Influence of perfusion on high-intensity focused ultrasound prostate ablation: a first-pass MRI study
Marlène Wiart1, Laura Curiel2, Albert Gelet2,3
1Université de Lyon, Lyon, F-69003, France; INSA de Lyon, Villeurbanne, F-69621, France; Creatis CNRS, UMR 5220, Bron, F-69677, France; Inserm, U630, Bron, F-69677, France.
Abstract:
Our aim was to evaluate the influence of regional prostate blood flow (rPBF) on high-intensity focused ultrasound (HIFU) treatment outcome. A total of 48 patients with clinically localized prostate cancer were examined by dynamic contrast-enhanced (DCE)-MRI prior to HIFU therapy. A prostate-specific antigen (PSA) nadir threshold of 0.2 ng/ml was used to define the populations of responders and nonresponders. A dedicated tracer kinetic model, namely "monoexponential plus constant" (MPC) deconvolution, was implemented to provide quantitative estimates of rPBF. The results were compared with those obtained by semiquantitative (steepest slope, mean gradient) and quantitative (Fermi deconvolution) approaches. Of the four methods studied, quantitative rPBF obtained by MPC deconvolution proved the most sensitive to the perfusion changes encountered in this study. Furthermore, blood-flow values obtained with MPC deconvolution in the prostate and muscle (12 +/- 8 and 5 +/- 3 ml/min/100 g, respectively) were in good agreement with literature data. The mean pretreatment rPBF obtained with MPC deconvolution was significantly higher in nonresponders compared to responders (16 +/- 9 vs. 10 +/- 6 ml/min/100 g), suggesting a correlation between baseline perfusion and treatment outcome. The present work describes and validates the use of dynamic MRI to estimate rPBF in patients, which in the future may help to refine the conduct of HIFU therapy.
Insights
Regional prostate blood flow (rPBF) assessed by dynamic MRI before high-intensity focused ultrasound (HIFU) therapy can predict treatment success. Higher baseline rPBF in nonresponders suggests perfusion influences HIFU outcomes.
Area of Science:
- Medical Imaging
- Oncology
- Biophysics
Background:
- High-intensity focused ultrasound (HIFU) is a focal therapy for localized prostate cancer.
- Predicting HIFU treatment outcomes remains a challenge.
- Regional prostate blood flow (rPBF) is a potential biomarker for treatment response.
Purpose of the Study:
- To evaluate the influence of regional prostate blood flow (rPBF) on high-intensity focused ultrasound (HIFU) treatment outcomes.
- To validate quantitative rPBF estimation using dynamic contrast-enhanced MRI (DCE-MRI) and a monoexponential plus constant (MPC) deconvolution model.
Main Methods:
- 48 patients with localized prostate cancer underwent DCE-MRI before HIFU.
- Quantitative rPBF was estimated using MPC deconvolution and compared with semiquantitative and Fermi deconvolution methods.
- Responders and nonresponders were defined by prostate-specific antigen (PSA) nadir < 0.2 ng/ml.
Main Results:
- Quantitative rPBF by MPC deconvolution was the most sensitive method for detecting perfusion changes.
- Pretreatment rPBF was significantly higher in nonresponders (16 ± 9 ml/min/100 g) than in responders (10 ± 6 ml/min/100 g).
- MPC deconvolution provided rPBF values for prostate and muscle consistent with literature data.
Conclusions:
- Dynamic MRI-based quantitative rPBF estimation is a validated method for assessing prostate perfusion.
- Baseline rPBF may correlate with HIFU treatment outcomes in prostate cancer.
- This technique could help refine HIFU therapy planning and execution.
