Peripheral lung cancer: relationship between multi-slice spiral CT perfusion imaging and tumor angiogenesis and cyclin D1 expression

Differential Diagnosis of Pathological Type of Peripheral Lung Cancer with Multimodal Contrast-Enhanced Ultrasound

OBJECTIVE

The goal of the work described here was to investigate the role of multimodal contrast-enhanced ultrasound in the differential diagnosis of peripheral lung cancer.

METHODS

From April 2017 to July 2021, 109 patients with confirmed pulmonary malignant lesions who underwent CEUS examination were involved in our study. Seven patients were excluded because of the short duration of CEUS video or unsatisfactory imaging. Finally,102 patients with peripheral lung cancer were enrolled in this study. The maximum diameter of the lesions ranged from 1.6 to 13.0 cm (mean 6.2 ± 2.3 cm). On the basis of the pathological results, the patients were divided into the small cell lung cancer (SCLC) group and non-small cell lung cancer (NSCLC) group (including adenocarcinoma, lung squamous cell carcinoma and large cell neuroendocrine carcinoma). A Logiq E9 ultrasonic machine equipped with a 3.5 to 5.0 MHz C5-1 probe was used. Patient clinical information, CEUS features, CPI patterns and TIC parameters were analyzed and compared between different groups. Statistical analyses were performed with SPSS software and MedCalc software. The receiver operating characteristic curve was plotted.

RESULTS

In the differential diagnosis of SCLC and NSCLC, color parametric imaging indicated great performance. NSCLC exhibited a centripetal enhancement pattern more frequently (72.7%), while SCLC exhibited an eccentric enhancement pattern more frequently (92.9%) (p < 0.001). In the differential diagnosis of adenocarcinoma and squamous cell carcinoma, logistic regression analysis revealed that patient age of onset ≤60 y, difference in arrival time between lung and tumor ≤3.8 s, drop time of the time-intensity curve >23.2 s and absence of internal necrosis on CEUS were independent predictors for adenocarcinoma (area under the curve = 0.861).

CONCLUSION

In our study, multimodal contrast-enhanced ultrasound provided useful information in the differential diagnosis between small cell lung cancer and non-small cell lung cancer, especially between adenocarcinoma and squamous cell carcinoma.

Evaluation of dual-energy and perfusion CT parameters for diagnosing solitary pulmonary nodules

Background

To evaluate the correlation and accuracy of dual‐energy CT (DECT) (70/Sn150) and low‐dose volume perfusion CT (VPCT) parameters for the diagnosis of solitary pulmonary nodules (SPN).

Methods

A total of 15 patients with benign SPN (mean age 56 ± 7 years) and 34 patients with malignant SPN and clinical indication for surgery (mean age 58 ± 6 years) were enrolled from July 2017 to September 2019 at a single institution. All the patients underwent low‐dose VPCT with a scan volume of 114 mm on the z‐axis and a venous phase enhancement DECT (70/150 Sn) scan just before surgery on the same day. All CT findings were studied in comparison with the pathological results after surgery. Perfusion and dual‐energy CT parameters such as blood flow (BF), blood volume (BV), mean transit time (MTT), flow extraction product (FED), pulmonary nodule enhancement peak (PPnod) and iodine concentration (IC) were evaluated as well as t‐test, chi‐square test, Pearson correlation analysis, and ROC curve analysis to determine the significance of study parameters.

Results

The effective radiation dosage of the VPCT and DECT scans were 4.67 ± 0.26 mSv and 0.32 ± 0.10 mSv, respectively. Significant correlations were found between iodine concentration from DECT and VPCT parameters (r = 0.376–0.533, p < 0.05). The sensitivity and specificity of IC to differentiate the SPN were 86.67% and 72.73%, which was slightly lower than that of BV (94.44%, 73.33%), FED (88.89%, 80.00%) and PPnod (94.44%, 80.00%).

Conclusions

VPCT scans have low radiation dosage achieved by shortening the z‐axis scan range for assessment of SPN. IC from DECT is significantly correlated with VPCT parameters, and VPCT parameters have better diagnostic performance for SPN than DECT parameters.

Radioimmunoimaging of 125I-labeled anti-CD93 monoclonal antibodies in a xenograft model of non-small cell lung cancer

Lung cancer, especially non-small cell lung cancer (NSCLC), is the most common malignant tumor associated with poor prognosis. Angiogenesis plays a vital role in NSCLC, and could be used in tumor staging and therapy evaluation. CD93 (C1q receptor) is reportedly a key regulator of tumor angiogenesis. In the present study, the efficacy and specificity of a ¹²⁵I-labeled CD93-specific monoclonal antibody (¹²⁵I-anti-CD93 mAb) in detecting NSCLC xenografts were analyzed, and the association between CD93 expression and ¹²⁵I-anti-CD93 mAb uptake by tumors was evaluated. The targeting ability of ¹²⁵I-anti-CD93 mAb enabled its rapid, continuous and highly specific accumulation in CD93-expressing tumors in vivo. These results revealed the potential applicability of ¹²⁵I-anti-CD93 mAb for non-invasive imaging diagnosis of CD93-positive NSCLC.

Clinical diagnostic value of spiral CT in invasive pulmonary fungal infection

This study explored the diagnostic value of computed tomography (CT) in pulmonary fungal infection to provide a theoretical basis for the clinical diagnosis of pulmonary fungal infections. The clinical data of 82 suspected invasive fungal infection (IFI) patients admitted to the Department of Critical Care Medicine of The Affiliated Hospital of Qingdao University from January 2016 to May 2018 were retrospectively analyzed, and 64 of them were diagnosed with IFI by pathology and sputum culture. The CT results of the 82 patients were compared with the X-ray results in order to analyze the diagnostic value of CT imaging. Taking pathological diagnosis as the gold standard, the number of true-negative, true-positive, false-negative and false-positive results in X-ray diagnosis were 13, 43, 21 and 5, respectively, while those in CT diagnosis were 11, 59, 5 and 7, respectively. The sensitivity, specificity, accuracy, positive coincidence rate, negative coincidence rate, misdiagnosis rate and missed diagnosis rate of CT in IFI were 92.18, 61.11, 85.37, 89.39, 68.75, 38.89 and 7.81%, respectively, while those of X-ray in IFI were 67.19, 72.22, 68.29, 89.58, 38.24, 27.78 and 32.81%, respectively. The sensitivity, accuracy and negative coincidence rate of CT in the diagnosis of IFI were significantly higher than those of X-ray (P<0.05), with a sensitivity of 92.18%, which indicates that CT has a higher diagnostic value in IFI. The results of CT combined with the basic condition of the patients can be used to initially diagnose pulmonary fungal infections, which is of high diagnostic value and can improve clinical treatment.

CT Perfusion in Patients with Lung Cancer: Squamous Cell Carcinoma and Adenocarcinoma Show a Different Blood Flow

Objectives

To characterize tumour baseline blood flow (BF) in two lung cancer subtypes, adenocarcinoma (AC) and squamous cell carcinoma (SCC), also investigating those “borderline” cases whose perfusion value is closer to the group mean of the other histotype.

Materials and Methods

26 patients (age range 36-81 years) with primary Non-Small Cell Lung Cancer (NSCLC), subdivided into 19 AC and 7 SCC, were enrolled in this study and underwent a CT perfusion, at diagnosis. BF values were computed according to the maximum-slope method and unreliable values (e.g., arising from artefacts or vessels) were automatically removed. The one-tail Welch's t-test (p-value <0.05) was employed for statistical assessment.

Results

At diagnosis, mean BF values (in [mL/min/100g]) of AC group [(83.5 ± 29.4)] are significantly greater than those of SCC subtype [(57.0 ± 27.2)] (p-value = 0.02). However, two central SCCs undergoing artefacts from vena cava and pulmonary artery have an artificially increased mean BF.

Conclusions

The different hemodynamic behaviour of AC and SCC should be considered as a biomarker supporting treatment planning to select the patients, mainly with AC, that would most benefit from antiangiogenic therapies. The significance of results was achieved by automatically detecting and excluding artefactual BF values.

Evaluation of a multi-slice spiral computed tomography perfusion for the prediction of the recurrence of gastric cancer

AIM

The study aimed to elucidate the value of multislice spiral computed tomography (MSCT) perfusion for the early prediction of gastric cancer (GC) recurrence.

METHODS

MSCT perfusion scans were performed to obtain values pertaining to blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface (PS). Logistic regression analysis was employed to evaluate the risk factors of postoperative recurrence in GC.

RESULTS

The maximum diameter of GC has a positive relationship with PS. The maximum enhancement of GC was positively correlated with BF, blood volume and PS. PS, BF, vascular thrombus and Tumor, Node, Metastasis staging were found to be significant risk factors in relation to the recurrence of GC (p = 0.006, p = 0.002, p < 0.001).

CONCLUSION

MSCT perfusion is strongly correlated with postoperative recurrence of GC, and PS and BF values, vascular thrombus and Tumor, Node, Metastasis staging were discovered as being prominent factors influencing the recurrence of GC.

CDK8 regulates the angiogenesis of pancreatic cancer cells in part via the CDK8-β-catenin-KLF2 signal axis

BACKGROUND

CDK8 is associated with the transcriptional Mediator complex and has been shown to regulate several transcription factors implicated in cancer. As a pancreatic cancer oncogene, the role of CDK8 in cancer angiogenesis remains unclear. Here, we investigated the contribution of CDK8 in pancreatic cancer angiogenesis and examined the underlying molecular mechanisms.

METHODS

CDK8 expression was evaluated via immunohistochemistry, western blotting, and qRT-PCR in relation to the clinicopathological characteristics of pancreatic cancer patients. The effects of silencing or overexpressing CDK8 on cancer angiogenesis were assessed in vitro by western blotting assays in pancreatic cancer cell lines and in vivo with nude mice xenograft models.

RESULTS

Compared with adjacent normal tissues, pancreatic cancer tissues showed upregulation of CDK8 expression, which was inversely correlated with T grade, liver metastasis, size, lymph node metastasis and poor survival. CDK8 overexpression promoted angiogenesis in pancreatic cancer via activation of the CDK8-β-catenin-KLF2 signaling axis, as demonstrated by the upregulation and downregulation of signals representing the rate-limiting steps in angiogenesis. Silencing CDK8 inhibited angiogenesis in pancreatic cancer in vitro. Additionally, these results were confirmed in nude mice xenograft models in vivo.

CONCLUSIONS

CDK8 promotes angiogenesis in pancreatic cancer via activation of the CDK8-β-catenin-KLF2 signaling axis, thus providing valid targets for the treatment of pancreatic cancer.

ROI for outlining an entire tumor is a reliable approach for quantification of lung cancer tumor vascular parameters using CT perfusion

OBJECTIVE

To investigate the effect of position and size of tumor region of interest (ROI) on the estimation of lung cancer vascular parameters using 256-slice computed tomography (CT) perfusion.

METHODS

After institutional review board approval and written informed consent, 16 men and 11 women with lung cancer were enrolled in this CT perfusion study. Perfusion, blood volume, and peak enhancement were determined for 60 or 120 mm(2) circular ROIs placed at the edge, center, and around (outlining) the visible tumor. Average values were obtained by performing ROI analysis twice by the same observers without any procedural changes.

RESULTS

Perfusion, blood volume, and peak enhancement measurements were substantially higher at the edge than at the center for both 60 and 120 mm(2) ROIs (all P<0.05). Measurements varied substantially depending on the ROI size. Perfusion, blood volume, and peak enhancement for the ROIs outlining tumor were intermediate between those at the tumor edge and center. There were significant correlations between median values and interquartile ranges as follows; perfusion (12.51 [7.91-28.10] mL⋅min(-1)⋅100 mL(-1)), blood volume (29.31 [21.82-37.65] mL⋅100 g(-1)), peak enhancement (12.93 [2.42-22.50]) for the ROIs outlining the tumor, and microvascular density ([19.43±8.78] vessels/0.74 mm(2)), respectively (r values were 0.732, 0.590, and 0.544 respectively, all P<0.05).

CONCLUSION

Spatial and size selection of ROI significantly affects CT perfusion analysis. ROI outlining of entire tumor provides efficient and reliable measurements for clinical assessment of lung cancer using CT perfusion.

Uncertainty analysis of quantitative imaging features extracted from contrast-enhanced CT in lung tumors

PURPOSE

To assess the uncertainty of quantitative imaging features extracted from contrast-enhanced computed tomography (CT) scans of lung cancer patients in terms of the dependency on the time after contrast injection and the feature reproducibility between scans.

METHODS

Eight patients underwent contrast-enhanced CT scans of lung tumors on two sessions 2-7 days apart. Each session included 6 CT scans of the same anatomy taken every 15s, starting 50s after contrast injection. Image features based on intensity histogram, co-occurrence matrix, neighborhood gray-tone difference matrix, run-length matrix, and geometric shape were extracted from the tumor for each scan. Spearman's correlation was used to examine the dependency of features on the time after contrast injection, with values over 0.50 considered time-dependent. Concordance correlation coefficients were calculated to examine the reproducibility of each feature between times of scans after contrast injection and between scanning sessions, with values greater than 0.90 considered reproducible.

RESULTS

The features were found to have little dependency on the time between the contrast injection and the CT scan. Most features were reproducible between times of scans after contrast injection and between scanning sessions. Some features were more reproducible when they were extracted from a CT scan performed at a longer time after contrast injection.

CONCLUSION

The quantitative imaging features tested here are mostly reproducible and show little dependency on the time after contrast injection.

Effect of pre-enhancement set point on computed tomographic perfusion values in normal liver and metastases to the liver from neuroendocrine tumors

OBJECTIVE

The objective of this study was to assess the effects of pre-enhancement set point (T1) positioning on computed tomographic perfusion (CTp) parameter values.

METHODS

The CTp data from 16 patients with neuroendocrine liver metastases were analyzed with distributed parameter modeling to yield tissue blood flow (BF), blood volume, mean transit time, permeability, and hepatic arterial fraction for tumor and normal liver, with displacements in T1 of ±0.5, ±1.0, ±2.0 seconds, relative to the reference standard. A linear mixed-effects model was used to assess the displacement effects.

RESULTS

Effects on the CTp parameter values were variable: BF was not significantly affected, but T1 positions of ≥+1.0 second and -2.0 seconds or longer significantly affected the other CTp parameters (P ≤ 0.004). Mean differences in the CTp parameter values versus the reference standard for BF, blood volume, mean transit time, permeability, and hepatic arterial fraction ranged from -5.0% to 5.2%, -12.7% to 8.9%, -12.5% to 8.1%, -5.3% to 5.7%, and -12.9% to 26.0%, respectively.

CONCLUSIONS

CTp parameter values can be significantly affected by T1 positioning.

Metastases to the liver from neuroendocrine tumors: effect of duration of scan acquisition on CT perfusion values

PURPOSE

To assess the effects of acquisition duration on computed tomographic (CT) perfusion parameter values in neuroendocrine liver metastases and normal liver tissue.

MATERIALS AND METHODS

This retrospective study was institutional review board approved, with waiver of informed consent. CT perfusion studies in 16 patients (median age, 57.5 years; range, 42.0-69.7 years), including six men (median, 54.1 years; range, 42.0-69.7), and 10 women (median, 59.3 years; range 43.6-66.3), with neuroendocrine liver metastases were analyzed by means of distributed parametric modeling to determine tissue blood flow, blood volume, mean transit time, permeability, and hepatic arterial fraction for tumors and normal liver tissue. Analyses were undertaken with acquisition time of 12-590 seconds. Nonparameteric regression analyses were used to evaluate the functional relationships between CT perfusion parameters and acquisition duration. Evidence for time invariance was evaluated for each parameter at multiple time points by inferring the fitted derivative to assess its proximity to zero as a function of acquisition time by using equivalence tests with three levels of confidence (20%, 70%, and 90%).

RESULTS

CT perfusion parameter values varied, approaching stable values with increasing acquisition duration. Acquisition duration greater than 160 seconds was required to obtain at least low confidence stability in any of the CT perfusion parameters. At 160 seconds of acquisition, all five CT perfusion parameters stabilized with low confidence in tumor and normal tissues, with the exception of hepatic arterial fraction in tumors. After 220 seconds of acquisition, there was stabilization with moderate confidence for blood flow, blood volume, and hepatic arterial fraction in tumors and normal tissue, and for mean transit time in tumors; however, permeability values did not satisfy the moderate stabilization criteria in both tumors and normal tissue until 360 seconds of acquisition. Blood flow, mean transit time, permeability, and hepatic arterial fraction were significantly different between tumor and normal tissue at 360 seconds (P < .001).

CONCLUSION

CT perfusion parameter values are affected by acquisition duration and approach progressively stable values with increasing acquisition times. Online supplemental material is available for this article.

Effect of duration of scan acquisition on CT perfusion parameter values in primary and metastatic tumors in the lung

OBJECTIVES

To assess the effect of acquisition duration (T(acq)) and pre-enhancement set points (T₁) on computer tomography perfusion (CT(p)) parameter values in primary and metastatic tumors in the lung.

MATERIALS AND METHODS

24 lung CT(p) datasets (10 primary; 14 metastatic), acquired using a two phase protocol spanning 125 s, in 12 patients with lung tumors, were analyzed by deconvolution modeling to yield tumor blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability (PS) values. CT(p) analyses were undertaken for the reference dataset (i.e., T₁=t₀) with varying T(acq) from 12 to 125 s. This was repeated for shifts in T₁ (±0.5 s, ±1.0 s, ±2.0 s relative to the reference at t₀). Resultant CTp values were plotted against T(acq); values at 30 s, 50 s, 65 s and 125 s were compared using linear mixed model.

RESULTS

All CT(p) parameter values were noticeably influenced by T(acq), with generally less marked changes beyond 50 s, and with no difference in behavior between primary and secondary tumors. Apart from BV, which attained a plateau at approximately 50s, the other three CT(p) parameters did not reach steady-state values within the available 125 s of data, with values at 30 s, 50 s and 65 s significantly different from 125 s (p<0.004). Shifts in T₁ also affected the CT(p) parameters values, with positive shifts having greater impact on CT(p) values than negative shifts.

CONCLUSION

CT(p) parameter values derived from deconvolution modeling can be markedly affected by T(acq), and pre-enhancement set-points. 50 s acquisition may be adequate for BV, but longer than 125 s is probably required for reliable characterization of the other three CT(p) parameters.

An evaluation of the feasibility of assessment of volume perfusion for the whole lung by 128-slice spiral CT

BACKGROUND

Lung perfusion based on dynamic scanning cannot provide a quantitative assessment of the whole lung because of the limited coverage of the current computed tomography (CT) detector designs.

PURPOSE

To evaluate the feasibility of dynamic volume perfusion CT (VPCT) of the whole lung using a 128-slice CT for the quantitative assessment and visualization of pulmonary perfusion.

MATERIAL AND METHODS

Imaging was performed in a control group of 17 subjects who had no signs of disturbance of pulmonary function or diffuse lung disease, and 15 patients (five patients with acute pulmonary embolism and 10 with emphysema) who constituted the abnormal lung group. Dynamic VPCT was performed in all subjects, and pulmonary blood flow (PBF), pulmonary blood volume (PBV), and mean transit time (MTT) were calculated from dynamic contrast images with a coverage of 20.7 cm. Regional and volumetric PBF, PBV, and MTT were statistically evaluated and comparisons were made between the normal and abnormal lung groups.

RESULTS

Regional PBF (94.2 ± 36.5, 161.8 ± 29.6, 185.7 ± 38.1 and 125.5 ± 46.1, 161.9 ± 31.4, 169.3 ± 51.7), PBV (6.7 ± 2.8, 10.9 ± 3.0, 12.9 ± 4.5 and 9.9 ± 4.6, 10.3 ± 2.9, 11.9 ± 4.5), and MTT (5.8 ± 2.4, 4.5 ± 1.3, 4.7 ± 2.1 and 5.6 ± 2.3, 4.3 ± 1.5, 4.9 ± 1.5) demonstrated significant differences in the gravitational and isogravitational directions in the normal lung group (P < 0.05). The PBF (154.2 ± 30.6 vs. 94.9 ± 15.9) and PBV (11.1 ± 4.0 vs. 6.6 ± 1.7) by dynamic VPCT showed significant differences between normal and abnormal lungs (P < 0.05), notwithstanding the four large lungs that had coverage > 20.7 cm.

CONCLUSION

Dynamic VPCT of the whole lung is feasible for the quantitative assessment of pulmonary perfusion by 128-slice CT, and may in future permit the evaluation of both morphological and functional features of the whole lung in a single examination.

The Use of CT Perfusion to Determine Microvessel Density in Lung Cancer: Comparison with FDG-PET and Pathology

OBJECTIVE

To investigate the validity of CT perfusion in assessing angiogenic activity of lung cancer.

METHODS

Fifty-six patients with lung cancer scheduled for elective surgical resection received 16-slice helical CT perfusion imaging. Time-density curve (TDC), blood flow (BF), blood volume (BV), mean transmit time (MTT) and permeability surface area product (PS) were calculated. 18F-deoxyglucose-positron emission tomography (FGD-PET) was carried out in 14 out of the 56 patients to calculate standardized uptake values (SUVs). Tumor microvessel density (MVD) was examined using CD34 immunohistochemical staining of the resected tumor tissue. Pearson's correlation analysis was used to evaluate potential correlation between CT perfusion parameters and MVD or SUV.

RESULTS

Average time to peak height (TPH) of the TDCs (including two types of TDC) was 24.38±5.69 seconds. Average BF, BV, MTT and PS were 93.42±53.45 ml/100g/min,93.42±53.45 ml/100g,6.83±4.51 s and 31.92±18.73 ml/100g/min, respectively. Average MVD was 62.04±29.06/HPF. The mean SUV was 6.33±3.26. BF was positively correlated with MVD (r=0.620,P<0.01) and SUV (r=0.891, P<0.01). PS was also positively correlated with SUV (r=0.720, P<0.05). A positive correlation was also observed between tumor MVD and SUV (r=0.915, P<0.01).

CONCLUSIONS

CT perfusion imaging is a reliable tool to evaluate the tumor neovascularity of lung cancer.

Optimization of the scanning technique and diagnosis of pulmonary nodules with first-pass 64-detector-row perfusion VCT

OBJECTIVE

The aims of this study were to optimize the scanning technique of first-pass 64-detector-row perfusion volume computed tomography imaging, to evaluate the effectiveness and stability of this scan protocol, and lastly to evaluate the differential diagnosis ability of perfusion imaging in solitary pulmonary nodules (SPNs).

METHODS

A total of 144 patients with SPNs underwent perfusion scan with 64-slice spiral CT scanner. The CT perfusion imaging was analyzed for time-density curve, perfusion parametric maps, and the respective perfusion parameters. We then analyzed the main factors concerning the imaging quality and evaluated the effectiveness of scan protocol by determining the receiver operating characteristic (ROC) curve, diagnostic efficacy, and odds ratio as well as the stability of scan protocol by consistency analysis. Immunohistochemical findings of microvessel density measurement and vascular endothelial growth factor expression were evaluated.

RESULTS

The total sensitivity, specificity, accuracy, positive predictive value, negative predictive value, likelihood ratio, and the area under ROC curve during 5-45-s scan period were 78.95%, 82.4%, 80.6%, 83.3%, 77.8%, 4.620, 0.280, and 0.840, respectively, and Kappa value was 0.894. The diagnostic efficacy of CT pulmonary perfusion was significantly higher than during 0-40-s scan period. The parameter values in different nodules were different.

CONCLUSION

The optimized 5-45-s scan period of CT pulmonary perfusion imaging is effective in pathologic diagnosis and has good stability, worthy of being popularized. Lung perfusion CT could be a promising and feasible method for differentiation of SPNs.

Effect of scan time on perfusion and flow extraction product (K-trans) measurements in lung cancer using low-dose volume perfusion CT (VPCT)

RATIONALE AND OBJECTIVES

To assess the effect of measurement time on blood flow (BF), blood volume (BV), and k-trans-values (flow extraction product) in patients undergoing volume perfusion computed tomography (VPCT) for lung cancer.

MATERIALS AND METHODS

This prospective study was approved by our local Research Ethics Committee and informed consent was obtained in all patients. Between December 2009 and December 2010, 75 VPCT scans were obtained in 54 consecutive patients (15 women, 39 men) with histologically confirmed lung cancer. A 64-second VPCT of the tumor (80 kV, 60 mAs) using 128 × 0.6-mm collimation, 6.9-cm z-axis coverage and a total of 26 volume measurements, was performed. BF, BV, and K(trans) were determined. Data evaluation was performed for different measurement times (64 seconds, 45 seconds, 39 seconds, and 36 seconds) by removing the last two, four, and five scans and repeating the analysis. A one-way repeated-measures analysis of variance was used to test for effects of measurement time on BF, BV, and k-trans and unpaired/paired Student t-tests were applied for comparisons within/between groups, respectively.

RESULTS

No effect of measurement time on BF values was noted (P > .05), whereas a significant decrease of BV values (at 39 seconds: 71% ± 2% of 64-second values) and a significant increase of k-trans-values (at 39 seconds: 146% ± 8% of 64-second values) were observed with progressively shortened measurement time (P < .05, respectively). Additionally, with reduced measurement time, the increase in k-trans-values was significantly more pronounced in those patient groups with higher BV (at 39 seconds: 171% ± 15% versus 120% ± 3% of 64-second measurements), and those with lower k-trans (at 39 seconds: 167% ± 16% versus 126% ± 4% of 64-second measurements) (P < .05, respectively).

CONCLUSION

Whereas estimation of BF in lung cancer was independent from VPCT measurement time within the chosen ranges, approximation of both BV and k-trans was affected by measurement duration. A fixed measurement time of 40 seconds is recommended.

Intraobserver and interobserver agreement of volume perfusion CT (VPCT) measurements in patients with lung lesions

OBJECTIVES

To evaluate intraobserver and interobserver agreement of manually encompassed lung lesions for perfusion measurements using volume-perfusion computed tomography (VPCT).

MATERIALS AND METHODS

Institutional review board approval and informed consent were obtained. HIPAA guidelines were followed. A 65-s dynamic study was acquired with scan parameters 80 kV, 60 mAs (80 mAs for patients ≥ 70 kg), 128 × 0.6mm collimation. Blood flow (BF), blood volume (BV) and K(trans) parameters were determined by syngo volume perfusion CT body with 88 lesions analyzed retrospectively.

RESULTS

Within-subject coefficients of variation for intraobserver agreement (range 6.59-12.82%) were superior to those for interobserver agreement (range 21.75-38.30%). Size-dependent analysis revealed lower agreements for lesions <4 cm as compared to larger lesions. Additionally, agreements of the upper, middle and lower lung zones were different.

CONCLUSIONS

Intraobserver agreement was substantial for VPCT lung cancer perfusion measurements encouraging the use for tumor characterization and therapy response monitoring. Interobserver agreement is limited and unexperienced readers should be trained before using this new method.

Role of immature microvessels in assessing the relationship between CT perfusion characteristics and differentiation grade in lung cancer

BACKGROUND AND AIMS

We undertook this study to investigate the association between CT perfusion characteristics and differentiation grade in lung cancer, as well as the pathological basis of this association.

METHODS

Seventy three patients received CT perfusion scan and pathological biopsy, and 30 of them were available for comparison. In these 30 patients, the region detected with pathological biopsy was consistent with the region of interest of CT perfusion. We compared the CT perfusion parameters [blood volume (BV), blood flow (BF), and peak enhancement intensity (PEI)] of these patients with their differentiation grade of lung cancer and microvessel count, which includes microvessel density (MVD) and maturity.

RESULTS

The lower the grade of differentiation of the nodules, the more drastically perfusion parameters decreased. BF was best correlated with differentiation grade (r = -0.845, p = 0.000), compared to BV and PEI (r = -0.674, -0.438, p = 0.000, 0.015, respectively). Poorly differentiated lung cancer showed significantly higher density of immature microvessels than that of highly differentiated lung cancer (p = 0.001). There was a correlation between the differentiation grade and the density of immature microvessels (r = 0.669, p = 0.000), but there was no significant correlation with MVD and the density of mature microvessel (r = 0.345, 0.269, p = 0.062, 0.150, respectively). The density of immature microvessels still increased with declining BF value in the nodules when the grade of differentiation of lung cancer was under control (r = -0.748, p = 0.000).

CONCLUSIONS

CT perfusion characteristics are helpful to differentiate lung cancer differentiation, pathologically basing on the density of immature microvessels rather than MVD.

Angiogenesis of renal cell carcinoma: perfusion CT findings

OBJECTIVE

To observe the perfusion CT findings of renal cell carcinoma (RCC) and prospectively correlate perfusion CT parameters with tumor MVD and VEGF expression.

METHODS

Dynamic contrast-enhanced multislice spiral CT was performed prospectively in 73 cases with histologically proven RCC (65 clear cell, 3 papillary, and 5 chromophobe). Blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface-area product (PS) of RCC and normal renal cortex were measured, respectively. The tumor MVD count and VEGF expression level were determined by immunohistochemistry with specific monoclonal antibodies.

RESULTS

There was significant difference between BF, BV, MTT, and PS of normal renal cortex (454.32 ± 110.90 mL/min/100 g, 23.53 ± 5.71 mL/100 g, 3.62 ± 1.38 s, 63.95 ± 18.85 mL/min/100 g) and RCC (261.96 ± 175.86 mL/min/100 g, 17.17 ± 8.34 mL/100 g, 7.08 ± 3.42 s, 25.07 ± 13.20 mL/min/100 g) (P < 0.01). BF and BV among RCC histologic subtypes were significantly different (P < 0.05), MTT and PS were not (P > 0.05). MVD (42.29 ± 21.00) of RCC is positively correlated with BF, BV, and PS (P < 0.01), not with MTT (P > 0.05). No relationship was found between the expression levels of VEGF and any perfusion CT parameter.

CONCLUSIONS

Perfusion CT is a feasible technique to assess tissue perfusion in patients with RCC. BV, BF, and PS correlate positively with MVD and may reflect angiogenesis of RCC.

Advances in imaging diagnosis of pancreatic cancer

Early diagnosis of pancreatic carcinoma is very important for effective management of the disease. The imaging techniques traditionally used for diagnosis of pancreatic carcinoma include computed tomography (CT), magnetic resonance imaging (MRI) and ultrasound imaging. In recent years, some new imaging techniques, such as Positron emission tomography (PET)-CT fusion and magnetic resonance spectroscopy (MRS), have been developed. These new imaging techniques play a crucial role in the early diagnosis of pancreatic carcinoma.

Enhancement patterns of pancreatic adenocarcinoma on conventional dynamic multi-detector row CT: correlation with angiogenesis and fibrosis

AIM

To evaluate retrospectively the correlation between enhancement patterns on dynamic computed tomography (CT) and angiogenesis and fibrosis in pancreatic adenocarcinoma.

METHODS

Twenty-three patients with pancreatic adenocarcinoma underwent dynamic CT and tumor resection. In addition to the absolute and relative enhanced value that was calculated by subtracting the attenuation value on pre-contrast from those on contrast-enhanced CT in each phase, we defined one parameter, "tumor-aorta enhancement ratio", which was calculated by dividing enhancement of pancreatic cancer by enhancement of abdominal aorta in each phase. These enhancement patterns were correlated with the level of vascular endothelial growth factor (VEGF), microvessel density (MVD), and extent of fibrosis.

RESULTS

The absolute enhanced value in the arterial phase correlated with the level of VEGF and MVD (P = 0.047, P = 0.001). The relative enhanced value in arterial phase and tumor-aorta enhancement ratio (arterial) correlated with MVD (P = 0.003, P = 0.022). Tumor-aorta enhancement ratio (arterial) correlated negatively with the extent of fibrosis (P = 0.004). The tumors with greater MVD and higher expression of VEGF tended to show high enhancement in the arterial dominant phase. On the other hand, the tumors with a larger amount of fibrosis showed a negative correlation with the grade of enhancement during the arterial phase.

CONCLUSION

Enhancement patterns on dynamic CT correlated with angiogenesis and may be modified by the extent of fibrosis.

Enhancement patterns of pancreatic adenocarcinoma on conventional dynamic multi-detector row CT: Correlation with angiogenesis and fibrosis

AIM: To evaluate retrospectively the correlation between enhancement patterns on dynamic computed tomography (CT) and angiogenesis and fibrosis in pancreatic adenocarcinoma.

METHODS: Twenty-three patients with pancreatic adenocarcinoma underwent dynamic CT and tumor resection. In addition to the absolute and relative enhanced value that was calculated by subtracting the attenuation value on pre-contrast from those on contrast-enhanced CT in each phase, we defined one parameter, “tumor-aorta enhancement ratio”, which was calculated by dividing enhancement of pancreatic cancer by enhancement of abdominal aorta in each phase. These enhancement patterns were correlated with the level of vascular endothelial growth factor (VEGF), microvessel density (MVD), and extent of fibrosis.

RESULTS: The absolute enhanced value in the arterial phase correlated with the level of VEGF and MVD (P = 0.047, P = 0.001). The relative enhanced value in arterial phase and tumor-aorta enhancement ratio (arterial) correlated with MVD (P = 0.003, P = 0.022). Tumor-aorta enhancement ratio (arterial) correlated negatively with the extent of fibrosis (P = 0.004). The tumors with greater MVD and higher expression of VEGF tended to show high enhancement in the arterial dominant phase. On the other hand, the tumors with a larger amount of fibrosis showed a negative correlation with the grade of enhancement during the arterial phase.

CONCLUSION: Enhancement patterns on dynamic CT correlated with angiogenesis and may be modified by the extent of fibrosis.

Body perfusion CT: technique, clinical applications, and advances

Perfusion CT has made tremendous progress since its inception and is gradually broadening its applications from the research realm into routine clinical care. This has been particularly noteworthy in the oncological setting, where perfusion CT is emerging as a valuable tool in tissue characterization, risk stratification and monitoring treatment effects especially assessing early response to novel targeted therapies. Recent technological advancements in CT have paved ways to overcome the initial limitations of restricted tissue coverage and radiation dose concerns. In this article, the authors review the basic principles and technique of perfusion CT and discuss its various oncologic and non-oncological clinical applications in body imaging.

[Tumor vasculature as a therapeutic target in non-small cell lung cancer]

Despite developments in conventional (chemo)radiotherapy and surgery, survival of non-small cell lung cancer (NSCLC) patients remains poor. Treatments with targeted molecular drugs offer novel therapeutic strategies. Bevacizumab, a recombinant anti-vascular endothelial growth factor (VEGF) antibody, is the antiangiogenic drug at the most advanced stage of development in the therapy of NSCLC. However, a number of questions and future challenges relating to the use of bevacizumab in NSCLC remain. Furthermore, novel agents targeting the pre-existing NSCLC vasculature (i.e. vascular disrupting agents, VDAs) or multiple tyrosine kinase inhibitors have emerged as unique drug classes delivering promising results in several preclinical and clinical studies. Herein, we review the most recent data using these novel targeted agents either alone or in combination with chemotherapy in NSCLC.

Clinical biomarkers of angiogenesis inhibition

INTRODUCTION

An expanding understanding of the importance of angiogenesis in oncology and the development of numerous angiogenesis inhibitors are driving the search for biomarkers of angiogenesis. We review currently available candidate biomarkers and surrogate markers of anti-angiogenic agent effect.

DISCUSSION

A number of invasive, minimally invasive, and non-invasive tools are described with their potential benefits and limitations. Diverse markers can evaluate tumor tissue or biological fluids, or specialized imaging modalities.

CONCLUSIONS

The inclusion of these markers into clinical trials may provide insight into appropriate dosing for desired biological effects, appropriate timing of additional therapy, prediction of individual response to an agent, insight into the interaction of chemotherapy and radiation following exposure to these agents, and perhaps most importantly, a better understanding of the complex nature of angiogenesis in human tumors. While many markers have potential for clinical use, it is not yet clear which marker or combination of markers will prove most useful.