Specific characteristics of the magnetic resonance imaging for transarterial chemoembolization with drug-saturated microspheres in oncogynecology

Abstract

Background: Magnetic resonance imaging (MRI) is used for the staging and assessment of treatment results of female pelvic tumors. The inclusion of transarterial chemoembolization (TACE) with drug-saturated microspheres into the treatment regimen puts a question to the radiologist: what TACE characteristics should be taken into account for the correct interpretation of the treatment results?
 Aim: To determine the main MRI parameters that characterize the results of TACE in the treatment of women with primary and recurrent pelvic tumors.
 Materials and methods: We performed a retrospective observational study of 80 patients with primary tumors (group 1) and 20 patients with recurrent tumors (group 2) of the small pelvis, complicated by tumor bleeding, who underwent 121 TACE procedures from 01.09.2015 to 01.12.2021 and were followed up to May 31, 2022. The study inclusion criteria were as follows: compliance with the approved protocol and time points for pelvic MRI. TACE results were evaluated according to RECIST 1.1.
 Results: In 100% of the cases in the groups 1 and 2, bleeding was controlled within 24 hours. In group 1, partial response was achieved in 48% (n = 38), complete response in 15% (n = 12), stabilization in 37% (n = 30), without any progression in all patients. In group 2, partial response was achieved in 27% (n = 5), complete response in 11% (n = 2), stabilization in 62% (n = 13), without any progression, as well. When comparing the mass volumes, recurrent tumors were significantly more responsive to TACE. The type of tumor growth was infiltrative (n = 25), expansive (n = 55), and mixed (n = 20). No significant differences in volume changes depending on the type of tumor growth were found. Eight women had undergone non-targeted ovarian embolization related to the type of blood supply. There were no cases of non-targeted embolization of the abdominal organs and the bladder, even with existing abnormal collateral vasculature.
 Conclusion: According to this data, the results of TACE for primary and recurrent pelvic tumors are characterized with the following MRI parameters: 1) hemostatic and cytostatic effects of TACE are manifested independently of each other; 2) tumor volume reflects changes after TACE to a greater extent than changes in linear dimensions; 3) there are cases of non-targeted ovarian embolization.