Whole-tumour CT-perfusion of unresectable lung cancer for the monitoring of anti-angiogenetic chemotherapy effects

Dynamic contrast enhanced MRI of pulmonary adenocarcinomas for early risk stratification: higher contrast uptake associated with response and better prognosis

BACKGROUND

To explore the prognostic value of serial dynamic contrast-enhanced (DCE) MRI in patients with advanced pulmonary adenocarcinoma undergoing first-line therapy with either tyrosine-kinase inhibitors (TKI) or platinum-based chemotherapy (PBC).

METHODS

Patients underwent baseline (day 0, n = 98), and post-therapeutic DCE MRI (PBC: day + 1, n = 52); TKI: day + 7, n = 46) at 1.5T. Perfusion curves were acquired at 10, 40, and 70 s after contrast application and analysed semiquantitatively. Treatment response was evaluated at 6 weeks by CT (RECIST 1.1); progression-free survival (PFS) and overall survival  were analysed with respect to clinical and perfusion parameters. Relative uptake was defined as signal difference between contrast and non-contrast images, divided by the non-contrast signal. Predictors of survival were selected using Cox regression analysis. Median follow-up was 825 days.

RESULTS

In pre-therapeutic and early post-therapeutic MRI, treatment responders (n = 27) showed significantly higher relative contrast uptake within the tumor at 70 s after application as compared to non-responders (n = 71, p ≤ 0.02), response defined as PR by RECIST 1.1 at 6 weeks. There was no significant change of perfusion at early MRI after treatment. In multivariate regression analysis of selected parameters, the strongest association with PFS were relative uptake at 40 s in the early post-treatment MRI and pre-treatment clinical data (presence of liver metastases, ECOG performance status).

CONCLUSION

Higher contrast uptake within the tumor at pre-treatment and early post-treatment MRI was associated with treatment response and better prognosis. DCE MRI of pulmonary adenocarcinoma may provide important prognostic information.

Application of diffusion kurtosis imaging and 18F-FDG PET in evaluating the subtype, stage and proliferation status of non-small cell lung cancer

Background

Lung cancer has become one of the deadliest tumors in the world. Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, accounting for approximately 80%-85% of all lung cancer cases. This study aimed to investigate the value of diffusion kurtosis imaging (DKI), diffusion-weighted imaging (DWI) and 2-[¹⁸F]-fluoro-2-deoxy-D-glucose positron emission tomography (¹⁸F-FDG PET) in differentiating squamous cell carcinoma (SCC) and adenocarcinoma (AC) and to evaluate the correlation of each parameter with stage and proliferative status Ki-67.

Methods

Seventy-seven patients with lung lesions were prospectively scanned by hybrid 3.0-T chest ¹⁸F-FDG PET/MR. Mean kurtosis (MK), mean diffusivity (MD), apparent diffusion coefficient (ADC), maximum standard uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were measured. The independent samples t test or Mann–Whitney U test was used to compare and analyze the differences in each parameter of SCC and AC. The diagnostic efficacy was evaluated by receiver operating characteristic (ROC) curve analysis and compared with the DeLong test. A logistic regression analysis was used for the evaluation of independent predictors. Bootstrapping (1000 samples) was performed to establish a control model, and calibration curves and ROC curves were used to validate its performance. Pearson’s correlation coefficient and Spearman’s correlation coefficient were calculated for correlation analysis.

Results

The MK and ADC values of the AC group were significantly higher than those of the SCC group (all P< 0.05), and the SUVmax, MTV, and TLG values of the SCC group were significantly higher than those of the AC group (all P<0.05). There was no significant difference in the MD value between the two groups. Moreover, MK, SUVmax, TLG and MTV were independent predictors of the NSCLC subtype, and the combination of these parameters had an optimal diagnostic efficacy (AUC, 0.876; sensitivity, 86.27%; specificity, 80.77%), which was significantly better than that of MK (AUC = 0.758, z = 2.554, P = 0.011), ADC (AUC = 0.679, z = 2.322, P = 0.020), SUVmax (AUC = 0.740, z = 2.584, P = 0.010), MTV (AUC = 0.715, z = 2.530, P = 0.011) or TLG (AUC = 0.716, z = 2.799, P = 0.005). The ROC curve showed that the validation model had high accuracy in identifying AC and SCC (AUC, 0.844; 95% CI, 0.785-0.885);. The SUVmax value was weakly positively correlated with the Ki-67 index (r = 0.340, P< 0.05), the ADC and MD values were weakly negatively correlated with the Ki-67 index (r = -0.256, -0.282, P< 0.05), and the MTV and TLG values were weakly positively correlated with NSCLC stage (r = 0.342, 0.337, P< 0.05).

Conclusion

DKI, DWI and ¹⁸F-FDG PET are all effective methods for assessing the NSCLC subtype, and some parameters are correlated with stage and proliferation status.

Diagnostic and prognostic value of CT perfusion parameters in patients with advanced NSCLC after chemotherapy

OBJECTIVE

To determine the short-term prognostic value of Computed Tomography (CT) perfusion parameters in patients with advanced non-small cell lung cancer (NSCLC) after chemotherapy.

METHODS

A total of 60 patients with NSCLC who received concurrent radiotherapy and chemotherapy were enrolled. Before therapy, CT perfusion imaging was conducted to scan their local lesions. Then, the CT perfusion-associated parameters were recorded, and evaluated. According to the Response Evaluation Criteria in Solid Tumors (RECIST), 42 out of 60 patients had remission after chemotherapy. The blood flow (BF), blood volume (BV), and permeability surface (PS) of the two groups were analyzed before therapy, and factors and parameters affecting the efficacy of concurrent radiotherapy and chemotherapy were discussed.

RESULTS

After chemotherapy, patients with remission showed lower BF, BV, and PS levels in pulmonary lesions than those without remission (all P<0.05). According to the 1-year follow-up results, 33 cases survived, and 27 cases died, and the survivors showed lower BF and PS levels than the dead (both P<0.05).

CONCLUSION

Patients with lower BF and PS in CT perfusion parameters obtained better chemotherapy efficacy, so BF and PS can be adopted to predict the survival of patients.

A Pilot Study to Evaluate Early Predictive Value of Thorax Perfusion-CT in Advanced NSCLC

Simple Summary

The use of targeted drugs has brought about the development of new imaging techniques which are able to assess in vivo processes and changes in vascularization parameters can be captured as part of the antitumor response to antiangiogenic therapies. This pilot study (IMPACT trial, NCT02316327) aimed to explore the capacity of Perfusion-Computed Tomography (pCT) to detect early changes in tumor vascularization in non-small cell lung cancer (NSCLC) patients treated with an antiangiogenic-based therapy. Our results confirm the feasibility of pCT to capture early changes in tumor vasculature and suggest the potential of blood volume (BV) to early identify differential tumor responses to antiangiogenic therapy.

Abstract

Background: The role of perfusion computed tomography (pCT) in detecting changes in tumor vascularization as part of a response to antiangiogenic therapy in non-small cell lung cancer (NSCLC) remains unclear. Methods: In this prospective pilot study (IMPACT trial, NCT02316327), we aimed to determine the ability of pCT to detect early changes in blood flow (BF), blood volume (BV), and permeability (PMB), and to explore whether these changes could predict the response at day +42 in patients with advanced, treatment-naive, non-squamous NSCLC treated with cisplatin and gemcitabine plus bevacizumab. Results: All of the perfusion parameters showed a consistent decrease during the course of treatment. The BV difference between baseline and early assessment was significant (p = 0.013), whereas all perfusion parameters showed significant differences between baseline and day +42 (p = 0.003, p = 0.049, and p = 0.002, respectively). Among the 16 patients evaluable for efficacy, a significant decline in BV at day +7 from baseline was observed in tumors with no response (p = 0.0418). Conclusions: Our results confirm that pCT can capture early changes in tumor vasculature. A substantial early decline of BV from baseline might identify tumors less likely responsive to antiangiogenic-drugs.

A Single Enhanced Dual-Energy CT Scan May Distinguish Lung Squamous Cell Carcinoma From Adenocarcinoma During the Venous phase

RATIONALE AND OBJECTIVES

To investigate whether iodine quantification extracted from enhanced dual energy-computed tomography (DE-CT) is useful for distinguishing lung squamous cell carcinoma from adenocarcinoma and to evaluate whether a single scan evaluated during the venous phase (VP) can be substituted for scans evaluated during other phases.

MATERIALS AND METHODS

Sixty-two patients with lung cancer (32 squamous cell carcinomas; 30 adenocarcinomas) underwent enhanced dual-phase DE-CT scans, including an arterial phase and VP. The iodine concentration (IC), normalized iodine concentration (NIC), and slope of the curve (K) in lesions were measured during two scanning phases in two different pathological types of lung cancers. The differences in parameters (IC, NIC, and K) between these two types of lung cancers were statistically analyzed. In addition, the receiver operating characteristic curves of these parameters were performed to discriminate squamous cell carcinoma from adenocarcinoma.

RESULTS

The mean IC, NIC, and K in adenocarcinomas were all higher than those in squamous cell carcinomas during the two scanning phases. However, the differences in these parameters between the two types of cancers were significant only during the VP, not during the arterial phase. Receiver operating characteristic analysis demonstrated that the optimal thresholds of the IC, NIC, and K for discriminating squamous cell carcinoma from adenocarcinoma were 1.550, 0.227, and 1.608, respectively. In addition, the sensitivity, specificity, and area under the curve were 81.2%, 83.3%, and 0.871 for the IC; 56.2%, 93.3%, and 0.800 for the NIC; and 65.6%, 80%, and 0.720 for the K; 81.3%, 83.3%, and 0.874 for the IC + NIC; 68.8%, 93.3%, and 0.891 for the IC + NIC + K, respectively. The "IC + NIC + K" had the highest diagnostic efficiency for discriminating two types of lung cancers, but with low sensitivity. Whereas, "IC"and "IC + NIC" had the similar lower diagnostic efficiency, but with high sensitivity and specificity.

CONCLUSION

The iodine quantification parameters derived from enhanced DE-CT during the VP may be useful for distinguishing lung squamous cell carcinoma from adenocarcinoma.

Spectral CT and its specific values in the staging of patients with non-small cell lung cancer: technical possibilities and clinical impact

AIM

To investigate how spectral computed tomography (SCT) values impact the staging of non-small cell lung cancer (NSCLC) patients.

MATERIALS AND METHODS

One hundred and thirteen patients with confirmed NSCLC were included in a prospective cohort study. All patients underwent single-phase contrast-enhanced SCT (using the fast tube voltage switching technique, 80-140 kV). SCT values (iodine content [IC], spectral slope pitch, and radiodensity increase) of malignant tissue (primary and metastases) and lymph nodes (LNs) were measured. Adrenal masses were evaluated in a virtual non-contrast series (VNS). If pulmonary embolism was present, pulmonary perfusion was analysed as an additional finding.

RESULTS

Fifty-two untreated primary NSCLC lesions were evaluable. Lung adenocarcinoma had significantly higher normalised IC (NIC: 19.37) than squamous cell carcinoma (NIC: 12.03; p=0.035). Pulmonary metastases were not significantly different from benign lung nodules. A total of 126 LNs were analysed and histologically proven metastatic LNs (2.08 mg/ml) had significantly lower IC than benign LNs (2.58 mg/ml; p=0.023). Among 34 adrenal masses, VNS identified adenomas with high sensitivity (91%) and specificity (100%). In two patients, a perfusion defect due to pulmonary embolism was detected in the iodine images.

CONCLUSION

SCT may contribute to the differentiation of histological NSCLC subtypes and improve the identification of LN metastases. VNS differentiates adrenal adenoma from metastasis. In case of pulmonary embolism, iodine imaging can visualise associated pulmonary perfusion defects.

Multislice Analysis of Blood Flow Values in CT Perfusion Studies of Lung Cancer

Objectives. Tumour heterogeneity represents a key issue in CT perfusion (CTp), where all studies are usually based on global mean or median values of perfusion maps, often computed on whole tumour. We sought to determine whether, and to what extent, such global values can be representative of tumour heterogeneity, with respect to single slices, and could be used for therapy assessment. Materials and Methods. Twelve patients with one primary non-small cell lung cancer lesion were enrolled in this study, for a total amount of 26 CTp examinations and 118 slices. Mean and median blood flow (BF) values, calculated voxel-based, were computed on each slice and the whole tumour. To measure functional heterogeneity, entropy was calculated on BF values as well. Results. Most of the slices were not represented by the global BF values computed on the whole tumour. In addition, there are a number of lesions having equivalent global BF values, but they are composed of slices having very different heterogeneity distributions, that is, entropy values. Conclusions. Global mean/median BF values of the single slices separately should be considered for clinical assessment, only if interpreted through entropy computed on BF values. The numerical equivalence between global BF values of different lesions may correspond to different clinical status, thus inducing possible errors in choice of therapy when considering global values only.

From diagnosis to therapy in lung cancer: management of CT detected pulmonary nodules, a summary of the 2015 Chinese-German Lung Cancer Expert Panel

The first Chinese-German Lung Cancer Expert Panel was held in November 2015 one day after the 7th Chinese-German Lung Cancer Forum, Shanghai. The intention of the meeting was to discuss strategies for the diagnosis and treatment of lung cancer within the context of lung cancer screening. Improved risk classification criteria and novel imaging approaches for screening populations are highly required as more than half of lung cancer cases are false positive during the initial screening round if the National Lung Screening Trial (NLST) demographic criteria [≥30 pack years (PY) of cigarettes, age ≥55 years] are applied. Moreover, if the NLST criteria are applied to the Chinese population a high number of lung cancer patients are not diagnosed due to non-smoking related risk factors in China. The primary goal in the evaluation of pulmonary nodules (PN) is to determine whether they are malignant or benign. Volumetric based screening concepts such as investigated in the Dutch-Belgian randomized lung cancer screening trial (NELSON) seem to achieve higher specificity. Chest CT is the best imaging technique to identify the origin and location of the nodule since 20% of suspected PN found on chest X-ray turn out to be non-pulmonary lesions. Moreover, novel state-of-the-art CT systems can reduce the radiation dose for lung cancer screening acquisitions down to a level of 0.1 mSv with improved image quality to novel reconstruction techniques and thus reduce concerns related to chest CT as the primary screening technology. The aim of the first part of this manuscript was to summarize the current status of novel diagnostic techniques used for lung cancer screening and minimally invasive treatment techniques for progressive PNs that were discussed during the first Chinese-German Lung Cancer. This part should serve as an educational part for the readership of the techniques that were discussed during the Expert Panel. The second part summarizes the consensus recommendations that were interdisciplinary discussed by the Expert Panel.

Magnetic resonance-guided focused ultrasound for the treatment of painful bone metastases: role of apparent diffusion coefficient (ADC) and dynamic contrast enhanced (DCE) MRI in the assessment of clinical outcome

PURPOSE

To assess the correlation between functional MRI, including ADC values obtained from DWI and DCE, and clinical outcome in patients with bone metastases treated with MRgFUS.

METHODS AND MATERIALS

Twenty-three patients with symptomatic bone metastases underwent MRgFUS treatment (ExAblate 2100 system InSightec) for pain palliation. All patients underwent clinical and imaging follow-up examinations at 1, 3 and 6 months after treatment. Visual Analog Scale (VAS) score was used to evaluate treatment efficacy in terms of pain palliation while ADC maps obtained by DWI sequences, and DCE data were used for quantitative assessment of treatment response at imaging. Spearman Correlation Coefficient Test was calculated to assess the correlation between VAS, ADC and DCE data.

RESULTS

All treatments were performed successfully without adverse events. On the basis of VAS score, 16 (69.6 %) patients were classified as complete clinical responders, 6 (26.1 %) as partial responders and only one (4.3 %) was classified as a non-responder. The mean VAS score decreased from 7.09 ± 1.8 at baseline to 2.65 ± 1.36 at 1 month, 1.04 ± 1.91 at 3 months and 1.09 ± 1.99 at 6 months (p < 0.001). Baseline mean ADC value of treated lesions was 1.05 ± 0.15 mm²/s, increasing along follow-up period (1.57 ± 0.27 mm²/s 1st month; 1.49 ± 0.3 mm²/s 3rd month; 1.45 ± 0.32 mm²/s 6th month, p < 0.001). Non perfused volume (NPV) was 46.4 at 1 month, 45.2 at 3 months and 43.8 at 6 months. Spearman Coefficient demonstrated a statistically significant negative correlation between VAS and ADC values (ρ = -0.684; p = 0.03), but no significant correlation between VAS and NPV (ρ = 0.02216, p = 0.9305). Among other DCE data, Ktrans significantly changed in complete responders (3 months Ktrans = 2.14/min; -ΔKt = 52.65 % p < 0.01) and was not significantly different in partial responders (3 months Ktrans 0.042/min; ΔKt = 11.39 % p > 0.01).

CONCLUSION

In patients with painful bone metastases treated with MRgFUS, ADC and Ktrans variation observed in the ablated lesions correlate with VAS values and may play a role as objective imaging marker of treatment response.

Assessing Tumor Response to Treatment in Patients with Lung Cancer Using Dynamic Contrast-Enhanced CT

The aim of this study was to provide an overview of the literature available on dynamic contrast-enhanced computed tomography (DCE-CT) as a tool to evaluate treatment response in patients with lung cancer. This systematic review was compiled according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Only original research articles concerning treatment response in patients with lung cancer assessed with DCE-CT were included. To assess the validity of each study we implemented Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). The initial search yielded 651 publications, and 16 articles were included in this study. The articles were divided into groups of treatment. In studies where patients were treated with systemic chemotherapy with or without anti-angiogenic drugs, four out of the seven studies found a significant decrease in permeability after treatment. Four out of five studies that measured blood flow post anti-angiogenic treatments found that blood flow was significantly decreased. DCE-CT may be a useful tool in assessing treatment response in patients with lung cancer. It seems that particularly permeability and blood flow are important perfusion values for predicting treatment outcome. However, the heterogeneity in scan protocols, scan parameters, and time between scans makes it difficult to compare the included studies.

Quantitative Computed Tomography Imaging Biomarkers in the Diagnosis and Management of Lung Cancer

Tumor diameter has traditionally been used as a standard metric in terms of diagnosis and prognosis prediction of lung cancer. However, recent advances in imaging techniques and data analyses have enabled novel quantitative imaging biomarkers that can characterize disease status more comprehensively and/or predict tumor behavior more precisely. The most widely used imaging modality for lung tumor assessment is computed tomography. Therefore, we focused on computed tomography imaging biomarkers such as tumor volume and mass, ground-glass opacities, perfusion parameters, as well as texture features in this review. Herein, we first appraised the conventional 1- or 2-dimensional measurement with brief discussion on their limits and then introduced the potential imaging biomarkers with emphasis on the current understanding of their clinical usefulness with respect to the malignancy differentiation, treatment response monitoring, and patient outcome prediction.

Assessment of bronchial and pulmonary blood supply in non-small cell lung cancer subtypes using computed tomography perfusion

OBJECTIVES

The aim of this study was to investigate the dual blood supply of non-small cell lung cancer (NSCLC) and its association with tumor subtype, size, and stage, using computed tomography perfusion (CTP).

MATERIALS AND METHODS

A total of 54 patients (median age, 65 years; range, 42-79 years; 15 women, 39 men) with suspected lung cancer underwent a CTP scan of the lung tumor. Pulmonary and bronchial vasculature regions of interest were used to calculate independently CTP parameters (blood flow [BF], blood volume [BV], and mean transit time [MTT]) of the tumor tissue. The mean and maximum pulmonary and bronchial perfusion indexes (PImean and PImax) were calculated. The tumoral volume and the largest tumoral diameter were assessed. Differences in CTP parameters and indexes among NSCLC subtypes, tumor stages and tumor dimensions were analyzed using non-parametric tests.

RESULTS

According to biopsy, 37 patients had NSCLC (22 adenocarcinomas [ACs], 8 squamous cell carcinomas [SCCs], 7 large-cell carcinomas [LCC]). The mean bronchial BF/pulmonary BF, bronchial BV/pulmonary BV, and bronchial MTT/pulmonary MTT was 41.2 ± 30.0/36.9 ± 24.2 mL/100 mL/min, 11.4 ± 9.7/10.4 ± 9.4 mL/100 mL, and 11.4 ± 4.3/14.9 ± 4.4 seconds, respectively. In general, higher bronchial BF than pulmonary BF was observed in NSCLC (P = 0.014). Using a tumoral volume cutoff of 3.5 cm, a significant difference in pulmonary PImax was found (P = 0.028). There was a significantly higher mean pulmonary BF in LCCs and SCCs compared with ACs (P = 0.018 and P = 0.044, respectively), whereas the mean bronchial BF was only significantly higher in LCCs compared with ACs (P = 0.024). Correspondingly, the PImax was significantly higher in LCCs and SCCs than in ACs (P = 0.001 for both). Differences between bronchial and pulmonary PImean and PImax among T stages and Union Internationale Contre le Cancer stages were not statistically significant (P values ranging from 0.691 to 0.753).

CONCLUSIONS

The known dual blood supply of NSCLC, which depends on tumor size and histological subtype, is reflected in CTP parameters, with parameters depending both on tumor size and histological subtype. This has to be accounted for when analyzing NSCLC with CTP.

CT perfusion imaging in response assessment of pulmonary metastases undergoing stereotactic ablative radiotherapy

INTRODUCTION

Stereotactic ablative body radiotherapy (SABR) is an emerging treatment technique for pulmonary metastases in which conventional Response Evaluation Criteria in Solid Tumours (RECIST) may be inadequate. This study aims to assess the utility of CT perfusion imaging in response assessment of pulmonary metastases after SABR.

METHODS

In this ethics board-approved prospective study, 11 patients underwent a 26-Gy single fraction of SABR to pulmonary metastases. CT perfusion imaging occurred prior to and at 14 and 70 days post-SABR. Blood flow (mL/100 mL/min), blood volume (mL/100 mL), time to peak (seconds) and surface permeability (mL/100 mL/min), perfusion parameters of pulmonary metastases undergoing SABR, were independently assessed by two radiologists. Inter-observer variability was analysed. CT perfusion results were analysed for early response assessment comparing day 14 with baseline scans and for late response by comparing day 70 with baseline scans. The largest diameter of the pulmonary metastases undergoing SABR was recorded.

RESULTS

Ten patients completed all three scans and one patient had baseline and early response assessment CT perfusion scans only. There was strong level of inter-observer agreement of CT perfusion interpretation with a median intraclass coefficient of 0.87 (range 0.20-0.98). Changes in all four perfusion parameters and tumour sizes were not statistically significant.

CONCLUSION

CT perfusion imaging of pulmonary metastases is a highly reproducible imaging technique that may provide additional response assessment information above that of conventional RECIST, and it warrants further study in a larger cohort of patients undergoing SABR.

[Recommendations for radiological diagnosis and assessment of treatment response in lung cancer: a national consensus statement by the Spanish Society of Medical Radiology and the Spanish Society of Medical Oncology]

The last decade has seen substantial progress in the diagnostic and therapeutic approach to lung cancer, thus meaning that its prognosis has improved. The Spanish Society of Medical Radiology (SERAM) and the Spanish Society of Medical Oncology (SEOM) have therefore produced a national consensus statement in order to make recommendations for radiological diagnosis and assessment of treatment response in patients with lung cancer. This expert group recommends multi-detector computed tomography (MDCT) as the technique of choice for investigating this disease. The radiology report should include a full assessment by the TNM staging system. Lastly, when the patient is on immunotherapy, response evaluation should employ not only Response Evaluation Criteria in Solid Tumours (RECIST 1.1) but also Immune-Related Response Criteria (irRC).

Recommendations for radiological diagnosis and assessment of treatment response in lung cancer: a national consensus statement by the Spanish Society of Medical Radiology and the Spanish Society of Medical Oncology

The last decade has seen substantial progress in the diagnostic and therapeutic approach to lung cancer, thus meaning that its prognosis has improved. The Spanish Society of Medical Radiology and the Spanish Society of Medical Oncology have therefore produced a national consensus statement to make recommendations for radiological diagnosis and assessment of treatment response in patients with lung cancer. This expert group recommends multi-detector computed tomography as the technique of choice for investigating this disease. The radiology report should include a full assessment by the TNM staging system. Lastly, when the patient is on immunotherapy, response evaluation should employ not only response evaluation criteria in solid tumours, but also immune-related response criteria.

Perfusion CT is a valuable diagnostic method for prostate cancer: a prospective study of 94 patients

Purpose

The aim of this study is to assess the usefulness of perfusion computer tomography (pCT) in prostate cancer (PCa) diagnostics.

Materials and Methods

94 patients with biopsy-proven PCa were enrolled in the study. Dynamic pCT of the prostate gland was performed for 50 seconds after an intravenous injection of contrast medium. Blood flow (BF), blood volume (BV), mean transit time (MTT) and permeability surface area product (PS) were computed in the suspected PCa area and in normal prostatic tissue.

Results

PCa was visible in pCT in 90 of the 94 examined patients as a focal peripheral CT enhancement. When PCa was located in the peripheral zone (PZ), it was visible on perfusion maps, mostly showing an early peak followed by wash-out. The average values of all perfusion parameters were higher for tumour than for normal prostate tissue (p < 0.000). BV and BF were dependent on tumour grade expressed by the Gleason score (GS). All PCa cases were divided into groups, according to histological grade, as low (GS ≤ 6), medium (GS = 7), and high (GS > 7). In high-grade PCa, the mean BF value was significantly higher (p = 0.001) than the mean value of BF low- and medium-grade PCa (p = 0.011). Similar results were obtained regarding the mean values of BV; the more aggressive the cancer grade, the higher the mean BV value (p = 0.04).

Conclusion

CT quantitative perfusion imaging allows PCa to be distinguished from normal prostate tissue. The highest values for BF and BV were observed in the most aggressive PCa grade.

Lung cancer imaging

Lung cancer remains the leading cause of cancer-related deaths in the US. Imaging plays an important role in the diagnosis, staging, and follow-up evaluation of patients with lung cancer. With recent advances in technology, it is important to update and standardize the radiological practices in lung cancer evaluation. In this article, the authors review the main clinical applications of different imaging modalities and the most common radiological presentations of lung cancer.

Computed tomography (CT) perfusion as an early predictive marker for treatment response to neoadjuvant chemotherapy in gastroesophageal junction cancer and gastric cancer--a prospective study

Objectives

To evaluate whether early reductions in CT perfusion parameters predict response to pre-operative chemotherapy prior to surgery for gastroesophageal junction (GEJ) and gastric cancer.

Materials and Methods

Twenty-eight patients with adenocarcinoma of the gastro-esophageal junction (GEJ) and stomach were included. Patients received three series of chemotherapy before surgery, each consisting of a 3-week cycle of intravenous epirubicin, cisplatin or oxaliplatin, concomitant with capecitabine peroral. The patients were evaluated with a CT perfusion scan prior to, after the first series of, and after three series of chemotherapy. The CT perfusion scans were performed using a 320-detector row scanner. Tumour volume and perfusion parameters (arterial flow, blood volume and permeability) were computed on a dedicated workstation with a consensus between two radiologists. Response to chemotherapy was evaluated by two measures. Clinical response was defined as a tumour size reduction of more than 50%. Histological response was evaluated based on residual tumour cells in the surgical specimen using the standardized Mandard Score 1 to 5, in which values of 1 and 2 were classified as responders, and 3 to 5 were classified as nonresponders.

Results

A decrease in tumour permeability after one series of chemotherapy was positively correlated with clinical response after three series of chemotherapy. Significant changes in permeability and tumour volume were apparent after three series of chemotherapy in both clinical and histological responders. A cut-off value of more than 25% reduction in tumour permeability yielded a sensitivity of 69% and a specificity of 58% for predicting clinical response.

Conclusion

Early decrease in permeability is correlated with the likelihood of clinical response to pre-operative chemotherapy in GEJ and gastric cancer. As a single diagnostic test, CT Perfusion only has moderate sensitivity and specificity in response assessment of pre-operative chemotherapy making it insufficient for clinical decision purposes.