A template biopsy is a new way of more accurately assessing and mapping the prostate compared with the standard prostate biopsy. It is very valuable for men who have had repeated negative biopsies but are judged to be at high risk of having prostate cancer.
How does it work?
The term ‘template’ refers to a plate which was developed to provide precise mapping of the prostate. It was originally developed for brachytherapy, during which needles are inserted through holes in the template to exactly position radioactive seeds within the prostate.
By using the same template during a biopsy, the urologist is able to accurately map where each tissue sample is taken from and ensure the entire prostate is sampled. The template biopsy is also carried out at a different angle to the standard biopsy, sometimes called the TRUS biopsy. The needles are inserted through the perineum (the area between the scrotum and anus) which means there is less bleeding and discomfort for the patient compared with the TRUS biopsy.
The angle of a template biopsy also allows for improved sampling of the central and anterior sections of the prostate than a TRUS approach.
Why is has the template biopsy been introduced?
For the majority of patients, the standard TRUS biopsy is an effective way of diagnosing prostate cancer. However between 10 and 30 per cent of patients will be given what is called a ‘false negative’ result. This means the biopsy is negative, but prostate cancer is present.
The high false negative rate occurs because of the imprecise nature of the standard TRUS biopsy. The standard procedure involves inserting an ultrasound probe into the back passage (rectum). A needle is then placed down the shaft of the probe, through the wall of the rectum and into the prostate.
The procedure takes place under the guidance of the ultrasound image on a screen. Although this image helps us to measure the size of the prostate, it lacks detail and precision. Needles are inserted in between six and 12 different places, with the aim of ensuring all areas of the gland are sampled. Even in experienced hands, it is inevitable that for some patients, the needle will miss the cancerous sections of the prostate.
It is important to note that template biopsy should not be the first line diagnostic test for prostate cancer. For the majority of patients, a TRUS biopsy will be an effective diagnostic tool. But for those high risk patients with repeated negative tests, template biopsy offers an important and valuable new method.
What experience is there of the template biopsy?
Template biopsy was first introduced in America and is gradually being introduced in a small number of specialist urological centres now in the UK. Evaluations of its effectiveness are very promising. One study, entitled Evaluation of a novel precision template-guided biopsy system for detecting prostate cancer1 involving 140 patients concludes: “Template-guided biopsy potentially produces a higher cancer detection rate and more accurate assessment of grade.”
1 Study authors Ifeanyichukwu I. Megwalu, Genoa G. Ferguson, John T. Wei , Vladimir Mouraviev , Thomas J. Polascik, Samir Taneja, Linda Black, Gerald L. Andriole and Adam S. Kibel Division of Urology, Siteman Cancer Center, Washington University School of Medicine, St. Louis, MO, Department of Urology, University of Michigan School of Medicine, Ann Arbor, MI, Division of Urology, Duke University School of Medicine, Durham, NC, and Department of Urology, New York University School of Medicine, New York, NY, USA