Contrast-enhanced C-arm CT evaluation of radiofrequency ablation lesions in the left ventricle

OBJECTIVES

The purpose of this study was to evaluate use of cardiac C-arm computed tomography (CT) in the assessment of the dimensions and temporal characteristics of radiofrequency ablation (RFA) lesions. This imaging modality uses a standard C-arm fluoroscopy system rotating around the patient, providing CT-like images during the RFA procedure.

BACKGROUND

Both cardiac magnetic resonance (CMR) and CT can be used to assess myocardial necrotic tissue. Several studies have reported visualizing cardiac RFA lesions with CMR; however, obtaining CMR images during interventional procedures is not common practice. Direct visualization of RFA lesions using C-arm CT during the procedure may improve outcomes and circumvent complications associated with cardiac ablation procedures.

METHODS

RFA lesions were created on the endocardial surface of the left ventricle of 9 swine using a 7-F RFA catheter. An electrocardiographically gated C-arm CT imaging protocol was used to acquire projection images during iodine contrast injection and after the injection every 5 min for up to 30 min, with no additional contrast. Reconstructed images were analyzed offline. The mean and SD of the signal intensity of the lesion and normal myocardium were measured in all images in each time series. Lesion dimensions and area were measured and compared in pathologic specimens and C-arm CT images.

RESULTS

All ablation lesions (n = 29) were visualized and lesion dimensions, as measured on C-arm CT, correlated well with postmortem tissue measurements (linear dimensions: concordance correlation = 0.87; area: concordance correlation = 0.90. Lesions were visualized as a perfusion defect on first-pass C-arm CT images with a signal intensity of 95 HU lower than that of normal myocardium (95% confidence interval: -111 HU to -79 HU). Images acquired at 1 and 5 min exhibited an enhancing ring surrounding the perfusion defect in 24 lesions (83%).

CONCLUSIONS

RFA lesion size, including transmurality, can be assessed using electrocardiographically gated cardiac C-arm CT in the interventional suite. Visualization of RFA lesions using cardiac C-arm CT may facilitate the assessment of adequate lesion delivery and provide valuable feedback during cardiac ablation procedures.

Current controversies in colorectal surgery: the way to resolve uncertainty and move forward

The are currently a number of unsolved clinical questions in colorectal surgery with new surgical principles being introduced without proper scientific high-level evidence. These include complete mesocolic excision with central ligation for colonic cancer, extralevator abdominoperineal excision for low rectal cancer, robotic surgery for various colorectal procedures, laparoscopic lavage without resection for Hinchey Stage III perforated sigmoid diverticulitis, and the use of the single port technique for laparoscopic surgery. Before general implementation the new modalities should ideally be evalueted in randomized studies and meta-analyses. Many randomized studies, however, cannot give the final answer to the research question because they are underpowered and it is therefore important to perform well-designed studies that are large enough to provide the final answer. A way forward could therefore be to form multicenter and even multinational research groups in order to ensure accrual of sufficient sample sizes.

Effect of postoperative diclofenac on anastomotic healing, skin wounds and subcutaneous collagen accumulation: a randomized, blinded, placebo-controlled, experimental study

BACKGROUND

Retrospective studies have drawn attention to possible detrimental effects of non-steroidal anti-inflammatory drugs (NSAIDs) on the anastomotic leakage rate after colorectal resection. In this study, we examined the effects of the NSAID diclofenac on the breaking strength of an experimental colonic anastomosis and a skin incision as well as subcutaneous collagen accumulation.

METHODS

This was a randomized, blinded, placebo-controlled experimental study in 60 male Wistar rats treated with diclofenac 4 mg/kg/day or placebo. In each rat, a colonic anastomosis was performed and an expanded polytetrafluoroethylene (ePTFE) tube was placed subcutaneously. Incisional and anastomotic wound breaking strength and hydroxyproline content in the ePTFE tubes were measured 7 days after the operation.

RESULTS

We found no significant differences in any of the breaking strength measurements, but showed a median 38% reduction in hydroxyproline deposition as a result of diclofenac treatment (p = 0.03). In the placebo group, subcutaneous collagen deposition tended to correlate positively with skin incisional but negatively with anastomotic bio-mechanical strength.

CONCLUSION

Postoperative diclofenac treatment significantly inhibited collagen deposition in subcutaneous granulation tissue. Anastomotic strength and skin wound strength were not significantly affected. The ePTFE model is suitable for assessing the effect of various drugs on collagen formation and thus on wound healing.

Neuroradiologic correlates of cognitive impairment in adult Moyamoya disease

BACKGROUND AND PURPOSE

MMD has been shown to result in impairment of executive functioning in adults. The purpose of this study was to correlate presurgical neuropsychological assessments with the severity of primary MMD as measured by CBF and CVR and with secondary damage from MMD as estimated by cortical stroke and WMD.

MATERIALS AND METHODS

A retrospective analysis of 31 adult patients with MMD was performed. Xe-CT was used to obtain CBF and CVR, and MRI was reviewed to grade cortical stroke and WMD. Two tests of executive functioning (FAS and TMT-B) were correlated with imaging findings. A multiple regression analysis was performed.

RESULTS

There was a significant overall positive relationship between mean CBF and FAS (P = .038) and TMT-B scores (P = .014). A significant negative relationship was present between the WMD score and the FAS (P = .009) and TMT-B scores (P = .015). Per-region analysis demonstrated that FAS and TMT-B scores were significantly decreased by the presence of a posterior stroke (P < .0001 and P = .001) or WMD (P = .006 and P = .004). All patients with posterior parieto-occipital WMD or stroke also had secondary disease in the anterior regions.

CONCLUSIONS

Impaired executive functioning in adults with MMD is most strongly associated secondary damage in the form of WMD or cortical stroke. The effect is most profound with parieto-occipital lobe involvement, likely a reflection of overall disease severity. Increasing global WMD burden may be a better indicator of cognitive decline than cortical infarction. Patients with higher baseline CBF seem to have better cognitive functioning.

Identification of venous signal on arterial spin labeling improves diagnosis of dural arteriovenous fistulas and small arteriovenous malformations

BACKGROUND AND PURPOSE

DAVFs and small AVMs are difficult to detect on conventional MR imaging/MRA or CTA examinations and often require DSA for definitive diagnosis. The purpose of this study was to assess the value of venous signal intensity on ASL imaging for making this diagnosis.

MATERIALS AND METHODS

Two neuroradiologists and 1 neurologist reviewed MR imaging studies in 26 patients, 15 of whom had DSA-proved DAVFs or small (<2 cm) AVMs. Pseudocontinuous ASL was performed at 1.5T with background-suppressed 3D-FSE readout. Using a 5-point scale, these readers assessed the likelihood of positive findings on a DSA study before and after reviewing the ASL findings. Agreement on imaging findings, including venous ASL signal intensity, was performed by using κ statistics. Logistic regression and ROC analysis were performed to determine which imaging findings improved diagnosis.

RESULTS

Venous ASL signal intensity was seen frequently in cases with positive findings on DSA. The sensitivity and specificity of venous ASL signal intensity for predicting positive findings on a DSA study were 78% and 85%, respectively. On ROC analysis, there was a significant increase in the AUC after review of the ASL images (AUC = 0.798 pre-ASL, AUC = 0.891 post-ASL; P = .02). Multivariate regression identified venous ASL signal intensity as the strongest predictor of positive findings on a DSA study, with an odds ratio of 17.3 (95% CI, 3.3-90.4).

CONCLUSIONS

Identifying venous ASL signal intensity improved detection of DAVFs and small AVMs. Attention to this finding may improve triage to DSA in patients with suspected small vascular malformations.

Percutaneous cholecystostomy for acute cholecystitis: ten-year experience

PURPOSE

To review the clinical course of patients with acute cholecystitis treated by percutaneous cholecystostomy, and to identify risk factors retrospectively that predict outcome.

MATERIALS AND METHODS

A total of 106 patients diagnosed with acute cholecystitis were treated by percutaneous cholecystostomy during a 10-year period. Seventy-one (67%) presented to the emergency department (ED) specifically for acute cholecystitis, and 35 (23%) were inpatients previously admitted for other conditions. Outcomes of the two groups were compared with respect to severity of illness, leukocytosis, bile culture, liver function tests, imaging features, time intervals from onset of symptoms to medical and percutaneous intervention, and whether surgical cholecystectomy was later performed.

RESULTS

Overall, 72 patients (68%) showed an improvement clinically, whereas 34 (32%) showed no improvement or a clinically worsened condition after cholecystostomy. Patients who presented to the ED primarily with acute cholecystitis fared better (84% of patients showed improvement) than inpatients (34% showed improvement; P < .0001). Gallstones were identified in 54% of patients who presented to the ED, whereas acalculous cholecystitis was more commonly diagnosed in inpatients (54%). Patients with sepsis had worse outcomes overall (P < .0001). Bacterial bile cultures were analyzed in 95% of patients and showed positive results in 52%, with no overall effect on outcome. There was no correlation between the time of onset of symptoms until antibiotic therapy or cholecystostomy in either group. Long-term outcomes for both groups were better for those who later underwent cholecystectomy (P < .0001).

CONCLUSIONS

Outcomes after percutaneous cholecystostomy for acute cholecystitis are better when the disease is primary and not precipitated by concurrent illness.

Choosing the best animal species to mimic clinical colon anastomotic leakage in humans: a qualitative systematic review

BACKGROUND/AIMS

Animal models are valuable for studying pathogenic factors and preventive measures for colon anastomotic leakage. The suitability of the species as models varies greatly; however, no consensus exists on which species to use. The aim of this review was to evaluate different experimental animals for the study of clinical colon anastomotic leakage.

METHODS

PubMed and REX database were searched up to October 2010 to identify studies evaluating clinical colon anastomotic leakage in animal models and textbooks on experimental animals, respectively.

RESULTS

Functional models of clinical colon anastomotic leakage have been developed in the mouse, pig, rat, dog and rabbit. However, extreme interventions are needed in order to produce clinical leakage in the rat.

CONCLUSION

Despite the wide use of the rat in this field of research, it seems that its resistance to intra-abdominal infection makes clinical leakage difficult to produce thus rendering the rat unsuited as a model. On the basis of the available literature, we recommend using mice as models mimicking clinical colon anastomotic leakage. Pigs may be an alternative; however, the existing models in this animal are less validated and clinically relevant.

Randomized clinical trial of fibrin sealant versus titanium tacks for mesh fixation in laparoscopic umbilical hernia repair

BACKGROUND

The use of tacks for mesh fixation may induce pain after surgery for ventral hernia. The aim of this study was to compare postoperative pain after laparoscopic ventral hernia repair (LVHR) with conventional mesh fixation using titanium tacks versus fibrin sealant (FS).

METHODS

This randomized clinical trial included patients with an umbilical hernia defect ranging from 1·5 to 5 cm at three Danish hernia centres. Participants were assigned randomly to FS or titanium tack fixation. The primary outcome was acute pain, defined as the mean pain score on days 0-2 after surgery, measured on a 0-100-mm visual analogue scale (VAS).

RESULTS

Forty patients were included, of whom 38 were available for intention-to-treat analysis after 1 month. Patients in the FS group reported less pain than those in the tack group on days 0-2, both at rest (median 19 versus 47 mm; P = 0·025) and during activity (38 versus 60 mm; P = 0·014). The absolute difference in pain score between groups was 19 (95 per cent confidence interval 3 to 34) and 20 (4 to 35) mm at rest and during activity respectively. Patients in the FS group resumed normal daily activity earlier (after median 7 versus 18 days; P = 0·027) and reported significantly less discomfort. No recurrences were observed.

CONCLUSION

Mesh fixation with FS in LVHR was associated with less acute postoperative pain, discomfort and a shorter convalescence than tack fixation. Long-term follow-up is needed to show whether the effect of FS fixation persists in terms of chronic pain and recurrence.

REGISTRATION NUMBER

NCT00842842 (http://www.clinicaltrials.gov).

Arterial spin-labeling MRI can identify the presence and intensity of collateral perfusion in patients with moyamoya disease

BACKGROUND AND PURPOSE

Determining the presence and adequacy of collateral blood flow is important in cerebrovascular disease. Therefore, we explored whether a noninvasive imaging modality, arterial spin labeling (ASL) MRI, could be used to detect the presence and intensity of collateral flow using digital subtraction angiography (DSA) and stable xenon CT cerebral blood flow as gold standards for collaterals and cerebral blood flow, respectively.

METHODS

ASL and DSA were obtained within 4 days of each other in 18 patients with Moyamoya disease. Two neurointerventionalists scored DSA images using a collateral grading scale in regions of interest corresponding to ASPECTS methodology. Two neuroradiologists similarly scored ASL images based on the presence of arterial transit artifact. Agreement of ASL and DSA consensus scores was determined, including kappa statistics. In 15 patients, additional quantitative xenon CT cerebral blood flow measurements were performed and compared with collateral grades.

RESULTS

The agreement between ASL and DSA consensus readings was moderate to strong, with a weighted kappa value of 0.58 (95% confidence interval, 0.52-0.64), but there was better agreement between readers for ASL compared with DSA. Sensitivity and specificity for identifying collaterals with ASL were 0.83 (95% confidence interval, 0.77-0.88) and 0.82 (95% confidence interval, 0.76-0.87), respectively. Xenon CT cerebral blood flow increased with increasing DSA and ASL collateral grade (P<0.05).

CONCLUSIONS

ASL can noninvasively predict the presence and intensity of collateral flow in patients with Moyamoya disease using DSA as a gold standard. Further study of other cerebrovascular diseases, including acute ischemic stroke, is warranted.

Cerebral CT perfusion using an interventional C-arm imaging system: cerebral blood flow measurements

BACKGROUND AND PURPOSE

CTP imaging in the interventional suite could reduce delays to the start of image-guided interventions and help determine the treatment progress and end point. However, C-arms rotate slower than clinical CT scanners, making CTP challenging. We developed a cerebral CTP protocol for C-arm CBCT and evaluated it in an animal study.

MATERIALS AND METHODS

Five anesthetized swine were imaged by using C-arm CBCT and conventional CT. The C-arm rotates in 4.3 seconds plus a 1.25-second turnaround, compared with 0.5 seconds for clinical CT. Each C-arm scan had 6 continuous bidirectional sweeps. Multiple scans each with a different delay to the start of an aortic arch iodinated contrast injection and a novel image reconstruction algorithm were used to increase temporal resolution. Three different scan sets (consisting of 6, 3, or 2 scans) and 3 injection protocols (3-mL/s 100%, 3-mL/s 67%, and 6-mL/s 50% contrast concentration) were studied. CBF maps for each scan set and injection were generated. The concordance and Pearson correlation coefficients (ρ and r) were calculated to determine the injection providing the best match between the following: the left and right hemispheres, and CT and C-arm CBCT.

RESULTS

The highest ρ and r values (both 0.92) for the left and right hemispheres were obtained by using the 6-mL 50% iodinated contrast concentration injection. The same injection gave the best match for CT and C-arm CBCT for the 6-scan set (ρ = 0.77, r = 0.89). Some of the 3-scan and 2-scan protocols provided matches similar to those in CT.

CONCLUSIONS

This study demonstrated that C-arm CBCT can produce CBF maps that correlate well with those from CTP.

Comparison of MR and contrast venography of the cervical venous system in multiple sclerosis

BACKGROUND AND PURPOSE

MRV has been proposed as a possible screening method to identify chronic cerebrospinal venous insufficiency, which may play a role in MS. We report our initial experience comparing MRV and CV in MS patients to evaluate venous stenosis and collateral venous drainage.

MATERIALS AND METHODS

Time-of-flight and time-resolved imaging of contrast kinetics MRV and CV were performed in 39 MS patients. The presence and severity of both IJ vein caliber changes and non-IJ collaterals were graded by using a 4-point scale by 2 radiologists in an independent and blinded manner.

RESULTS

Both studies frequently showed venous abnormalities, most commonly IJ flattening at the C1 level and in the lower neck. There was moderate-to-good agreement between the modalities (κ = 0.55; 95% CI, 0.45%-0.65%). For collaterals, agreement was only fair (κ = 0.30; 95% CI, 0.09%-0.50%). The prevalence of IJ segments graded mild or worse on CV was 54%. If CV was considered a standard, the sensitivity and specificity of MRV was 0.79 (0.71-0.86) and 0.76 (0.67-0.83), respectively. Degree of stenosis was related to the severity of collaterals for CV but not for MRV.

CONCLUSIONS

IJ caliber changes were seen in characteristic locations on both MRV and CV in MS patients. Agreement between modalities was higher for stenosis than for collaterals. If CV is considered a standard, MRV performance is good but may require additional improvement before MRV can be used for screening.

Strains across the acetabular labrum during hip motion: a cadaveric model

BACKGROUND

Labral tears commonly cause disabling intra-articular hip pain and are commonly treated with hip arthroscopy. However, the function and role of the labrum are still unclear.

HYPOTHESES

(1) Flexion, adduction, and internal rotation (a position clinically defined as the position for physical examination known as the impingement test) places greatest circumferential strain on the anterolateral labrum and posterior labrum; (2) extension with external rotation (a position clinically utilized during physical examination to assess for posterior impingement and for anterior instability) places significant circumferential strains on the anterior labrum; (3) abduction with external rotation during neutral flexion-extension (the position the extremity rests in when a patient lies supine) places the greatest load on the lateral labrum.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Twelve cadaveric hips (age, 79 years) without labral tears or arthritis were studied. Hips were dissected free of soft tissues, except the capsuloligamentous structures. Differential variable reluctance transducers were placed in the labrum anteriorly, anterolaterally, laterally, and posteriorly to record circumferential strains in all 4 regions as the hip was placed in 36 different positions.

RESULTS

The posterior labrum had the greatest circumferential strains identified; the peak was in the flexed position, in adduction or neutral abduction-adduction. The greatest strains anteriorly were in flexion with adduction. The greatest strains anterolaterally were in full extension. External rotation had greater strains than neutral rotation and internal rotation. The greatest strains laterally were at 90° of flexion with abduction, and external or neutral rotation. In the impingement position, the anterolateral strain increased the most, while the posterior labrum showed decreased strain (greatest magnitude of strain change). When the hip is externally rotated and in neutral flexion-extension or fully extended, the posterior labrum has significantly increased strain, while the anterolateral labrum strain is decreased.

CONCLUSION

These are the first comprehensive strain data (of circumferential strain) analyzing the whole hip labrum. For the intact labrum, the greatest strain change was at the posterior acetabulum, whereas clinically, acetabular labral tears occur most frequently anterolaterally or anteriorly. The results are consistent with the impingement test as an assessment of anterolateral acetabular labral stress. The hyperextension-rotation test, often used clinically to assess anterior hip instability and posterior impingement, did not show a change in strain anteriorly, but did reveal an increase in strain posteriorly.

CLINICAL RELEVANCE

Although this study does not include muscular forces across the hip joint, it does provide a clue as to the stresses about the labrum through the complete range of motions of the hip, which may help in providing a better understanding of the cause of labral tears and in the protection of labral repairs.

Tumor angiogenic marker expression levels during tumor growth: longitudinal assessment with molecularly targeted microbubbles and US imaging

PURPOSE

To evaluate the use of molecularly targeted microbubbles (MBs) and ultrasonography (US) in the noninvasive assessment of the level of expression of three angiogenic markers, α(v)β(3) integrin, endoglin, and vascular endothelial growth factor receptor (VEGFR) 2, on tumor vascular endothelial cells in vivo during tumor growth.

MATERIALS AND METHODS

All procedures using laboratory animals were approved by the Institutional Administrative Panel on Laboratory Animal Care. Binding specificity of three types of targeted MBs (MB(Integrin), MB(Endoglin), MB(VEGFR2)) was tested in cell culture under flow shear stress conditions. In vivo targeted contrast material-enhanced US imaging signal using the three MB types was measured at three tumor stages (small, medium, large) in three subcutaneous cancer xenografts (breast, ovarian, pancreatic cancer) in mice (n = 54). In vivo US imaging signal was correlated with ex vivo angiogenic marker expression. Significant differences were evaluated by using the Student t, analysis of variance, Wilcoxon, and Tukey Honest Significant Difference tests.

RESULTS

Cell attachment of all three MB types was significantly (P = .016) higher compared with control MBs, and this attachment could be significantly (P = .026) decreased by blocking antibodies. Angiogenic marker-expressing cells bound significantly (P = .003) more targeted MBs than negative control cells, and MB attachment significantly (P < .001) correlated with marker expression levels on cells (ρ = 0.87). In early stage breast and ovarian cancers, in vivo targeted contrast-enhanced US demonstrated significantly (P ≤ .04) higher endoglin expression than both α(v)β(3) integrin and VEGFR2 expression, whereas in early stage pancreatic cancer, marker expressions were not significantly different (P ≥ .07). There was good correlation (ρ ≥ 0.63; P ≤ .05) between in vivo targeted contrast-enhanced US imaging signals using the three MB types and ex vivo immunoblotting results regarding expression levels of the three angiogenic markers. Immunofluorescence confirmed expression of α(v)β(3) integrin, endoglin, and VEGFR2 on tumor vascular endothelial cells.

CONCLUSION

Targeted contrast-enhanced US imaging allows noninvasive in vivo assessment of the expression levels of α(v)β(3) integrin, endoglin, and VEGFR2, which vary during tumor growth in subcutaneous cancer xenografts.

Reduced length of stay and convalescence in laparoscopic vs open sigmoid resection with traditional care: a double blinded randomized clinical trial

AIM

The effect of a laparoscopic technique without a multi-modal rehabilitation programme but with traditional postoperative care was studied in a blinded randomized trial regarding nursing time, hospital stay, pain, fatigue, need for sleep and return to normal daily activities.

METHOD

Eighteen patients with sigmoid cancer were randomly assigned to laparoscopic (n = 10) and open (n = 8) colonic resection in a double blinded trial. Length of hospital stay, fulfillment of discharge criteria, need for nursing care (information given to the patient, physical care and indirect care) and postoperative pain were recorded. Furthermore, the patients filled out a questionnaire regarding fatigue, need for sleep and return to daily activities 14 and 30 days postoperatively.

RESULTS

The laparoscopic technique reduced length of hospital stay from 7 to 4.5 days (P = 0.006), although both groups met the discharge criteria on the third postoperative day. There were no significant differences in total need for nursing time during hospitalization between the two groups (P = 0.328). The laparoscopic group had less pain 24 hours after operation (P = 0.040), and reported less fatigue and reduced need for sleep during the day 30 days after surgery when compared with open surgery (P = 0.033 and P = 0.036, respectively). Furthermore, the laparoscopic group returned significantly faster to normal daily activities after surgery (P = 0.023).

CONCLUSION

Laparoscopic surgery per se reduced hospital stay, pain and convalescence compared with open surgery in patients undergoing colonic resection.These effects were obtained without a fast track programme and without an increase in nursing staff on the general surgical ward.

A nationwide study on readmission, morbidity, and mortality after umbilical and epigastric hernia repair

BACKGROUND

Repair for umbilical and epigastric hernia is a minor and common surgical procedure. Early outcomes are not well documented.

METHODS

All patients ≥18 years operated on for umbilical or epigastric hernia in Denmark during a 2-year period (2005-2006) were analysed according to hospital stay, risk of readmission, complications, and mortality <30 days after operation. Patients with acute operations and patients having an umbilical and epigastric hernia repair secondary to other surgical procedures were excluded. Results were based on data from the National Patient Registry.

RESULTS

A total 3,431 operations (open repairs 3,165; laparoscopic repairs 266) in 3,383 patients were performed. The median hospital stay was 0 day (range 0-61 days) (open 0 day; laparoscopic 1 day); 75% stayed in hospital for 0 days, 20% for 1 day and 5% > 1 day. Readmissions occurred in 5.3% of cases (open 4.9%; laparoscopic 10.5%). In the majority of patients readmissions were due to wound-related problems (haematoma, bleeding and/or infection) (46%), seroma (19%), or pain (7%). At 30 days, complications and mortality occurred in 4.1% (open 3.7%; laparoscopic 8.2%) and 0.1% (open 0.1%; laparoscopic 0.4%), respectively.

CONCLUSION

This first prospective nationwide study on elective umbilical and epigastric hernia repair found low morbidity and mortality but a high readmission rate mostly because of wound problems, seroma formation, or pain. Future research should focus on early outcomes in terms of wound problems, seroma formation, and pain after umbilical and epigastric hernia repair.

Reduced field-of-view diffusion imaging of the human spinal cord: comparison with conventional single-shot echo-planar imaging

BACKGROUND AND PURPOSE

DWI of the spinal cord is challenging because of its small size and artifacts associated with the most commonly used clinical imaging method, SS-EPI. We evaluated the performance of rFOV spinal cord DWI and compared it with the routine fFOV SS-EPI in a clinical population.

MATERIALS AND METHODS

Thirty-six clinical patients underwent 1.5T MR imaging examination that included rFOV SS-EPI DWI of the cervical spinal cord as well as 2 comparison diffusion sequences: fFOV SS-EPI DWI normalized for either image readout time (low-resolution fFOV) or spatial resolution (high-resolution fFOV). ADC maps were created and compared between the methods by using single-factor analysis of variance. Two neuroradiologists blinded to sequence type rated the 3 DWI methods, based on susceptibility artifacts, perceived spatial resolution, signal intensity-to-noise ratio, anatomic detail, and clinical utility.

RESULTS

ADC values for the rFOV and both fFOV sequences were not statistically different (rFOV: 1.01 ± 0.18 × 10(-3) mm(2)/s; low-resolution fFOV: 1.12 ± 0.22 × 10(-3) mm(2)/s; high-resolution fFOV: 1.10 ± 0.21 × 10(-3) mm(2)/s; F = 2.747, P > .05). The neuroradiologist reviewers rated the rFOV diffusion images superior in terms of all assessed measures (P < 0.0001). Particular improvements were noted in patients with metal hardware, degenerative disease, or both.

CONCLUSIONS

rFOV DWI of the spinal cord overcomes many of the problems associated with conventional fFOV SS-EPI and is feasible in a clinical population. From a clinical standpoint, images were deemed superior to those created by using standard fFOV methods.

Single cell transcriptional profiling reveals heterogeneity of human induced pluripotent stem cells

Human induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs) are promising candidate cell sources for regenerative medicine. However, despite the common ability of hiPSCs and hESCs to differentiate into all 3 germ layers, their functional equivalence at the single cell level remains to be demonstrated. Moreover, single cell heterogeneity amongst stem cell populations may underlie important cell fate decisions. Here, we used single cell analysis to resolve the gene expression profiles of 362 hiPSCs and hESCs for an array of 42 genes that characterize the pluripotent and differentiated states. Comparison between single hESCs and single hiPSCs revealed markedly more heterogeneity in gene expression levels in the hiPSCs, suggesting that hiPSCs occupy an alternate, less stable pluripotent state. hiPSCs also displayed slower growth kinetics and impaired directed differentiation as compared with hESCs. Our results suggest that caution should be exercised before assuming that hiPSCs occupy a pluripotent state equivalent to that of hESCs, particularly when producing differentiated cells for regenerative medicine aims.

Prediction of glycosaminoglycan content in human cartilage by age, T1ρ and T2 MRI

OBJECTIVE

A relationship between T1ρ relaxation time and glycosaminoglycan (GAG) content has been demonstrated in chemically degraded bovine cartilage, but has not been demonstrated with quantitative biochemistry in human cartilage. A relationship has also been established between T2 relaxation time in cartilage and osteoarthritis (OA) severity. We hypothesized that T1ρ relaxation time would be associated with GAG content in human cartilage with normal T2 relaxation times.

METHODS

T2 relaxation time, T1ρ relaxation time, and glycosaminoglycan as a percentage of wet weight (sGAG) were measured for top and bottom regions at 7 anatomical locations in 21 human cadaver patellae. For our analysis, T2 relaxation time was classified as normal or elevated based on a threshold defined by the mean plus one standard deviation of the T2 relaxation time for all samples.

RESULTS

In the normal T2 relaxation time subset, T1ρ relaxation time correlated with sGAG content in the full-thickness and bottom regions, but only marginally in the top region alone. sGAG content decreased significantly with age in all regions.

CONCLUSION

In the subset of cartilage specimens with normal T2 relaxation time, T1ρ relaxation time was inversely associated with sGAG content, as hypothesized. A predictive model, which accounts for T2 relaxation time and the effects of age, might be able to determine longitudinal trends in GAG content in the same person based on T1ρ relaxation time maps.

Multidetector computed tomography of acute vascular injury in blunt abdominal/pelvic trauma: imaging predictors of treatment

PURPOSE

The purpose of this study was to analyze the multidetector computed tomography (MDCT) morphologic characteristics of non-aortic acute vascular injuries (AVI) in patients with blunt abdominopelvic trauma that predict treatment.

METHODS

CT scans of 65 trauma patients with non-aortic AVI were reviewed. AVI morphology was categorized as linear or round. The organ of involvement, location of hemorrhage, initial size of hematoma, and hemodynamic status were recorded. Expansion rates of the hematoma were calculated in 40 patients who had delayed imaging. Multivariate regression was used to analyze the morphologic features of AVI and treatment.

RESULTS

Patients with linear AVI were four times more likely to require aggressive treatment (surgery or embolization) than those with a round morphology, independent of the hemodynamic status. There was no main effect of the organ involved, location of hemorrhage, initial bleed size, or expansion rate on the probability of aggressive treatment.

CONCLUSION

The location, initial size, and expansion rate of AVI are not significant predictors of aggressive treatment with surgery or embolization. Linear morphology of AVI, however, is more likely to require aggressive treatment than round AVI, independent of the hemodynamic status. Linear AVI likely reflects a spurting jet of active extravasation, whereas round AVI likely represents a pseudoaneurysm or slow bleed.

Trocar site hernia after laparoscopic surgery: a qualitative systematic review

PURPOSE

There is a risk of developing a trocar site hernia (TSH) after laparoscopic surgery, but data is sparse and based mostly on retrospective studies with a short and poorly defined follow-up period. Surgical approaches and patient-related co-morbidity have also been suggested as risk factors for development of TSH. The aim of the present review was to perform a qualitative systematic analysis to estimate the incidence of TSH and to discuss the surgical and patient-related risk factors for development of TSH.

METHODS

The literature search was until 19 May 2010. Studies with TSH, defined as either operation for TSH or a hernia found during clinical follow-up, were included. We included randomised controlled trials, prospective non-controlled studies including >200 patients, and retrospective studies including >200 patients. The review was completed according to the PRISMA guidelines.

RESULTS

We included 19 studies in adults and 3 studies in paediatric patients (<18 years), and a total of 30,568 adults and 1,098 children were analysed. The overall incidence of TSH was 0-5.2%. TSH occurred most often (96%) in trocar sites of a minimum of 10 mm, located mostly in the umbilicus region (82%). Data supported a higher incidence of TSH when the trocar site fascia was not sutured, and in pre-school children undergoing a laparoscopic procedure.

CONCLUSIONS

Current data suggests a relatively low incidence of TSH but that all trocar incisions of a minimum of 10 mm should be closed. In pre-school children undergoing laparoscopic surgery, all port sites should be closed.

Effect of diclofenac on cyclooxygenase-2 levels and early breaking strength of experimental colonic anastomoses and skin incisions

BACKGROUND

Recently, there has been a focus on the effect of the nonsteroidal anti-inflammatory drugs on the anastomotic leakage rate after colorectal surgery.

METHODS

An experimental, randomized, placebo-controlled prospective study on 32 male Wistar rats was carried out. We examined the effect of diclofenac 4 mg/kg/day on the cyclooxygenase-2 (COX-2) enzyme in the anastomotic tissue and on the breaking strength of anastomotic and incisional wounds. The operation was performed with colonic resection and hand-sewn anastomosis. After 3 days, the rats were sacrificed and the breaking strength and the COX-2 content of the anastomosis were measured.

RESULTS

There was a significantly reduced level of COX-2 in the rats treated with diclofenac (p = 0.001); no significant differences in any of the breaking strength measurements and no significant correlation between COX-2 levels and breaking strength of the anastomotic or incisional wounds could be found (p = 0.073 and p = 0.727).

CONCLUSION

This study for the first time showed that a diclofenac dose of 4 mg/kg/24 h was sufficient to reduce the level of COX-2 enzymes in the anastomotic tissue in rats. This inhibition of the inflammatory response did not lead to reduced breaking strength of either anastomotic or incisional wounds. Whether there is a detrimental effect of COX inhibition on colorectal anastomoses in the clinical setting remains controversial.

Circadian aspects of post-operative morbidity and mortality

It has been well established that there exists a circadian concentration of cardiovascular, cerebrovascular and cardiopulmonary events. The aim was to describe aspects of circadian variation in relation to cardiovascular, cerebrovascular and thromboembolic diseases and to describe the literature concerning post-operative circadian disturbances. We also present the literature concerning circadian variation in post-operative morbidity and mortality. PubMed and the Cochrane database were searched for papers using a combination of 'circadian,''surgery,''post-operative,''mortality' and 'morbidity.' Eleven relevant studies were found, and seven of these were excluded due to the use of time of surgery and not time of morbidity or mortality as the main variable. The results from the four articles showed a circadian distribution of morbidity and mortality that mimics the one seen without surgery. There is a peak incidence of myocardial ischemia, fatal thromboembolism and sudden unexpected death in the morning hours. A circadian variation exists in post-operative morbidity and mortality. The observed circadian variation in post-operative morbidity and mortality may warrant a chronopharmacological approach to patients in the perioperative period. The underlying pathophysiological mechanisms should be the focus for future studies.

No effect of melatonin on oxidative stress after laparoscopic cholecystectomy: a randomized placebo-controlled trial

BACKGROUND

Melatonin, an endogenous circadian regulator, also has antioxidant and anti-inflammatory properties. The aim of this study was to evaluate the antioxidative effect of melatonin in patients undergoing laparoscopic cholecystectomy.

METHODS

Patients were randomized to receive 10 mg melatonin or placebo during surgery. Blood samples for analysis of malondialdehyde (MDA), ascorbic acid (AA), total ascorbic acid (TAA) dehydroascorbic acid (DHA) and C-reactive protein (CRP) were collected pre-operatively and at 5 min, 6 h and 24 h after operation.

RESULTS

Twenty patients received melatonin and 21 patients received placebo during surgery. No significant differences were observed between the groups in the oxidative stress variables MDA, TAA, AA and DHA or in the inflammatory variable CRP (repeated-measures ANOVA, P>0.05 for all variables).

CONCLUSIONS

Administration of 10 mg melatonin did not reduce variables of oxidative stress in patients undergoing elective laparoscopic cholecystectomy.

Reinforcement probability and ordinal position of response in fixed-interval schedules

Four rats pressed levers and received food pellets under fixed-interval reinforcement schedules of 20, 60, and 180 seconds. The number of responses in each interval was recorded. From these data, the probability of reinforcement was determined as a function of response count. These functions were generally increasing. This finding is consistent with previous suggestions that increasing response rates within fixed intervals may be a function of response count in addition to or instead of elapsed or remaining time.

Consistency of signal intensity and T2* in frozen ex vivo heart muscle, kidney, and liver tissue

PURPOSE

To investigate tissue dependence of the MRI-based thermometry in frozen tissue by quantification and comparison of signal intensity and T2* of ex vivo frozen tissue of three different types: heart muscle, kidney, and liver.

MATERIALS AND METHODS

Tissue samples were frozen and imaged on a 0.5 Tesla MRI scanner with ultrashort echo time (UTE) sequence. Signal intensity and T2* were determined as the temperature of the tissue samples was decreased from room temperature to approximately -40 degrees C. Statistical analysis was performed for (-20 degrees C, -5 degrees C) temperature interval.

RESULTS

The findings of this study demonstrate that signal intensity and T2* are consistent across three types of tissue for (-20 degrees C, -5 degrees C) temperature interval.

CONCLUSION

Both parameters can be used to calculate a single temperature calibration curve for all three types of tissue and potentially in the future serve as a foundation for tissue-independent MRI-based thermometry.

Antiangiogenic cancer therapy: monitoring with molecular US and a clinically translatable contrast agent (BR55)

PURPOSE

To develop and test human kinase insert domain receptor (KDR)-targeted microbubbles (MBs) (MB(KDR)) for imaging KDR at the molecular level and for monitoring antiangiogenic therapy in a human colon cancer xenograft tumor model in mice.

MATERIALS AND METHODS

Animal studies were approved by the Institutional Administrative Panel on Laboratory Animal Care. A heterodimeric peptide that binds to human KDR with low nanomolar affinity (K(D) = 0.5 nmol/L) was coupled onto the surface of perfluorobutane-containing lipid-shelled MBs (MB(KDR)). Binding specificity of MB(KDR) to human KDR and cross-reactivity with murine vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) were tested in cell culture under flow shear stress conditions (at 100 sec(-1)). In vivo binding specificity of MB(KDR) to VEGFR2 was tested in human LS174T colon cancer xenografts in mice with a 40-MHz ultrasonographic (US) transducer. Targeted contrast material-enhanced US imaging signal by using MB(KDR) was longitudinally measured during 6 days in tumors with (n = 6) and without (n = 6) antiangiogenic treatment (anti-VEGF antibody). Ex vivo VEGFR2 staining and microvessel density analysis were performed. Significant differences were evaluated (t, Mann-Whitney, or Wilcoxon test).

RESULTS

Cell culture experiments showed four times greater binding specificity of MB(KDR) to human KDR and cross-reactivity to murine VEGFR2 (P < or = .01). In vivo imaging signal was more than three times higher (P = .01) with MB(KDR) compared with control MBs and decreased significantly (approximately fourfold lower, P = .03) following in vivo receptor blocking with anti-VEGFR2 antibody. One day after initiation of antiangiogenic therapy, imaging signal was significantly decreased (approximately 46% lower, P = .02) in treated versus untreated tumors; it remained significantly lower (range, 46%-84% decreased; P = .038) during the following 5 days. Microvessel density was significantly reduced (P = .04) in treated (mean, 7.3 microvessels per square millimeter +/- 4.7 [standard deviation]) versus untreated tumors (mean, 22.0 microvessels per square millimeter +/- 9.4); VEGFR2 expression was significantly decreased (>50% lower, P = .03) in treated tumors.

CONCLUSION

Human MB(KDR) allow in vivo imaging and longitudinal monitoring of VEGFR2 expression in human colon cancer xenografts.

Improving dynamic susceptibility contrast MRI measurement of quantitative cerebral blood flow using corrections for partial volume and nonlinear contrast relaxivity: A xenon computed tomographic comparative study

PURPOSE

To test whether dynamic susceptibility contrast MRI-based CBF measurements are improved with arterial input function (AIF) partial volume (PV) and nonlinear contrast relaxivity correction, using a gold-standard CBF method, xenon computed tomography (xeCT).

MATERIALS AND METHODS

Eighteen patients with cerebrovascular disease underwent xeCT and MRI within 36 h. PV was measured as the ratio of the area under the AIF and the venous output function (VOF) concentration curves. A correction was applied to account for the nonlinear relaxivity of bulk blood (BB). Mean CBF was measured with both techniques and regression analyses both within and between patients were performed.

RESULTS

Mean xeCT CBF was 43.3 +/- 13.7 mL/100g/min (mean +/- SD). BB correction decreased CBF by a factor of 4.7 +/- 0.4, but did not affect precision. The least-biased CBF measurement was with BB but without PV correction (45.8 +/- 17.2 mL/100 g/min, coefficient of variation [COV] = 32%). Precision improved with PV correction, although absolute CBF was mildly underestimated (34.3 +/- 10.8 mL/100 g/min, COV = 27%). Between patients correlation was moderate even with both corrections (R = 0.53).

CONCLUSION

Corrections for AIF PV and nonlinear BB relaxivity improve bolus MRI-based CBF maps. However, there remain challenges given the moderate between-patient correlation, which limit diagnostic confidence of such measurements in individual patients.

Uncluttered single-image visualization of the abdominal aortic vessel tree: method and evaluation

PURPOSE

The authors develop a method to visualize the abdominal aorta and its branches, obtained by CT or MR angiography, in a single 2D stylistic image without overlap among branches.

METHODS

The abdominal aortic vasculature is modeled as an articulated object whose underlying topology is a rooted tree. The inputs to the algorithm are the 3D centerlines of the abdominal aorta, its branches, and their associated diameter information. The visualization problem is formulated as an optimization problem that finds a spatial configuration of the bounding boxes of the centerlines most similar to the projection of the input into a given viewing direction (e.g., anteroposterior), while not introducing intersections among the boxes. The optimization algorithm minimizes a score function regarding the overlap of the bounding boxes and the deviation from the input. The output of the algorithm is used to produce a stylistic visualization, made of the 2D centerlines modulated by the associated diameter information, on a plane. The authors performed a preliminary evaluation by asking three radiologists to label 366 arterial branches from the 30 visualizations of five cases produced by the method. Each of the five patients was presented in six different variant images, selected from ten variants with the three lowest and three highest scores. For each label, they assigned confidence and distortion ratings (low/medium/high). They studied the association between the quantitative metrics measured from the visualization and the subjective ratings by the radiologists.

RESULTS

All resulting visualizations were free from branch overlaps. Labeling accuracies of the three readers were 93.4%, 94.5%, and 95.4%, respectively. For the total of 1098 samples, the distortion ratings were low: 77.39%, medium: 10.48%, and high: 12.12%. The confidence ratings were low: 5.56%, medium: 16.50%, and high: 77.94%. The association study shows that the proposed quantitative metrics can predict a reader's subjective ratings and suggests that the visualization with the lowest score should be selected for readers.

CONCLUSIONS

The method for eliminating misleading false intersections in 2D projections of the abdominal aortic tree conserves the overall shape and does not diminish accurate identifiability of the branches.

Nationwide study of early outcomes after incisional hernia repair

Background

There are no nationwide studies on early outcomes after incisional hernia repair.

Methods

This study included all patients aged 18 years or more who had surgery for incisional hernia in Denmark between 1 January 2005 and 31 December 2006, and analysed clinical outcomes within 30 days of surgery. Patients having acute operations and those whose hernia repair was secondary to other procedures were excluded.

Results

Of a total of 2896 incisional hernia repairs (1872 open, 1024 laparoscopic), 2754 (95·1 per cent) were for primary hernia and 142 (4·9 per cent) for recurrence. The median hospital stay was 1 (range 0–88) day (open, 1 day; laparoscopic, 2 days); 10·0 per cent stayed for more than 6 days. Some 11·2 per cent of patients were readmitted (open, 10·1 per cent; laparoscopic, 13·1 per cent). Major complications were observed in 3·5 per cent (open, 2·8 per cent; laparoscopic, 4·8 per cent) with a total morbidity rate of 10·7 per cent (open, 10·1 per cent; laparoscopic, 11·8 per cent). The mortality rate was 0·4 per cent (open, 0·2 per cent; laparoscopic, 0·7 per cent). Morbidity and mortality were not related to surgical volume.

Conclusion

Outcomes after incisional hernia repair seem unsatisfactory.

Trends in 3-D CT Postprocessing

PURPOSE

The increasing number of multidetector CT scanners in radiology departments has intensified demand for 3-D imaging. This study sought to reveal the frequency and type of postprocessing tasks being performed by computed tomography (CT) technologists by discussing the longitudinal results of the American Registry of Radiologic Technologists (ARRT) CT practice analysis surveys from 1993 to 2007.

METHOD

In 1993, 2001 and 2007, the ARRT mailed CT job analysis surveys to a national randomized sample of 1000 radiologic technologists per year who were employed full time in CT, for a combined total of 3000. A usable sample of 1476 responses from the 3 surveys revealed technologists' level of responsibility for a variety of CT tasks, including 3-D imaging.

RESULTS

The proportion of respondents responsible for 3-D imaging increased from 47% in 1993 to 74% in 2001 and to 82% in 2007 (P< .001). This increase occurred in all employment settings (P < .001) and department sizes (P < .001), including small departments. Daily frequency of occurrence grew from 4% in 1993 to 11% in 2001 and 53% in 2007 (P< .001).

CONCLUSION

Routine 3-D postprocessing has become typical practice in radiology CT departments across all employment settings.

Inadequate preoperative colonic evaluation for synchronous colorectal cancer

BACKGROUND AND AIMS

Synchronous cancers (SC) are well known (2-11%) in patients with colorectal carcinoma (CRC). One study has shown that intraoperative palpation can miss up to 69% of the SC while other studies have shown altered planned surgical procedure due to preoperatively diagnosed synchronous lesions in 11-44%. The purpose of this study was to review all patients having surgery for CRC in our department since 2001, and to evaluate the extent of the perioperative colonic evaluation.

MATERIALS AND METHODS

The records of all patients operated for CRC between Jan. 2001 and Dec. 2007 in our department were reviewed. Only patients with CRC were included. Information regarding pre-, per- and postoperative colonic evaluation were obtained and occurrences of SC were evaluated.

RESULTS

Of the 534 patients included 124 (23%) patients had an impassable stenosis. Full preoperative colonic evaluation (FPCE) were done in 305 (26%) patients without stenosis. In 36 patients 39 SC were diagnosed. Seven SC were diagnosed postoperatively, of which five patients never had a FPCE. Three of these five patients had an inoperable SC, one patient died due to anastomosis leakage following re-operation and one patient had pulmonary embolism as a complication to re-operation.

CONCLUSIONS

The results show that many patients (78%) never underwent FPCE, but also that many of these patients never had a full postoperative colonic evaluation. SC being overlooked can lead to increased morbidity and the possibility of advanced staging of the cancer which is also exemplified in this study.

Bevacizumab plus interferon-alpha versus interferon-alpha monotherapy in patients with metastatic renal cell carcinoma: Results of overall survival for CALGB 90206

LBA5019

Background: Bevacizumab (BEV) plus interferon alpha (IFN) demonstrated a superior objective response rate and progression-free survival (PFS) versus IFN monotherapy in renal cell carcinoma (RCC) patients in 2 phase III trials. The primary objective of CALGB 90206 was to compare overall survival (OS) for advanced RCC patients receiving BEV plus IFN or IFN alone. Methods: Patients with previously-untreated, metastatic RCC with a clear cell component and Karnofsky performance status of ≥ 70% were eligible. Patients were prospectively randomized to receive BEV (10 mg/kg intravenously every 2 weeks) plus IFN (9 million units subcutaneously three times weekly) or the same dose and schedule of IFN as monotherapy. Randomization was stratified by nephrectomy status and number of MSKCC adverse features. The primary endpoint was OS, defined as the time from randomization to death due to any cause. The trial was designed with 86% power to detect a hazard ratio (HR) of 0.76, assuming a two-sided type I error of 0.05. The primary analysis was an intent-to-treat approach using the stratified log-rank statistic, and the present analysis was based on the target number of 588 deaths. Results: Between October 2003 and July 2005, 732 patients were enrolled; 369 pts to BEV plus IFN and 363 pts to IFN monotherapy. The median duration of follow up among censored patients was 46.2 months (IQR=45.2–48.2). The median OS was 18.3 months (95% CI; 16.5–22.5) for BEV plus IFN and 17.4 months (95% CI; 14.4–20.0, unstratified log rank p = 0.097) for IFN monotherapy. The stratified HR was 0.86 (95% CI; 0.73–1.01) for BEV plus IFN compared to IFN (stratified log-rank p = 0.069). The median OS for BEV plus IFN versus IFN was 32.5 vs. 33.5 months (p = 0.524) for MSKCC good risk, 17.7 vs. 16.1 months (p = 0.174) for intermediate risk and 6.6 vs. 5.7 months (p = 0.245) for poor risk patients. The median PFS was 8.4 months vs. 4.9 months (p<0.0001). Fifty-three percent of patients received subsequent systemic therapy. Conclusions: The addition of BEV to IFN significantly improves the objective response rate and PFS versus IFN monotherapy. Overall survival favored the BEV plus IFN arm, not meeting pre-defined criteria for significance.

[Table: see text]

Lower extremity CT angiography (CTA): initial evaluation of a knowledge-based centerline estimation algorithm for femoro-popliteal artery (FPA) occlusions

RATIONALE AND OBJECTIVES

Existing density- and gradient-based automated centerline-extraction algorithms fail in severely diseased or occluded arterial segments for the generation of curved planar reformations (CPRs). We aimed to quantitatively and qualitatively assess the precision of a knowledge-based centerline-extraction algorithm in patients with occluded femoro-popliteal artery (FPA).

MATERIAL AND METHODS

Computed tomography angiograms of 38 FPA occlusions (mean length 120 mm) were retrospectively identified. Reference centerlines were determined as the mean of eight manual expert readings. Each occlusion was also interpolated using a new knowledge-based algorithm (partial vector space projection [PVSP]), which uses shape information extracted from a separate database of 30 nondiseased FPAs. Precision of PVSP was quantified as the maximum departure error (MDE) from the standard of reference and the proportion of the interpolated centerlines remaining within an assumed vessel radius of 3 mm. Multiple regression method was used to determine the factors predicting the precision of the algorithm. CPR quality was independently assigned by two readers.

RESULTS

The mean MDE (in mm) for occlusion lengths of <50 mm, 50-100 mm, 100-200 mm, and >200 mm was 0.95, 1.19, 1.40, and 2.25, for manual readings and 1.68, 2.90, 9.43, and 19.95 for PVSP, respectively. MDEs of the algorithm were completely contained within 3 mm of the assumed vessel radius in 20 of 38 occlusions. CPR quality was rated diagnostic by both readers in 23 of 38 occlusions.

CONCLUSION

Shape-based centerline extraction of FPA occlusions in lower extremity CTA is feasible, and independent from local density and gradient information. PVSP centerline extraction allows interpolation of occlusions up to 100 mm within the variability of manually derived centerlines.

Ixabepilone, mitoxantrone, and prednisone in patients with metastatic castration-resistant prostate cancer refractory to docetaxel-based therapy: A phase II study of the DOD Prostate Cancer Clinical Trials Consortium

5058

Background: Mitoxantrone (M) plus prednisone (P) and ixabepilone (Ix) each have modest, non cross-resistant activity as second line chemotherapy regimens in docetaxel-refractory patients with CRPC. These agents were therefore combined in a phase I study which demonstrated anti-cancer activity and defined the recommended phase II dose used in this trial. Methods: Patients with metastatic CRPC and progression after 3 or more cycles of docetaxel were enrolled in a phase II multicenter study of the combination of prednisone 5 mg BID, Ix (35 mg/m2) and M (12 mg/m2) administered intravenously on day 1 every 21 days, with pegfilgrastim (6 mg on day 2) support. Results: To date, 43 pts have been enrolled and have received a median of 4 cycles. Of 37 patients currently evaluable for response, 14 (38%; 95% CI: 22–55%) have had a confirmed ≥50% decline in PSA and 19 (51%; 95% CI 34–68%) have had a confirmed ≥30% decline in PSA. Two of 15 patients with evaluable measurable disease (13%) have had a RECIST-defined objective response. All 43 patients are evaluable for toxicity. Grade 3 or 4 neutropenia was seen in 6 pts (17%) and grade 3 or 4 thrombocytopenia was seen in 3 (8%). Nonhematologic grade 3/4 events possibly related to study drug have included grade 3 fatigue (3 pts), grade 3 pneumonia (2 pts), and grade 3 atrial fibrillation, grade 4 myocardial infarction, grade 4 prostatitis, grade 3 nausea/vomiting, grade 3 neuropathy, grade 3 elevated transaminases, grade 3 dizziness, grade 3 dehydration, grade 3 shortness of breath, and grade 4 vasovagal syncope (1 pt each). Grade 2 neuropathy has been seen in 4 patients. Conclusions: The Ix, M, P regimen is active as second-line therapy in CRPC patients with progressive disease after docetaxel therapy and is reasonably well tolerated. Further investigation of this regimen is warranted. This study was supported in part by CTEP/NCI and the DOD Prostate Cancer Clinical Trials Consortium.

[Table: see text]

Bevacizumab plus interferon-alpha versus interferon-alpha monotherapy in patients with metastatic renal cell carcinoma: Results of overall survival for CALGB 90206

LBA5019

The full, final text of this abstract will be available in Part II of the 2009 ASCO Annual Meeting Proceedings, distributed onsite at the Meeting on May 30, 2009, and as a supplement to the June 20, 2009, issue of the Journal of Clinical Oncology.

[Table: see text]

COLOR II. A randomized clinical trial comparing laparoscopic and open surgery for rectal cancer

INTRODUCTION

Laparoscopic resection of rectal cancer has been proven efficacious but morbidity and oncological outcome need to be investigated in a randomized clinical trial.

TRIAL DESIGN

Non-inferiority randomized clinical trial.

METHODS

The COLOR II trial is an ongoing international randomized clinical trial. Currently 27 hospitals from Europe, South Korea and Canada are including patients. The primary endpoint is loco-regional recurrence rate three years post-operatively. Secondary endpoints cover quality of life, overall and disease free survival, post-operative morbidity and health economy analysis.

RESULTS

By July 2008, 27 hospitals from the Netherlands, Belgium, Germany, Sweden, Spain, Denmark, South Korea and Canada had included 739 patients. The intra-operative conversion rate in the laparoscopic group was 17%. Distribution of age, location of the tumor and radiotherapy were equal in both treatment groups. Most tumors are located in the mid-rectum (41%).

CONCLUSION

Laparoscopic surgery in the treatment of rectal cancer is feasible. The results and safety of laparoscopic surgery in the treatment of rectal cancer remain unknown, but are subject of interim analysis within the COLOR II trial. Completion of inclusion is expected by the end of 2009.

TRIAL REGISTRATION

Clinicaltrials.gov, identifier: NCT00297791 (www.clinicaltrials.gov).

Imaging gene expression in human mesenchymal stem cells: from small to large animals

PURPOSE

To evaluate the feasibility of reporter gene imaging in implanted human mesenchymal stem cells (MSCs) in porcine myocardium by using clinical positron emission tomography (PET)-computed tomography (CT) scanning.

MATERIALS AND METHODS

Animal protocols were approved by the Institutional Administrative Panel on Laboratory Animal Care. Transduction of human MSCs by using different doses of adenovirus that contained a cytomegalovirus (CMV) promoter driving the mutant herpes simplex virus type 1 thymidine kinase reporter gene (Ad-CMV-HSV1-sr39tk) was characterized in a cell culture. A total of 2.25 x 10(6) transduced (n = 5) and control nontransduced (n = 5) human MSCs were injected into the myocardium of 10 rats, and reporter gene expression in human MSCs was visualized with micro-PET by using the radiotracer 9-(4-[fluorine 18]-fluoro-3-hydroxymethylbutyl)-guanine (FHBG). Different numbers of transduced human MSCs suspended in either phosphate-buffered saline (PBS) (n = 4) or matrigel (n = 5) were injected into the myocardium of nine swine, and gene expression was visualized with a clinical PET-CT. For analysis of cell culture experiments, linear regression analyses combined with a t test were performed. To test differences in radiotracer uptake between injected and remote myocardium in both rats and swine, one-sided paired Wilcoxon tests were performed. In swine experiments, a linear regression of radiotracer uptake ratio on the number of injected transduced human MSCs was performed.

RESULTS

In cell culture, there was a viral dose-dependent increase of gene expression and FHBG accumulation in human MSCs. Human MSC viability was 96.7% (multiplicity of infection, 250). Cardiac FHBG uptake in rats was significantly elevated (P < .0001) after human MSC injection (0.0054% injected dose [ID]/g +/- 0.0007 [standard deviation]) compared with that in the remote myocardium (0.0003% ID/g +/- 0.0001). In swine, myocardial radiotracer uptake was not elevated after injection of up to 100 x 10(6) human MSCs (PBS group). In the matrigel group, signal-to-background ratio increased to 1.87 after injection of 100 x 10(6) human MSCs and positively correlated (R(2) = 0.97, P < .001) with the number of administered human MSCs.

CONCLUSION

Reporter gene imaging in human MSCs can be translated to large animals. The study highlights the importance of co-administering a "scaffold" for increasing intramyocardial retention of human MSCs.