Properties of head and neck squamous cell carcinoma (HNSCC) such as cellularity, vascularity, and glucose metabolism interact with each other. This study aimed to investigate the associations between diffusion-weighted imaging (DWI), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and positron emission tomography/computed tomography (PET/CT) in patients with HNSCC. Fourteen patients who were diagnosed with HNSCC were investigated using DCE-MRI, DCE, and ¹⁸fluoride-fluorodeoxyglucose PET/CT and evaluated retrospectively. Ktrans, Kep, Ve, and initial area under the curve (iAUC) parameters from DCE-MRI, ADC_max, ADC_mean, and ADCmin parameters from DWI, and maximum standardized uptake value (SUV_max), SUV_mean, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) parameters from PET were obtained. Spearman’s correlation coefficient was used to analyze associations between these parameters. In addition, these parameters were grouped according to tumor grade and T and N stages, and the difference between the groups was evaluated using the Mann-Whitney U test. Correlations at varying degrees were observed in the parameters investigated. ADC_mean moderately correlated with Ve (p=0.035; r=0.566). Ktrans inversely correlated with SUV_max (p=0.017; r=-0.626). iAUC inversely correlated with SUV_max, SUV_mean, TLG, and MTV (p<0.05, r≤-0.700). MTV (40% threshold) was significantly higher in T4 tumors than in T1-3 tumors (p=0.020). No significant difference was found in the grouping made according to tumor grade and N stage in terms of these parameters. Tumor cellularity, vascular permeability, and glucose metabolism had significant correlations at different degrees. Furthermore, MTV may be useful in predicting T4 tumors.

Background/aim: Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) can in vivo characterize tumor microvascular environment. The aim of the present study was to reveal the DCE-MRI findings and to determine the correlation between these findings and immunohistochemical data in head and neck squamous cell carcinoma (HNSCC). Materials and methods: Thirty-three patients diagnosed with primary HNSCC were evaluated retrospectively. DCE-MRI was conducted in all cases. CD34, CD105, and ki-67 expressions were analyzed with immunohistochemistry in tissue sections to determine micro-vessel density and proliferative activity. Results: The DCE-MRI is a successful technique in distinguishing tumor tissue from normal tissue. It was determined that Ve, Ktrans, and ki-67 values were significantly higher in high-stage tumors and there were positive correlations between the Ktrans value (by standard ROI) and CD34 MVDmax and CD34 MVDmean values. No statistically significant correlation was determined between other parameters in DCE-MRI and immunohistochemical data, and T stage. Conclusion: DCE-MRI could successfully differentiate tumor tissue in HNSCC. Furthermore, it was observed that DCE-MRI had the potential to reveal certain immunohistochemical information in vivo.

Aim: The COVID-19 pandemic has caused delays in breast cancer screening and diagnostic procedures. The aim of this research was to compare the status of breast cancer screenings and newly diagnosed breast cancer cases during the pandemic compared to the pre-pandemic period. Material and method: This retrospective study included patients with screening mammography, imaging-guided biopsies, and newly diagnosed breast cancer from March 2020– February 2021 (during-COVID-19) were compared with March 2019–February 2020 (pre-COVID-19). We compared numbers and distribution over time of mammography and biopsies between the time periods. In the breast cancer group; the stage at diagnosis and histopathological features of the tumor were also compared. Results: Compared to pre-pandemic mammography scans, a 44% decrease was observed in total during pandemic, the most significant being in April (-98%) and May (-93%). While there was a significant decrease in the number of biopsies in April (-100%) and May (-69%), it was seen that there was no decrease in the pandemic period when the whole year was looked at with a rebound increase that started with 29% in June. In the breast cancer group, there was a significant increase in the number of patients who were metastatic at the time of diagnosis compared to the pre-pandemic period (p=0.001). No significant difference was observed between the two groups in terms of tumor grade, hormone receptor status, or HER2 positivity (p>0.05). Conclusions: In this study, it was observed that both screening and diagnosis processes in breast cancer were significantly affected during the COVID-19 pandemic. It was observed that the delay in admission to the hospital in the first months of the pandemic resulted in an increase in patients who were metastatic at the time of diagnosis.