{"entity":{"id":"template-mapping-biopsy","kind":"term","name":"Template mapping biopsy (transperineal template prostate mapping)","aka":["transperineal template mapping biopsy","template prostate mapping","TPM biopsy","mapping template biopsy","transperineal template biopsy","5 mm template mapping biopsy"],"tldr":"A thorough biopsy done under general anaesthetic through the skin behind the scrotum, using a grid to sample the whole prostate systematically. It gives the most complete picture available short of removing the gland, and for that reason it is used as the yardstick in research rather than as a routine test.","summary":"A template biopsy takes transperineal core biopsies through a brachytherapy grid, usually two to three cores from each of eight sites, under general anaesthetic. A mapping template biopsy is the exhaustive version: NICE's own glossary defines it as systematic sampling of 20 sites with two or three cores per site, sometimes meaning more than 50 cores from one gland. Sampling the gland on a fixed grid, typically at 5 millimetre intervals, is what makes it a near-complete map rather than a sample, and going through the perineal skin rather than the rectal wall greatly reduces the risk of sepsis that transrectal biopsy carries.\n\nIts role is as a reference standard. PROMIS used it for precisely that: 576 men with prostate-specific antigen up to 15 nanograms per millilitre and no previous biopsy had 1.5 Tesla multiparametric magnetic resonance imaging, then both transrectal ultrasound-guided biopsy and template prostate mapping biopsy, each read blind to the others. Comparing a scan against the standard biopsy it is meant to replace answers nothing, because that biopsy is itself inaccurate; comparing both against an exhaustive mapping biopsy is what produced the numbers that changed the pathway, with the scan 93 percent sensitive and the standard biopsy 48 percent sensitive for clinically significant cancer. Of 576 men completing all three tests, 408 (71 percent) had cancer on mapping biopsy and 230 (40 percent) had clinically significant cancer.\n\nIt is not a routine test, and in the United Kingdom it is explicitly not one. NICE NG131 recommendation 1.2.5 says do not offer mapping transperineal template biopsy as part of an initial assessment unless as part of a clinical trial. The reasons are the general anaesthetic, the theatre time, the acute urinary retention that follows a heavily sampled gland, and the overdiagnosis that comes with sampling everything: a test that finds every cancer in a gland finds a great many cancers that were never going to matter. It remains in use in research, in imaging validation, and in selected clinical situations such as planning focal therapy or resolving a persistently raised prostate-specific antigen after repeated negative biopsies. PROMIS itself reported serious adverse events in 44 of 740 enrolled men (5.9 percent), including 8 cases of sepsis, a reminder that the reference standard has harms of its own.","asOf":"2026-09-25","wikipedia":"https://en.wikipedia.org/wiki/Prostate_biopsy","links":[{"label":"NICE NG131: terms used in this guideline (template biopsy and mapping template biopsy)","url":"https://www.nice.org.uk/guidance/ng131/chapter/Terms-used-in-this-guideline"},{"label":"NICE NG131: prostate cancer, diagnosis and management (recommendations)","url":"https://www.nice.org.uk/guidance/ng131/chapter/Recommendations"},{"label":"Ahmed et al., The Lancet 2017 (PROMIS): diagnostic accuracy of multiparametric MRI and TRUS biopsy in prostate cancer","url":"https://doi.org/10.1016/s0140-6736(16)32401-1"}],"tags":["gu","prostate-glossary"],"related":["paper-ahmed-promis-multiparametric-mri-lancet-2017","paper-precision-mri-targeted-biopsy-nejm-2018","pi-rads","whole-mount-pathology","idea-prostate-per-lesion-mri-audit-before-focal-treatment"],"cancers":["prostate","prostate-low-risk","prostate-intermediate-risk","prostate-high-risk"],"sections":["diagnostics","surgery","imaging"],"technologies":["mri","prostate-screening-psa-mri"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["pi-rads","whole-mount-pathology","gleason-grade-group","overdiagnosis","acute-urinary-retention","psa"],"trials":[],"people":[],"bottlenecks":["b-early-detection","b-overdiagnosis","b-biomarker-validation"],"keyPapers":["paper-ahmed-promis-multiparametric-mri-lancet-2017","paper-johnson-mpmri-individual-foci-eur-urol-2019"],"journals":[],"dependsOn":[],"notes":["Template, mapping template and targeted biopsy are three different operations. A template biopsy samples eight sites on a grid. A mapping template biopsy samples 20 sites and may take over 50 cores (NICE NG131's own definitions). A magnetic resonance imaging-targeted biopsy samples only what the scan flagged, which is what NG131 1.2.3 offers at a Likert score of 3 or more and what the modern pathway is built on.","Transperineal is a route, not a thoroughness. Most United Kingdom centres have moved their routine biopsies from transrectal to transperineal to reduce sepsis, often under local anaesthetic, and that is a different procedure from a mapping template biopsy under general anaesthetic. A man told he is having a transperineal biopsy is not necessarily having 50 cores.","Why the most accurate test is the one you are advised not to have. Mapping biopsy finds more cancer than any other test short of removing the gland, and much of the extra cancer it finds is exactly the low-grade disease the pathway now tries not to find. Accuracy and benefit are not the same thing in a disease with this much overdiagnosis, which is the whole reason NG131 restricts it to trials."],"category":"Procedures"},"route":"/terms/template-mapping-biopsy/","neighbours":{"paper":[{"id":"paper-johnson-mpmri-individual-foci-eur-urol-2019","kind":"paper","name":"Detection of individual prostate cancer foci via multiparametric magnetic resonance imaging","route":"/key-papers/paper-johnson-mpmri-individual-foci-eur-urol-2019/"},{"id":"paper-precision-mri-targeted-biopsy-nejm-2018","kind":"paper","name":"PRECISION: MRI-targeted or standard biopsy for prostate cancer diagnosis","route":"/key-papers/paper-precision-mri-targeted-biopsy-nejm-2018/"},{"id":"paper-ahmed-promis-multiparametric-mri-lancet-2017","kind":"paper","name":"PROMIS: diagnostic accuracy of multiparametric MRI and TRUS biopsy in prostate cancer","route":"/key-papers/paper-ahmed-promis-multiparametric-mri-lancet-2017/"}],"term":[{"id":"acute-urinary-retention","kind":"term","name":"Acute urinary retention","route":"/terms/acute-urinary-retention/"},{"id":"gleason-grade-group","kind":"term","name":"Gleason score / Grade Group","route":"/terms/gleason-grade-group/"},{"id":"overdiagnosis","kind":"term","name":"Overdiagnosis","route":"/terms/overdiagnosis/"},{"id":"pi-rads","kind":"term","name":"PI-RADS (Prostate Imaging Reporting and Data System)","route":"/terms/pi-rads/"},{"id":"psa","kind":"term","name":"PSA (prostate-specific antigen)","route":"/terms/psa/"},{"id":"whole-mount-pathology","kind":"term","name":"Whole-mount pathology","route":"/terms/whole-mount-pathology/"}],"idea":[{"id":"idea-prev-prostate-as-triggered-biopsy","kind":"idea","name":"Prostate active surveillance without scheduled biopsies: MRI and blood tests decide","route":"/ideas/idea-prev-prostate-as-triggered-biopsy/"},{"id":"idea-prostate-per-lesion-mri-audit-before-focal-treatment","kind":"idea","name":"Publish a per-lesion miss rate for every prostate MRI service before it is allowed to guide focal treatment","route":"/ideas/idea-prostate-per-lesion-mri-audit-before-focal-treatment/"}],"cancer":[{"id":"prostate-high-risk","kind":"cancer","name":"Localised prostate cancer, high and very high risk","route":"/cancers/prostate-high-risk/"},{"id":"prostate-intermediate-risk","kind":"cancer","name":"Localised prostate cancer, intermediate risk","route":"/cancers/prostate-intermediate-risk/"},{"id":"prostate-low-risk","kind":"cancer","name":"Localised prostate cancer, very low and low risk","route":"/cancers/prostate-low-risk/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"}],"section":[{"id":"diagnostics","kind":"section","name":"Diagnostics & Biomarkers","route":"/fronts/diagnostics/"},{"id":"imaging","kind":"section","name":"Imaging","route":"/fronts/imaging/"},{"id":"surgery","kind":"section","name":"Surgery & Interventional","route":"/fronts/surgery/"}],"technology":[{"id":"mri","kind":"technology","name":"MRI","route":"/technologies/mri/"},{"id":"prostate-screening-psa-mri","kind":"technology","name":"PSA and MRI-first prostate cancer screening","route":"/technologies/prostate-screening-psa-mri/"}],"bottleneck":[{"id":"b-biomarker-validation","kind":"bottleneck","name":"Biomarkers are not validated or standardised","route":"/bottlenecks/b-biomarker-validation/"},{"id":"b-overdiagnosis","kind":"bottleneck","name":"Overdiagnosis and false alarms","route":"/bottlenecks/b-overdiagnosis/"},{"id":"b-early-detection","kind":"bottleneck","name":"The hardest cancers are found late","route":"/bottlenecks/b-early-detection/"}]}}