METHOD FOR POSTOPERATIVE EVALUATION OF CRYOABLATION ZONE IN TREATMENT OF RENAL CANCER Russian patent published in 2022 - IPC A61B8/08 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to ultrasound diagnostics, and can be used for postoperative assessment of the cryoablation zone in the treatment of kidney cancer. An ultrasound examination (ultrasound) is performed with an assessment of the shape, structure, contour, echogenicity, and the presence of blood flow. Additionally, ultrasound with echocontrast (ECU) is performed in the area of ​​cryoablation for 1-2 days, then repeated after 3, 6 months and after a year. Ultrasonic contrast agent (UCA) is injected in a volume of 1.5-2.0 ml. The patient is asked to hold his breath at the moment the drug appears in the cortical substance of the kidney and at the time it begins to be washed out of the kidney. To assess the zone of cryoablation, 5 perfusion contrast patterns are used. The pattern of reactive changes is a rounded zone or an irregularly shaped zone with an area of ​​peripheral edema, characterized by the flow of a contrast agent, and an area of ​​central necrosis. The residual tumor pattern is a zone with pronounced asymmetry, residual parietal formation and a zone of necrosis. The pattern of the necrosis zone is a rounded zone in the form of an anechoic avascular area with no contrast agent entering the structure of the ablation zone, has clear contours and a homogeneous structure. The pattern of fibrotic changes is a zone with the presence of fibrous septa without accumulation of a contrast agent with a possible background accumulation in the structure of the septa. The recurrence pattern is a zone with the presence of a nodular formation, characterized by an earlier inflow and washout of the contrast agent in comparison with the surrounding parenchyma. At the same time, the pattern of recurrence corresponds to tumor recurrence, the pattern of residual tumor corresponds to residual malignant tissue, the pattern of fibrotic changes corresponds to the formation of scar tissue, the pattern of necrosis corresponds to the formation of a necrosis zone, the pattern of reactive changes corresponds to a necrosis zone with peripheral inflammation.

EFFECT: method provides an assessment of the cryoablation zone due to contrast patterns.

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