Blood perfusion disruption and reperfusion after low-frequency ultrasound combing microbubbles on prostate cancer xenografts in nude mice / 中华超声影像学杂志

ABSTRACT

Objective To explore the duration of blood blocking effect and recovery process induced by low-frequency ultrasound combining microbubbles (USMB) on prostate cancer xenografts.Methods A total of 88 nude mice undergoing USMB was studied.Contrast enhanced ultrasound,Hemotoxylin and eosin staining,and modified Martius-Sarlet-Blue staining were used to compared the average peak intensity(API),time to peak intensity(TP) and histological alteration before and after treatment.Results Immediately after the treatment,the tumor contrast perfusion completely disappeared,API dropped from 68.63±5.25 to 18.01±2.73 (P0.05).From post-3 hours after treatment ,the tumor perfusion began a process of perfusion recovery,and showed nodular or large patch of heterogeneous enhancement.API at 3 hours after treatment was 51.99±6.20 (P0.05,vs pre-treatment).Histological examinations showed that,immediately after treatment,microvessels severely dilated,ruptured and intravascular and extravascular thrombi formed.At 30 minutes,1-hour and 2-hour after treatment,extravascular thrombi and hematomas gradually disappeared.From 3-hour after treatment,vessel dilation was lessened,and intravascular thrombi gradually shrank.At 12-hour after treatment,microvessels had almost fully recovered as pre-treatment.Conclusions USMB could block blood perfusion of prostate cancer xenografts in nude mice for 2 hours.The blood reperfusion is probably mainly caused by thrombolysis in microvessels.