{"entity":{"id":"idea-bio2-localise-the-mrd","kind":"idea","name":"When the blood test is positive, hunt for the lesion with sensitive imaging","aka":[],"tldr":"A positive blood test tells you cancer is back but not where. Combining whole-body MRI with modern PET tracers may find a single spot that can be zapped.","summary":"Patients who are ctDNA-positive but scan-negative are currently given systemic therapy or nothing. Whole-body MRI plus a lineage-appropriate PET tracer (PSMA, somatostatin receptor, FAP or fibroblast-directed imaging) detects lesions well below conventional CT thresholds, which would allow ablative treatment of true oligorecurrence and spare the rest systemic therapy.","asOf":"2026-09-08","links":[{"label":"Bottleneck evidence (Dormant cells and minimal residual disease): Tie et al., ctDNA analysis guiding adjuvant therapy in stage II colon cancer (NEJM 2022)","url":"https://doi.org/10.1056/NEJMoa2200075"}],"tags":[],"related":["idea-psma-pet-guided-mdt"],"cancers":["colorectal","breast-hr-positive","prostate"],"sections":[],"technologies":["whole-body-mri","psma-pet","fapi-pet","sbrt","mrd-testing","sstr-pet"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["oligometastatic","biochemical-recurrence"],"trials":[],"people":[],"bottlenecks":["b-dormancy-mrd","b-metastasis-biology"],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"hypothesis":"In ctDNA-positive, CT-negative patients, whole-body MRI plus a targeted PET tracer localises disease in at least 40%, and ablation of all detected lesions clears ctDNA in half of those patients.","rationale":"PSMA PET already redefined biochemical recurrence in prostate cancer by finding lesions in patients previously classed as non-localisable, and metastasis-directed therapy in that setting delays systemic treatment.","test":"A prospective imaging cohort in ctDNA-positive colorectal and breast cancer measuring localisation rate; if the rate exceeds a pre-set threshold, proceed to a randomised trial of ablation plus systemic therapy versus systemic therapy alone.","maturity":"early-clinical","actor":"clinic","cost":"medium","horizonYears":4},"route":"/ideas/idea-bio2-localise-the-mrd/","neighbours":{"idea":[{"id":"idea-psma-pet-guided-mdt","kind":"idea","name":"PSMA-PET-guided metastasis-directed therapy as a curative strategy in oligorecurrent prostate cancer","route":"/ideas/idea-psma-pet-guided-mdt/"}],"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"}],"technology":[{"id":"fapi-pet","kind":"technology","name":"FAPI PET","route":"/technologies/fapi-pet/"},{"id":"mrd-testing","kind":"technology","name":"MRD / molecular residual disease testing","route":"/technologies/mrd-testing/"},{"id":"psma-pet","kind":"technology","name":"PSMA PET","route":"/technologies/psma-pet/"},{"id":"sbrt","kind":"technology","name":"SBRT / SABR (stereotactic radiotherapy)","route":"/technologies/sbrt/"},{"id":"sstr-pet","kind":"technology","name":"Somatostatin receptor PET (68Ga/64Cu-DOTATATE)","route":"/technologies/sstr-pet/"},{"id":"whole-body-mri","kind":"technology","name":"Whole-body MRI","route":"/technologies/whole-body-mri/"}],"term":[{"id":"biochemical-recurrence","kind":"term","name":"Biochemical recurrence (BCR)","route":"/terms/biochemical-recurrence/"},{"id":"oligometastatic","kind":"term","name":"Oligometastatic disease","route":"/terms/oligometastatic/"}],"bottleneck":[{"id":"b-dormancy-mrd","kind":"bottleneck","name":"Dormant cells and minimal residual disease","route":"/bottlenecks/b-dormancy-mrd/"},{"id":"b-metastasis-biology","kind":"bottleneck","name":"Metastasis is understood least and studied last","route":"/bottlenecks/b-metastasis-biology/"}]}}