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TRUS biopsy

TRUS Biopsy

This is easily done in the clinic under local anaesthesia to confirm prostate cancer. Prostate cancer is suspected when the PSA (prostate specific antigen) level is > 4 ug/L or an abnormal nodule is felt in the prostate. An ultrasound probe slightly larger than a finger is inserted into the anus. After measuring the size of the prostate, local anaesthesia is injected around the prostatic nerves. Some 12 biopsies are taken using a small spring-loaded needle. The whole procedure takes 15 to 20 minutes and the histology results is ready by the 3rd day.

Normally, the accuracy rate of detecting prostate cancer is > 95%. However, if the PSA continues to rise over the years, a repeat biopsy may be needed as the cancer may initially be so small that it can be missed at the first sampling.

Standard 12-core biopsy template can still miss a small cancer

MRI-Ultrasound Fusion Biopsy

To improve the accuracy rate, the ultrasound image can be fused with the MRI image to target the suspicious areas. This makes the biopsy more precise and reduce the number of samples that need to be taken. A special software program is required for this and the MRI scan has to be a recent one. It takes longer to do and costs more because of the added cost of the MRI and image fusion process.

Complications include:

  • This is more common in diabetics and if there is underlying prostate infection. With antibiotics, the risk of severe infection should be < 5%. The symptoms are burning pain during urination, bloody urine and high fever. If this happens, hospital admission for intravenous antibiotics is needed
  • bloody urine. This usually clears by the 3rd day but if excessive, blood clots can form and block the bladder causing painful retention of urine. If this happens, catheterisation and washout of the clots is needed
  • bleeding from the anus. This tends to occur in those who have pre-existing piles. It usually stops the next day
  • acute retention of urine. This is more likely if the prostate is large and if the patient has untreated BPH. It is due to acute prostate swelling which then compresses the urethra to block the bladder. A Foley catheter will need to be inserted for a few days

Desired outcomes:

  • minimal pain during biopsy
  • minimal anal bleeding
  • no clot retention of bladder
  • no severe sepsis needing hospitalisation (1% occurrence)