Renal angiomyolipomas. Possibilities of CT perfusion implementation for assessment of therapeutic effect of renal angiomyolipomas embolization. A review of literature and clinical observations

Purpose of the study: to analyze the data of domestic and foreign literature on the use of computed tomographic perfusion (CTP) in the diagnosis of kidney diseases, including patients with benign and malignant kidney tumors. To evaluate the prospects of using this technique to determine the effectiveness of various minimally invasive interventions (cryotherapy, various types of thermoablation, arterial embolization) for the treatment of patients with renal tumors, as well as for follow-up of patients in these groups. Material and methods. A search of scientific papers published in the electronic databases PubMed, Google Scholar, E-library using the key words “angiomyolipoma”, “kidney”, “transarterial embolization of tumors”, “CT-perfusion of the kidneys” was carried out. In the article the materials of 40 literature sources for the last 10 years, including 25 articles - for the last 5 years, devoted to the mentioned subject are considered. The authors present their own clinical cases demonstrating the CTP application usefulness to assess the therapeutic effect of renal angiomyolipomas (rAML) transarterial embolization (TAE). Results. The conducted literature review showed that renal CTP is a noninvasive technique that allows differential diagnostics between benign tumors (low-fat rAML and oncocytoma), as well as with malignant renal neoplasms, to reveal features of different histological variants of renal cell cancer. In addition, there are works devoted to the application of CTP in the evaluation of the efficacy of minimally invasive techniques such as cryoablation, TAE (in the treatment of renal cell cancer (RCC) and rAML, respectively), as well as target therapy for RCC. According to the preliminary results of our clinical cases, the main CTP parameters allowed to detail the structure of rAML (before and after TAE), blood flow features of its microcirculatory level and to detect recurrence on the basis of progressive growth of perfusion values with simultaneous reduction of tumor volume, which demonstrates the possibilities of using CTP as an additional monitoring technic after surgical treatment. Conclusion. Despite the availability of papers analyzing the use of CTP as a technique to assess renal tumor angiogenesis, many gaps remain in its use as a clinical potential in the evaluation of early and subsequent follow-up in the cases of renal tumors surgical treatment. To date, there is no evident and thoroughly validated imaging method for embolized tumors. There are no works on studying the possibilities of CTP in assessing the therapeutic effect of rAML embolization. The results of our own clinical cases allowed us to suggest that CTP can be used as an additional technique for monitoring rAML after surgical treatment such as TAE and detecting disease recurrence by assessing tumor neoangiogenesis.