Simultaneous transrectal ultrasound and photoacoustic human prostate imaging
Menée à l'aide de modèles murins de cancer de la prostate et menée sur 20 patients présentant un niveau sérique élevé du PSA et parmi lesquels 5 sont atteints d'un cancer de la prostate, cette étude analyse la capacité d'une sonde, réalisant simultanément une échographie transrectale et un examen photoacoustique, à identifier en temps réel les caractéristiques anatomiques, vasculaires et moléculaires de la prostate
Molecular imaging can help improve detection of cancer, but some modalities require ionizing radiation, making them nonideal for repeated imaging. Kothapalli et al. developed a probe that could perform ultrasound and photoacoustic imaging simultaneously, two modalities that do not require ionizing radiation. Testing the transrectal ultrasound and photoacoustic device in vitro, in mouse models, and using excised human prostates demonstrated the ability to view anatomical features within tissue and vascular contrast within tumors. Administering a dye improved photoacoustic contrast when imaging the prostates of human subjects with cancer. This device allows for real-time anatomical, functional, and molecular imaging of the human prostate and could be easily adopted into clinical workflows.Imaging technologies that simultaneously provide anatomical, functional, and molecular information are emerging as an attractive choice for disease screening and management. Since the 1980s, transrectal ultrasound (TRUS) has been routinely used to visualize prostatic anatomy and guide needle biopsy, despite limited specificity. Photoacoustic imaging (PAI) provides functional and molecular information at ultrasonic resolution based on optical absorption. Combining the strengths of TRUS and PAI approaches, we report the development and bench-to-bedside translation of an integrated TRUS and photoacoustic (TRUSPA) device. TRUSPA uses a miniaturized capacitive micromachined ultrasonic transducer array for simultaneous imaging of anatomical and molecular optical contrasts [intrinsic: hemoglobin; extrinsic: intravenous indocyanine green (ICG)] of the human prostate. Hemoglobin absorption mapped vascularity of the prostate and surroundings, whereas ICG absorption enhanced the intraprostatic photoacoustic contrast. Future work using the TRUSPA device for biomarker-specific molecular imaging may enable a fundamentally new approach to prostate cancer diagnosis, prognostication, and therapeutic monitoring.
Science Translational Medicine , résumé, 2018