification Test‐C (AUDTT‐C), a brief, three‐question screening test, is useful in this regard. Alcohol biomarkers can also play a role in detecting and monitoring heavy drinking in hypertensive patients whose self‐reports on the AUDTT‐C are suspect. Carbohydrate‐deficient transfer‐rin, a new alcohol biomarker with high specificity, can provide objective data for feedback and counseling. A routine search for excessive use of alcohol, along with brief interventions and monitoring, can have a major impact on reducing the prevalence of hypertension in the general population.

A comparison of outcomes using intensity-modulated radiation therapy and 3-dimensional conformal radiation therapy in treatment of oropharyngeal cancer.

IMPORTANCE Approximately 50% of head and neck cancer survivors experience dysphagia and related morbidity. Intensity-modulated radiation therapy (IMRT) is increasingly used to treat oropharyngeal cancers with excellent oncologic outcomes, but few studies have compared it with conventional 3-dimensional conformal radiation therapy (3D-CRT) to determine whether it can decrease treatment-related toxic and adverse effects. OBJECTIVE To determine whether IMRT improves percutaneous endoscopic gastrostomy (PEG) tube and treatment-related toxicity outcomes compared with 3D-CRT in patients with oropharyngeal squamous cell carcinoma. DESIGN, SETTING, AND PARTICIPANTS Retrospective review of 159 patients with oropharyngeal primary tumors with no history of chemotherapy, radiation therapy, or surgery of the head and neck who underwent definitive treatment with radiotherapy for oropharyngeal squamous cell carcinoma at the Hollings Cancer Center outpatient clinic, Medical University of South Carolina, from 2000 to 2009. INTERVENTION Doses of 70 Gy in 35 daily fractions of radiotherapy delivered via IMRT or 3D-CRT. MAIN OUTCOMES AND MEASURES Primary end points included PEG tube dependence 1 year after radiotherapy start, weight loss during treatment, and change in Eastern Cooperative Oncology Group performance status. Secondary end points included overall and disease-free survival, disease recurrence, and toxic effect profiles. RESULTS The IMRT group (n = 103) had a significantly lower rate of PEG tube dependence 1 year after treatment initiation than the 3D-CRT group (n = 56) for all patients (P = .02) and for those with advanced T stage (P = .01) and a shorter time to PEG tube removal (P < .001). Acute grade 3 or greater toxic effects to skin and mucous membranes occurred less frequently in the IMRT group (P = .02 and P < .001, respectively). The 2 groups did not differ significantly in weight loss, treatment failure (hazard ratio, 0.82 [95% CI, 0.47-1.41]), overall survival (P = .45), or disease-free survival (P = .26). CONCLUSIONS AND RELEVANCE The use of IMRT significantly improves PEG tube and toxicity-related outcomes compared with 3D-CRT in the treatment of oropharyngeal primary cancers. Given the association between mucosal toxic effects, PEG tube dependence, and dysphagia, these findings may be an indication of improved swallowing outcomes with IMRT.

A randomized, double-blind, placebo-controlled clinical study to assess safety and clinical activity of OTO-104 given as a single intratympanic injection in patients with unilateral Ménière's disease.

Objective To evaluate the safety, tolerability, and clinical activity of a single intratympanic injection of OTO-104, sustained-release dexamethasone formulation, in patients with unilateral Ménière’s disease. Study Design Prospective, double-blind, randomized, placebo-controlled, dose-escalation study of 16 weeks’ (4–wk lead-in before dosing; 12–wk follow-up after dosing) duration for each patient. Setting Fifteen centers (physician offices and academic or tertiary referral centers). Patients Forty-four patients aged 22 to 75 years. Intervention Single intratympanic injection of OTO-104 (3 or 12 mg) or placebo. Main Outcome Measures Safety and tolerability were assessed via adverse event reports, otoscopy, audiometry, and tympanometry. Clinical activity was assessed primarily as changes in vertigo frequency. Results OTO-104 was well tolerated, with no impact on hearing function. Plasma levels were observed in a few patients and were barely quantifiable. The most frequently reported adverse event considered related to investigational product was tympanic membrane perforation; no clinical sequelae were associated with these perforations and all were graded mild or moderate. At Month 3, the observed mean ± standard deviation (SD) change from baseline in vertigo frequency was −0.124 ± 0.153, −0.147 ± 0.166, and −0.211 ± 0.153 for the placebo, 3-mg OTO-104, and 12-mg OTO-104 groups, respectively; corresponding to 42%, 56% and 73% reductions in vertigo frequency, respectively. Similar results were observed for tinnitus, measured by the Tinnitus Handicap Inventory (THI–25). Conclusion OTO-104 was safe and well tolerated. Although the sample size was small, the data suggest 12 mg of OTO-104 was associated with a clinically meaningful reduction in vertigo frequency compared to placebo 3 months after treatment.