title: Combination of microbubbles and diagnostic ultrasound at a high mechanical index for the synergistic microwave ablation of tumours.
abstract: OBJECTIVE
  To determine whether combining microbubbles (MBs) with diagnostic ultrasound (US) at a high mechanical index (MI) could enhance the microwave (MW) ablation of tumours.
  
  
  METHODS
  Five therapeutic MW adjuvant protocols were studied: MW, MW + US, MW + US + MB, MW + US + NS (saline) and MW + MB. In 30 normal rabbit livers, the synergistic effects were evaluated via temperature, necrosis volume and histology. In 90 VX2 rabbit hepatic tumours, residual cells in the peripheral ablated tumours were examined via immunohistochemical assay and tumour growth. Additional 40 VX2 hepatic tumours were evaluated for ablation safety via blood assay and weight and for survival to 105 days. Results were compared using analysis of variance.
  
  
  RESULTS
  Compared with the other protocols, the ablation volumes in normal rabbit livers were significantly larger using the MW + US + MB protocol (p < .001). The histological examination was consistent with more efficient ablation in that protocol. In detecting residual cells, the apoptotic index was higher, the proliferating index was lower (p < .05), tumour growth was significantly smaller (p < .001), and the rabbits of the MW + US + MB T-Group survived longer (p < .05) than those of the other groups. Additionally, no damage to the liver function or blood cells was found in any of the protocols after ablation (p < .05).
  
  
  CONCLUSIONS
  MBs in combination with diagnostic US at a high MI showed potential synergy in the MW ablation of tumours in rabbits.
authors.affiliation: a Chongqing Key Laboratory of Ultrasound Molecular Imaging , Second Affiliated Hospital of Chongqing Medical University , Chongqing , China.
authors.forename: Jinshun
authors.initials: J
authors.lastname: Xu
authors.affiliation: a Chongqing Key Laboratory of Ultrasound Molecular Imaging , Second Affiliated Hospital of Chongqing Medical University , Chongqing , China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.affiliation: a Chongqing Key Laboratory of Ultrasound Molecular Imaging , Second Affiliated Hospital of Chongqing Medical University , Chongqing , China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Xu
authors.affiliation: b Department of Radiology , Central Hospital of Enshi Autonomous Prefecture , Hubei , China.
authors.forename: Xueqing
authors.initials: X
authors.lastname: Cheng
authors.affiliation: c Department of Ultrasound , Sichuan Provincial Cancer Hospital , Sichuan , China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: You
authors.affiliation: a Chongqing Key Laboratory of Ultrasound Molecular Imaging , Second Affiliated Hospital of Chongqing Medical University , Chongqing , China.
authors.forename: Yuanzhi
authors.initials: Y
authors.lastname: Yao
authors.affiliation: a Chongqing Key Laboratory of Ultrasound Molecular Imaging , Second Affiliated Hospital of Chongqing Medical University , Chongqing , China.
authors.forename: Jianxin
authors.initials: J
authors.lastname: Liu
authors.affiliation: a Chongqing Key Laboratory of Ultrasound Molecular Imaging , Second Affiliated Hospital of Chongqing Medical University , Chongqing , China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: a Chongqing Key Laboratory of Ultrasound Molecular Imaging , Second Affiliated Hospital of Chongqing Medical University , Chongqing , China.
authors.forename: Pan
authors.initials: P
authors.lastname: Li
authors.affiliation: d Department of Ultrasound , Second Affiliated Hospital of Chongqing Medical University , Chongqing , China.
authors.forename: Min
authors.initials: M
authors.lastname: Lu
keywords: Thermal ablation; cancer; contrast agent; ultrasound imaging