Computed tomography perfusion imaging as a potential imaging biomarker of colorectal cancer.

Neovascularization was reported to arise early in the adenoma-carcinoma sequence in colorectal cancer (CRC), and the importance of angiogenesis in cancer progression has been established. Computed tomography (CT) perfusion (CTP) based on high temporal resolution CT images enables evaluation of hemodynamics of tissue in vivo by modeling tracer kinetics. CTP has been reported to characterize tumor angiogenesis, and to be a sensitive marker for predicting recurrence or survival in CRC. In this review, we will discuss the biomarker value of CTP in the management of CRC patients.

Preoperative hepatic CT perfusion as an early predictor for the recurrence of esophageal squamous cell carcinoma: initial clinical results.

Reports suggest that hepatic blood flow may have an association with cancer progression. The aim of the present study was to evaluate whether the hepatic blood flow measured by CT perfusion (CTP) may identify patients at high­risk for postoperative recurrence of esophageal squamous cell carcinoma (ESCC). Prior to surgery, hepatic CTP images were obtained using a 320-row area detector CT. The data were analyzed by a commercially available software based on the dual input maximum slope method, and arterial blood flow (AF, ml/min/100 ml tissue), portal blood flow (PF, ml/min/100 ml tissue) and perfusion index [PI (%) = AF/AF + PF x 100] were measured. These parameters were compared with the pathological stage and outcome of the ESCC patients. Forty-five patients with ESCC were eligible for this study. The median follow-up period was 17 months, and recurrences were observed in 9 patients (20%). The preoperative PI values of the 9 patients with recurrence were significantly higher than those of the 36 patients without recurrence (23.9 vs. 15.9, P=0.0022). Patients were categorized into the following two groups; high PI (>20) and low PI (<20). The recurrence-free survival of the low PI group was significantly better than that of the high PI group (P<0.0001). A multivariate analysis showed that a high PI was an independent risk factor for recurrence (odds ratio, 19.1; P=0.0369).Therefore, the preoperative PI of the liver may be a useful imaging biomarker for predicting the recurrence of patients with esophageal cancer.

Apparent diffusion coefficient correlation with oesophageal tumour stroma and angiogenesis.

OBJECTIVE: Because diffusion-weighted imaging (DWI) can predict the prognosis of patients with oesophageal squamous cell carcinoma (ESCC), we hypothesised that apparent diffusion coefficient (ADC) values might be correlated with the collagen content and tumour angiogenesis. The purpose of this study was to determine the correlation between ADC values of ESCC before treatment and oesophageal tumour stroma and angiogenesis. METHODS: Seventeen patients with ESCC were enrolled. The ADC values were calculated from the DWI score. Seventeen patients who had undergone oesophagectomy were analysed for tumour stroma, vascular endothelial growth factor (VEGF) and CD34. Tissue collagen was stained with azocarmine and aniline blue to quantitatively analyse the extracellular matrix in cancer stroma. Tissues were stained with VEGF and CD34 to analyse the angiogenesis. RESULTS: The ADC values decreased with stromal collagen growth. We found a negative correlation between the tumour ADC and the amount of stromal collagen (r = -0.729, P = 0.001), i.e. the ADC values decreased with growth of VEGF. We also found a negative correlation between the ADC of the tumours and the amount of VEGF (r = 0.538, P = 0.026). CONCLUSION: Our results indicated that the ADC value may be a novel prognostic factor and contribute to the treatment of oesophageal cancer. KEY POINTS: • Magnetic resonance apparent diffusion coefficient values inversely indicate tumour stromal collagen • There is also negative correlation between ADCs and vascular endothelial growth factor • ADC values may contribute to the treatment of oesophageal cancer.

Combined Legionella and Escherichia coli lung infection after a tsunami disaster.

Pulmonary infection after a tsunami is often polymicrobial and tends to form chronic pyogenic lung disease, necrotizing pneumonia, and empyemas. We report a combined pulmonary infection of Legionella and multiple antibiotic-resistant Escherichia coli in a previously well 75-year-old woman following immersion in tsunami waters 1 km inland from the Pacific coastline following the Tohoku Region Pacific Coast Earthquake of 2011. She needed drainage several times and the long-term use of multiple antibiotics according to the type of bacteria found and antibiotic susceptibility. We should be mindful of infections caused by multiple pathogens in the environment in Japan as a consequence of a tsunami disaster.

Role of perfusion CT in assessing tumor blood flow and malignancy level of gastric cancer.

BACKGROUND/AIMS: Intratumoral hemodynamics or tumor perfusion is useful in understanding the pathological background of the cancer. A parameter for a non-invasive, preoperative assessment of tumor perfusion has yet to be developed. METHODS: The study included 50 patients who underwent surgery for gastric cancer. Perfusion computed tomography (P-CT) was performed using a 16-row multidetector CT, and tumor blood flow (ml/min/100 g tissue) values were measured. We compared blood flow with histopathological characteristics and evaluated its correlation with microvessel density and tumor stromal density and calculated the ratio of vessels and stromal tissue. RESULTS: There was a significant decrease in blood flow in advanced tumor depth, peritoneal dissemination and undifferentiated subtypes. Cases with Lauren's diffuse type carcinoma were found to have decreased blood flow compared to the mixed or intestinal type. As for the stromal structure, despite the lack of correlation with microvessel density, blood flow significantly decreased with increased stromal density. CONCLUSIONS: Decreased blood flow value acquired from P-CT may reflect a progressive state of gastric cancer. The pathological background for this relation involves the tumor stroma. Tumor perfusion decreased as the stage and malignant character of the tumor advanced, and therefore P-CT could be a better strategy to estimate the malignancy level of cancer.