BACKGROUND: High-intensity focused ultrasound (HIFU) is a promising treatment method for many common cancers, including prostate cancer. Magnetic resonance image (MRI) guidance of HIFU permits targeting and monitoring of therapy. A prototype MRI-compatible positioning device that navigates a HIFU transducer was designed, fabricated and tested. MATERIALS AND METHODS: The positioning device has two PC-controlled and one manually driven stage that allow endorectal access to the prostate. The positioning device was constructed using a 3-D rapid prototype manufacturing device. Software was developed that controls the motion of the positioning device and enables activation of a HIFU transducer. In vitro testing of the system was performed in a 1.5T MRI scanner using ex vivo turkey tissue. Optical encoders were employed to enhance the accuracy of this positioning device. RESULT: The positioning device was successfully tested for MRI compatibility. The movement error of the positioning device is approximately 20 [Formula: see text]m. The robot has the ability to accurately move the transducer for creation of discrete and overlapping lesions. CONCLUSION: An MRI-compatible HIFU positioning system was developed that has the ability to create thermal lesions with MRI guidance for endorectal treatment of prostate cancer.
BACKGROUND: High-intensity focused ultrasound (HIFU) is a promising treatment method for many common cancers, including prostate cancer. Magnetic resonance image (MRI) guidance of HIFU permits targeting and monitoring of therapy. A prototype MRI-compatible positioning device that navigates a HIFU transducer was designed, fabricated and tested. MATERIALS AND METHODS: The positioning device has two PC-controlled and one manually driven stage that allow endorectal access to the prostate. The positioning device was constructed using a 3-D rapid prototype manufacturing device. Software was developed that controls the motion of the positioning device and enables activation of a HIFU transducer. In vitro testing of the system was performed in a 1.5T MRI scanner using ex vivo turkey tissue. Optical encoders were employed to enhance the accuracy of this positioning device. RESULT: The positioning device was successfully tested for MRI compatibility. The movement error of the positioning device is approximately 20 [Formula: see text]m. The robot has the ability to accurately move the transducer for creation of discrete and overlapping lesions. CONCLUSION: An MRI-compatible HIFU positioning system was developed that has the ability to create thermal lesions with MRI guidance for endorectal treatment of prostate cancer.
Authors: Axel Häcker; Kai Uwe Köhrmann; Walter Back; Oliver Kraut; Ernst Marlinghaus; Peter Alken; Maurice Stephan Michel Journal: BJU Int Date: 2005-07 Impact factor: 5.588