Imaging criteria for assessing tumour response: RECIST, mRECIST, Cheson

Most methods define a limited number of "target" lesions to be measured and other "non-target" lesions to be evaluated qualitatively. RECIST criteria are the most widely used although other criteria have been proposed that are derived from them based on size alone, or size and attenuation. Modified RECIST (mRECIST) criteria only concern hepatocellular carcinoma and only take into account the viable portion (enhanced after injection during the arterial phase). Cheson criteria are more complex as target lesions are defined differently depending on the organ (lymph nodes, liver or spleen, other organs), and involve both CT and PET scans, as well as the clinical examination and bone marrow biopsy.

What is the association between quality of treatment for depression and patient outcomes? A cohort study of adults consulting in primary care

BACKGROUND

The association between adequate treatment for a Major Depressive Episode (MDE) and improvements in depressive symptoms is not well established in naturalistic practice conditions. The main objective of this study was to examine the association between receiving at least one minimally adequate treatment for MDE (i.e. according to clinical guidelines) in the previous 12 months and evolution of depressive symptoms at 6- and 12-months. Associations with receiving pharmacotherapy and/or psychotherapy and the role of severity of depression were examined.

METHODS

This cohort study included 908 adults meeting criteria for previous-year MDE and consulting at one of 65 primary care clinics in Quebec, Canada. Multilevel analyses were performed.

RESULTS

Results show that (i) receiving at least one minimally adequate treatment for depression was associated with greater improvements in depression symptoms at 6 and at 12 months; (ii) adequate pharmacotherapy and adequate psychotherapy were both associated with greater improvements in depression symptoms, and (iii) the association between adequate treatment and improvement in depression symptoms varied as a function of severity of symptoms at the time of inclusion in the cohort with worse symptoms at the time of inclusion being associated with greater reductions at 6 and 12 months.

LIMITATIONS

Measures are self-reported. Participants were recruited at different stages over the course of their MDE.

CONCLUSIONS

This study shows that adequate treatment for depression is associated with improvements in depressive symptoms in naturalistic primary care practice conditions, but that those with more severe depressive symptoms are more likely to receive adequate treatment and improve across time.

Dynamic Contrast Enhanced Optical Imaging of Capillary Leakage

We studied in vivo the vascular permeability of two fluorescent contrast agents in three types of capillary, using a fibered confocal fluorescence microscopy system. Mice were imaged after injection of a macromolecular (albumin FITC 68,000 daltons) or low-molecular-weight contrast agent (FITC 389 daltons). We studied continuous capillaries in muscles (FITC n = 4, albumin FITC n = 6), fenestrated capillaries in mesenteries (FITC n = 8, albumin FITC n = 10), and discontinuous capillaries in xenografted tumors (FITC n = 2, albumin FITC n = 4). Signal intensity (SI) was measured in capillary and interstitial regions, and time-enhancement curves were drawn. Two-compartment models were constructed to determine quantitative microcirculation parameters. The arrival of the bolus of the two different contrast agents was observed in mesentery and muscle capillaries but not in tumor capillaries. Interstitial leakage of the low-molecular-weight contrast agent was observed almost instantaneously, whereas the macromolecular agent remained within the vessels. Signal intensity declined over the observation period, specifically in the tumor. No quantitative microcirculation parameters could be obtained with either of two bi compartmental models, owing to model instability. This study shows that the microcirculation can be reproducibly observed in different types of capillary in vivo with this fibered fluorescence imaging device. Further work is required to quantify microvascular parameters.

Role of reactive oxygen species during hypertension in response to chronic antiangiogenic factor (sFlt-1) excess in pregnant rats

BACKGROUND

Preeclampsia is associated with increased levels of reactive oxygen species (ROS) and the antiangiogenic factor, soluble fms-like tyrosine kinase-1 (sFlt-1). Moreover, recent studies have indicated that chronic sFlt-1 excess causes hypertension in pregnant animals. The purpose of this study was to evaluate the role of ROS in mediating sFlt-1-induced hypertension in the pregnant rat.

METHODS

Mean arterial pressure (MAP), and plasma sFlt-1 and tissue ROS levels were measured in the following groups: (i) pregnant controls; (ii) sFlt-1-treated pregnant rats; (iii) Tempol-treated pregnant rats; (iv) sFlt-1- and Tempol-treated pregnant rats.

RESULTS

MAP increased from 104 ± 2 mm Hg in pregnant control rats to 118 ± 3 mm Hg (P = 0.002) in sFlt-1-infused rats. Basal and nicotinamide adenine dinucleotide phosphate (NADPH)-stimulated levels of tissue ROS were increased in response to excess sFlt-1 during pregnancy. Pretreatment with Tempol attenuated oxidative stress and hypertension in response to sFlt-1.

CONCLUSIONS

ROS play an important role in mediating hypertension in response to chronic sFlt-1 excess during pregnancy.

[Hemolytic uremic syndrome with an atypical presentation]

The hemolytic uremic syndrome (HUS) is rare and of guarded prognosis in adults. It expresses a renal thrombotic microangiopathy. We report the case of a young patient whose clinical presentation and exploration make a diagnosis of HUS likely. The atypical presentation provides an opportunity not only to discuss all diagnostic elements based on recent pathophysiological hypotheses, but also to highlight recommendations for the management of this severe disease.

Dynamic contrast-enhanced CT (DCE-CT) as an early biomarker of response in metastatic renal cell carcinoma (mRCC) under anti-angiogenic treatment

14003

Background: Evaluation of treatment response for cancer relies on application of criteria based on size such RECIST. However, changes in size are often delayed and small. An accurate and early evaluation of tumor vascular characteristics would allow selection of patients (pts) who would most likely benefit of these therapies and early detection of treatment response to tailor therapy on an individual basis. Changes in tumor vascular parameters were quantified using dynamic contrast-enhanced computed tomography (DCE-CT) as a biomarker for tumor angiogenesis. Methods: A total of 44 mRCC pts were enrolled in an imaging study corollary of two phase III trials evaluating efficacy of anti-angiogenic drugs: sorafenib (N=9) vs. placebo (N=13), or sunitinib (N=17) vs. interferon (N=5). Perfusion CT acquisitions after injection of 80 ml of iodinated contrast agent were performed on a single “functional metastatic target” before treatment and every 6 weeks for follow-up. Microvascular parameters of the functional target were calculated using a dedicated software based on compartmental models: tumor blood flow (TBF) (ml/min/100g), tumor blood volume (TBV) (%), vascular permeability (VP) (ml/min/100g) and mean transit time (MTT) (s). These parameters were correlated to the best treatment response as evaluated by the size variation of the RECIST targets. Results: Among the 26 treated pts, there was a statistically significant drop in TBF and TBV as early as the first cycle of treatment (respectively -50%, p=0.03 and -51%, p<0.01) compared to pre-treatment, showing the biological effect of the drug on tumor vascularity. There was a significantly higher drop in TBF and TBV in pts who would be later classified as responders (N=16) vs. non-responders (N=10) after the first cycle of treatment (-66% vs. -6%, p=0.02; -60% vs. -26.5%, p=0.04). The changes in MTT and VP were not correlated to the best response. Conclusions: The functional imaging biomarkers TBF and TBV quantified by DCE-CT detect the biological effect of anti-angiogenic drugs on tumor vessels. TBF appears as very early predictor of mRCC response to anti-angiogenic drugs supporting the hypothesis that DCE-CT may constitute a surrogate biomarker of angiogenesis inhibition.

No significant financial relationships to disclose.

Relation between lactate dehydrogenase (LDH) during two first cycles in patients with metastatic renal cell carcinoma (mRCC) treated with sunitinib (SU)

14079

Background: LDH is a biomarker of cellular turn over. We evaluated LDH as a surrogate marker of tumor response and tumor necrosis during first cycles of SU. Methods: This is a single center study of immunorefractory patients with mRCC treated in second line with SU (50 mg, 4 weeks on, 2 weeks off). All patients performed CT scan and had serially measured tumor necrosis. Tumor response using the RECIST criteria was evaluated at the end of cycle 2 (C2). Tumor necrosis index was calculated at baseline, at the end of cycle 1 (C1) and C2 by measuring the percent area of the tumor with no enhancement after injection using an electronic calliper. LDH was measured at baseline (D1) and at the end (D28) of C1 and C2 using LD 200 kit on Synchron LX20 (Beckman Coulter). Relations between LDH and tumor response were studied using multivariate analysis of variance (MANOVA) with repeated measures and between LDH and tumor necrosis using Pearson correlation test. Results: Between Feb 2005 and Aug 2006, 56 patients were analyzed (75% men,), 91% Clear Cell Carcinoma. Mean age was 59 years (range: 30–81) and 62% has a performance status ECOG of 0. Median number of metastatic sites was 2 and mean hemoglobin level was 12.7 gr/dl. After C2, 12 (21%) partial responses, 35 (63%) stable diseases and 9 (16%) progressive diseases were noted. Results of LDH are summarized in the table . Mean LDH was statistically different between along time (p < 0.0001). LDH levels were statistically different between responders-stables and progressors patients (p = 0.004). There is a trend for a statistical relation between the index of necrosis and the tumor response measured by RECIST criteria (p = 0.08). No correlation was found between LDH and tumor necrosis. Conclusions: LDH level is higher in progressors compared to responders-stables patients. LDH level is not correlated to tumor necrosis measured by CT scan.

[Table: see text]

No significant financial relationships to disclose.

Impact of Beta-Blocker Treatment and the Nutritional Status on Glycemic Response During Exercise in Type 2 Diabetic Patients

Background/Objective: More than 60% of type 2 diabetic individuals present with hypertension and have higher risk of cardiac complications. In addition to behavioural modifications, such as healthy food choices and regular physical activity, beta-blocker (BB) treatment may be considered in order to reduce morbidity and mortality especially following a cardiovascular event. However, this medication is generally associated with a deleterious impact on glucose metabolism. To assess the impact of a BB treatment on glucose response in type 2 diabetic patients exempt of cardiovascular complications. Methods: Six sedentary men, treated with diet and/or a hypoglycemic agent performed four exercise sessions at 60% of their VO2 peak, in the fasted state or 2 hours after a standardized breakfast, with and without BB (Atenolol 100 mg id for five consecutive days). Blood samples were assayed during the resting period, at 15-minutes intervals during the exercise session and the recovery period. Results: A reduction of blood glucose levels was observed following the exercise session performed in the postabsorptive state (41% and 37% reduction with and without BB treatment respectively; P < 0.01). One hour of exercise performed in the fasted state had minimal impact on glucose and insulin levels, with or without BB. BB treatment was not associated with increased baseline blood glucose or insulin levels in the fasted or the postabsorptive situation. Conclusion: These results suggest that the nutritional status has a more important impact on plasma glucose and insulin modulation than short-term use of BB per se.

Tumor angiogenesis: pathophysiology and implications for contrast-enhanced MRI and CT assessment

The process of tumor neoangiogenesis plays a central role in the growth and spread of tumors. It is currently a leading theme in oncology, and many new drugs targeting the tumor neoangiogenic process are under development. Expanding tumors become hypoxic and tumor cells express transcription factors, such as the hypoxia-inducible factor (HIF), which induce the release of proangiogenic growth factors such as vascular endothelial growth factors (VEGF) and transforming growth factors that promote the formation of new capillaries by recruiting, activating, and stimulating endothelial cells. Activated endothelial cells secrete matrix metalloproteases, which degrade the basement membrane and the extracellular matrix, and adhesion receptors such as integrins alphavbeta(3), which allow their migration into the extracellular matrix toward the tumor cells. The newly grown vessels are immature and differ from normal capillaries. They are tortuous and irregular, resulting in poorly efficient perfusion, they are leaky (especially to macromolecules), and they are independent of the normal mechanisms of regulation of the capillary blood flow. Moreover, tumor microcirculation is heterogeneous. Evaluation of angiogenesis can be used as a prognostic marker to evaluate the aggressiveness of tumor and as a potential predictive marker of antiangiogenic treatment response. Histopathologic techniques of microvascular density indexes require invasive tissue sampling and need to be standardized. Hemodynamic characteristics of immature neovessels can be noninvasively assessed by dynamic contrast-enhanced magnetic resonance imaging or computed tomography. Tissue enhancement depends on arterial input function, kinetic of distribution of blood into the capillary bed, leakage across the capillary walls, and volume of the interstitial space. Pharmacodynamic models allow the evaluation of microvascular parameters of tissue blood flow, tissue blood volume, tissue interstitial volume, mean transit time, and permeability by surface of capillary wall. Methods based on dynamic contrast enhancement have been shown to correlate with conventional outcome methods such as histopathologic studies and survival. Radiologists must be convinced that, by using this emerging and promising approach, it is becoming possible to gain functional information during routine tumor imaging.

[Esophageal disease: is cross sectional imaging contributive?]

For a long time, esophagography and endoscopy were the major diagnostic tests used for evaluation of the esophagus. Now, the development of computed tomography, endosonography and MR imaging has permitted more comprehensive evaluation of esophageal diseases. Cross sectional imaging is essential to evaluate the relationship between esophageal lesions and adjacent mediastinal structures and to evaluate the thickness of the esophageal wall.