Dr Les Thompson and Dr Morgan Pokorny pioneered the development of MRI-guided prostate biopsy in Australia at the Wesley Hospital, Brisbane. Following on from their successful study comparing standard transrectal ultrasound guided prostate biopsy (in which 12-18 needle samples are taken at random via the rectum) to MRI-guided biopsy (2-4 needles taken of specific targets using MRI-guidance), this technique has now become a mainstay of Dr Pokorny's diagnostic toolkit for establishing the diagnosis of prostate cancer.
The advantages of MRI-guided biopsy include:
- Only 2-4 needles samples are taken.
- We target the suspicious lesion seen on MRI directly - no guesswork is needed. This means the most aggressive part of the tumour is correctly sampled, allowing more informed decision-making afterwards. This method is far superior to the old TRUS-biopsy technique, and is superior to MRI-ultrasound fusion, which relies on fusing a MRI-scan acquired earlier, to an ultrasound scan. This is done manually by the operator, and is prone to a number of errors.
- We can target and correctly sample lesions in difficult locations for transrectal ultrasound guided biopsy, such as the front of the prostate or very deep down at the apex region - these sites are often missed by other biopsy methods.
- No general anaesthetic or deep sedation needed, we only give a small dose of Fentanyl to relax our patients
- Procedure takes only 15-20 min for a single lesion.
- We have observed a lower risk of infection with the smaller number of needles taken with MRI biopsy, compared to the old method.
Dr Pokorny and Dr Thompson perform MRI guided biopsy at the Wesley Medical Imaging suites at the Wesley Hospital. These are performed on Tuesdays, Wednesdays and Thursdays. The procedure is not painful, and lasts about 20 minutes per lesion - most patients have only one lesion that needs biopsy, some have two. No sedation or anaesthetic is required, but patients do need a friend or family member to drive them home afterwards. The procedure is covered before and after by antibiotics prescribed to the patient, and a strong dose of antibiotic is given intravenously at the time of the procedure.
The procedure is performed with the patient lying on their stomach in the MRI machine, comfortably padded and wearing headphones. Several short scans of 10 seconds duration are taken to position the biopsy device in the rectum, after which a longer scan of 3 minutes is taken to assist final positioning. After this a few more 10-second scans are taken to line up the needle-guide with the lesion, and two biopsies are taken. A scan is taken with the biopsy needle deployed in the lesion, to ensure that no mistakes are made.
The results of the biopsy are usually available the following day, and patients can usually be seen on that day by Dr Pokorny for discussion of the results.