​For the first time, magnetic resonance guided focused ultrasound (MRgFUS) is being used for the treatment of prostate cancer patients.

Eighteen patients with localised low-risk prostate cancer have been treated worldwide so far, including seven patients who are part of the clinical trials conducted by Singapore General Hospital (SGH), and National Cancer Centre, Singapore (NCCS).

Prostate cancer is the third most common cancer in our rapidly greying population, afflicting men even in their early 40s. Four in 100 prostate cancer patients die from this disease. In Singapore, prostate cancer is occurring four times more frequently compared to 30 years ago.

Treatment options for prostate cancer include prostatectomy (surgical removal of the prostate gland), radiation therapy, brachytherapy (implantation of radioactive seeds), and cryotherapy. Ultrasound guided high intensity focused ultrasound (HIFU) has also been used, outside the US, to treat prostate cancer.

“Unfortunately current treatment alternatives are accompanied by lasting side effects which significantly impact the quality of life of prostate cancer patients. The most common are incontinence and impotence”, said A/Prof Christopher Cheng, Head and Senior Consultant, Department of Urology, SGH.

“Since the introduction of PSA screening tests, prostate cancer is diagnosed at an earlier stage, increasing the necessity for a treatment option that minimises the side effects. This non-invasive method has been designed to provide effective treatment while minimising the debilitating side effects caused by damage to functional areas of the prostate and surrounding organs and structures. Patients may be able to return to normal life within a day or two while maintaining their quality of life”, said Prof Cheng.

Magnetic Resonance Guided Focused Ultrasound (MRgFUS)

MRgFUS which has been in clinical use for the treatment of uterine fibroids globally and bone metastases outside of the US, is an image guided, non-invasive robotic surgery system that integrates real time MRI to visualise the tumor, surrounding tissue and the energy delivery path. The technology concentrates high levels of heat on a target site to destroy the cancerous tumor but does not spill over to nearby healthy tissue, potentially causing damage or patient complications. The use of real-time 3D MR thermometry provides accurate monitoring of the treatment outcome and ability to adjust the treatment according to specific patient physiology, in real time.


For prostate cancer therapy, the major expected benefits of the non-invasive treatment include:
  • Low complication rate
  • Non-invasive treatment, patients back to their life within a day or two
  • Non-ionized radiation
  • Single session therapy
  • Real time MR thermometry monitoring that is used to control treatment outcome during treatment

“During MRgFUS treatments, which are non invasive and performed on an outpatient basis, patients lie on a table while doctors use the visual capabilities of magnetic resonance imaging to direct hundreds of individual and normally harmless sound waves at a single treatment point deep inside the body”, said Dr James Khoo, Head and Senior Consultant, Oncologic Imaging, NCCS.

"When they intersect, ultrasound waves have enough energy to destroy tumor cells, much like sun beams can be focused with a magnifying glass to burn a hole through a piece of paper. The technology is so precise that it can treat sites as small as a millimeter, which is about half the size of a grain of rice", said Dr Khoo.