CT-perfusion in the diagnosis of oropharyngeal cancer and monitoring of chemoradiotherapy.

Abstract

Purpose of the study: to identify diagnostic effectiveness of the CT perfusion method in diagnosing squamous cell carcinoma of the oropharynx and in assessing dynamic changes in the affected area after chemoradiotherapy.Materials and methods. The results of CT perfusion and CT with intravenous contrast were analyzed in 27 patients aged 40 to 76 years, who were divided into three groups: 1) a control group of patients with suspected oropharyngeal tumors – 9 people (33.4%); 2) group of primary (untreated) patients – 8 people. (29.6%) with a verified diagnosis of squamous cell carcinoma; 3) a group of patients with this diagnosis only after chemoradiotherapy – 10 people (37.0%).Results. Our own algorithm for CT perfusion of the oropharynx region was developed. Digital indicators characterizing the presence of tumor tissue in the tissues of the oropharynx were determined: arterial blood flow (AF) and blood volume (BV). When studying CT perfusion indicators, the following was established: in the group of untreated patients, in contrast to the control group of patients, the values of equivalent blood volume (BV), arterial blood flow velocity (AF) and permeability (FE) were statistically significantly increased. Whereas in patients after chemoradiation treatment, compared with the group of untreated patients, CT perfusion indices were statistically significantly reduced in the following parameters: equivalent blood volume (BV), arterial blood flow velocity (AF). The vascular permeability indicator (FE) is only of secondary importance in identifying the tumor process. Analysis of the results of CT perfusion in patients after chemoradiation treatment revealed an almost complete restoration of tissue perfusion indices in terms of AF and BV relative to perfusion indices in patients in the control group.Conclusion. The results of our study indicate the diagnostic effectiveness of CT perfusion in detecting oropharyngeal cancer and in assessing the corresponding changes in the affected area that occur after chemoradiotherapy. Changes in CT perfusion parameters are associated with microcirculation in the tumor area, which is confirmed by a statistically significant decrease in BV and AF parameters after chemoradiotherapy.