What if a prostate biopsy could reveal more than what a few samples might show? Transperineal Template Prostate Biopsy takes a systematic approach to prostate tissue sampling, using a template grid to guide needle placement across predetermined locations throughout the gland. Also known as transperineal template-guided mapping biopsy (TTMB), it allows urologists to examine tissue from multiple regions of the prostate for a more detailed assessment.
Understanding the technique, its potential benefits, and its limitations helps urology teams determine when template-guided sampling may be appropriate within the wider prostate cancer diagnostic pathway.
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What is Transperineal Template Prostate Biopsy?
Transperineal Template Prostate Biopsy is a systematic approach to prostate tissue sampling that uses a template grid to guide biopsy needles to predetermined locations throughout the prostate. Also known as transperineal template-guided mapping biopsy (TTMB), the procedure allows urologists to collect tissue samples from different regions of the gland for pathological examination.
Ultrasound guidance helps the urologist visualise the prostate and direct needle placement. The template provides a consistent reference for sampling different regions of the gland, including areas that may be difficult to reach using other biopsy approaches.
When is Template Mapping Biopsy used?
Template Mapping Biopsy may be considered when a more extensive assessment of the prostate is clinically appropriate. Common clinical situations include:
- Previous negative biopsy results: When earlier biopsies have not detected cancer but PSA results, MRI findings, or other clinical factors continue to raise suspicion.
- Persistent suspicion of prostate cancer: When the available investigations do not adequately explain the patient’s clinical findings.
- Assessment of areas that may have been missed: Systematic transperineal sampling can examine regions, including the anterior prostate, that may be challenging to sample with some transrectal approaches.
- Selected treatment-planning situations: Detailed sampling may be considered when additional information about the distribution of cancer is needed. However, mapping results do not guarantee that the exact extent or location of all cancer has been established.
The decision to perform template mapping depends on the individual patient’s history, imaging, previous biopsy results and overall clinical assessment. It is not necessary for every patient undergoing prostate biopsy.
How does the procedure work?
The procedure involves ultrasound-guided Prostate Biopsy Gun placement through a template grid, followed by systematic collection of tissue samples.
1. Patient Preparation
The clinical team reviews the patient’s medical history, PSA results, imaging, and previous biopsy findings. The appropriate anaesthetic approach and infection-prevention measures are determined according to the patient’s needs and local clinical protocols.
Traditional template mapping procedures often use general or local anaesthesia, although techniques and protocols vary between centres.
2. Ultrasound Visualisation of the Prostate
An ultrasound probe is positioned to provide images of the prostate. These images help the urologist assess the gland’s dimensions and guide the planned sampling positions.
The ultrasound system provides real-time visual guidance during needle placement.
3. Positioning the Template Grid
A template grid with multiple needle-entry holes is positioned against the perineum. The grid provides predefined entry points that help the operator direct the needle towards different regions of the prostate.
The grid, marked with alphabets A to G (horizontally) and 1 to 7 (vertically), allows the surgeon to map the prostate using exact coordinates. Grid holes may be spaced approximately 5 mm between each other, although the configuration varies by system.
4. Systematic Tissue Sampling
The biopsy gun is introduced through selected grid positions and advanced under ultrasound guidance. Multiple tissue cores are collected from the anterior, mid, and posterior areas (both left and right side) in order to get the best sample for diagnosis.
The sampling pattern is designed to cover the intended regions of the prostate. The number of cores depends on factors such as prostate volume and the clinical objective.
5. Specimen Labelling and Pathology
Each tissue core is placed in an appropriately labelled specimen container (Tissue cassette). Accurate labelling is important because it helps the pathology team associate each sample with its corresponding location.
The samples are examined under a microscope to determine whether cancer is present and to assess relevant pathological characteristics.
Equipment used for Template Mapping Biopsy
Template Mapping Biopsy requires equipment that supports ultrasound visualisation, controlled needle placement and systematic sampling.
Ultrasound System and Probe
The ultrasound system provides images of the prostate during the procedure. These images help the operator identify the gland’s boundaries and guide the biopsy needle.
Stepper Stabiliser System
A compatible stepper stabiliser can help position and secure the ultrasound probe. Controlled probe movement supports consistent imaging and positioning during the procedure.
Brachytherapy Template Grid
The template grid provides multiple needle-entry points arranged in a defined pattern. It is central to traditional template-guided mapping because it helps establish the sampling coordinates.
Prostate Biopsy Gun
The biopsy guns (18 G x 20 cm) are used to collect tissue cores from the planned locations. The equipment must be appropriate for the biopsy system and the operator’s technique.
Specimen Containers
Clearly labelled tissue cassettes help maintain the association between each tissue sample and its sampling location for pathological assessment.
What are the benefits of this procedure?
Template Mapping Biopsy offers several potential clinical advantages in appropriately selected patients.
- Systematic prostate coverage: A predefined sampling pattern enables tissue collection from multiple regions of the gland.
- Access to additional prostate regions: The transperineal route can facilitate sampling of areas that may be less accessible using certain transrectal approaches.
- Structured sample localisation: Recording the template coordinates for each core helps clinicians identify where individual samples were obtained.
- Additional diagnostic information: In patients with persistent suspicion of cancer following an earlier negative biopsy, more extensive sampling may identify disease that was not detected previously.
Template Mapping Biopsy vs Standard Prostate Biopsy
Template Mapping Biopsy and other prostate biopsy techniques differ in their sampling strategy, equipment, and clinical applications.
| Feature | Template Mapping Biopsy | Other Prostate Biopsy Techniques |
| Needle entry | Through the perineum | Through the perineum or rectal wall, depending on the technique |
| Sampling approach | Extensive, template-guided systematic sampling | May involve systematic sampling, MRI-targeted sampling or a combination |
| Needle guidance | Ultrasound with a template grid | Ultrasound, MRI-derived targeting and/or other guidance systems |
| Sample distribution | Multiple predefined locations across the prostate | Depends on the selected biopsy protocol |
| Typical clinical consideration | Selected cases requiring extensive sampling or further investigation | Commonly used for initial diagnosis and targeted or systematic assessment |
The term standard prostate biopsy covers several techniques. Some transperineal biopsies also use systematic sampling, and MRI-targeted biopsies can be combined with systematic cores. Therefore, the main distinction is the extent and template-based organisation of sampling rather than simply the route used to reach the prostate.
What are the risks and limitations?
As with other invasive prostate biopsy procedures, mapping biopsy has potential risks that should be discussed with the patient before the procedure. These may include:
- Blood in the urine or semen.
- Discomfort, bruising or bleeding around the biopsy site.
- Urinary retention, particularly following extensive sampling.
- Infection, despite the transperineal route avoiding passage through the rectal wall.
- Risks associated with the anaesthesia used.
Extensive sampling can increase the likelihood of temporary urinary difficulties in some patients. The procedure may also require more resources than less extensive biopsy approaches.
Although transperineal sampling avoids direct needle passage through the rectal wall, infection risk is not eliminated. Patient selection, procedural technique, and appropriate infection prevention measures remain important.
Is Template Mapping Biopsy Suitable for Every Patient?
Template Mapping Biopsy is not required for every patient with suspected prostate cancer. For many patients, contemporary diagnostic pathways use clinical assessment, PSA testing, prostate MRI and an appropriate combination of systematic and targeted biopsy.
The choice depends on the patient’s risk factors, previous investigations and local clinical guidance.
Template Mapping Biopsy may be useful when a more extensive sampling strategy is warranted, particularly in selected patients with persistent suspicion following previous negative biopsies.
Your treating urologist should assess whether the additional sampling is likely to provide clinically useful information. Book your consultation with the best consultant urologist near you.
Conclusion
Template Mapping Biopsy is a structured approach to prostate tissue sampling that uses a template grid and ultrasound guidance to collect samples from multiple regions of the prostate through the perineum.
It may provide additional diagnostic information in selected patients, particularly when previous biopsies have not resolved ongoing suspicion of prostate cancer. The procedure also relies on appropriate equipment, accurate sample labelling, and careful clinical planning.
FAQs
Is Template Mapping Biopsy the same as transperineal prostate biopsy?
No, Template Mapping Biopsy is a specific form of transperineal biopsy that uses a template grid to guide systematic sampling across the prostate. Transperineal biopsy is a broader category that also includes freehand and other targeted techniques.
How many samples are taken during Template Mapping Biopsy?
The number varies according to prostate size, the sampling protocol, and the clinical objective. Traditional mapping techniques may collect numerous cores to assess a broad distribution of prostate tissue.
Can Template Mapping Biopsy detect cancer missed by a previous biopsy?
It may detect cancer that was not identified previously because the sampling pattern can examine additional regions of the prostate. However, no biopsy technique guarantees detection of every cancer.
Is Template Mapping procedure performed under general anaesthesia?
Traditional template mapping procedures often use general or spinal anaesthesia. The anaesthetic approach depends on the technique, patient factors, and the treating centre’s protocol.
5. What is the role of a brachytherapy grid in the Template Mapping procedure?
A brachytherapy grid acts as a template for needle entry. Its predefined holes help the operator guide biopsy needles towards planned positions across the prostate under ultrasound guidance.
6. Is Template Mapping Biopsy used to plan focal prostate cancer treatment?
It may be considered in selected treatment-planning situations where detailed sampling is required. However, mapping biopsy does not establish the exact location and extent of every cancer focus with certainty, so its suitability for focal treatment planning requires careful clinical assessment.