{"entity":{"id":"pet-adapted-therapy","kind":"technology","name":"PET-adapted (response-adapted) therapy","aka":[],"tldr":"Scan after two cycles of chemotherapy; if the tumour has gone dark, give less treatment, and if not, give more. Hodgkin lymphoma pioneered this.","summary":"Interim FDG-PET after cycle 2 (PET2) scored on the Deauville scale steers escalation or de-escalation: RATHL (omit bleomycin if PET2-negative, no loss of efficacy), HD18 (shorten escalated BEACOPP), HD16/HD17 and RAPID (omit radiotherapy in early stage if PET-negative, at a small PFS cost), and HD21/S1826 (PET-guided consolidation). Being extended to DLBCL and to ctDNA-adapted designs.","status":"standard-of-care","asOf":"2026-09-07","links":[{"label":"ClinicalTrials.gov NCT05675410: AHOD2131 (COG / NCTN)","url":"https://clinicaltrials.gov/study/NCT05675410"},{"label":"ClinicalTrials.gov NCT02661503: GHSG HD21","url":"https://clinicaltrials.gov/study/NCT02661503"}],"tags":[],"related":[],"indications":["dlbcl"],"sections":[],"technologies":["fdg-pet","pet-ct"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"principle":"FDG-PET measures metabolic response early; Deauville ≥4 at PET2 predicts failure, allowing therapy to be tailored before completion.","strengths":["Spares most patients bleomycin, radiation or intensified chemotherapy","Identifies the minority who need escalation"],"limitations":["Interim PET has imperfect positive predictive value (many PET2-positive patients are cured anyway)","Omitting radiotherapy trades a few percent PFS for late-toxicity avoidance"],"since":2016},"route":"/technologies/pet-adapted-therapy/","neighbours":{"indication":[{"id":"dlbcl","kind":"indication","name":"Diffuse large B-cell lymphoma","route":"/indications/dlbcl/"}],"technology":[{"id":"fdg-pet","kind":"technology","name":"FDG PET","route":"/technologies/fdg-pet/"},{"id":"pet-ct","kind":"technology","name":"PET/CT","route":"/technologies/pet-ct/"},{"id":"quantitative-imaging-biomarkers","kind":"technology","name":"Quantitative imaging biomarkers (RECIST, PERCIST, SUV, ADC)","route":"/technologies/quantitative-imaging-biomarkers/"}],"trial":[{"id":"ahod2131","kind":"trial","name":"AHOD2131 (COG / NCTN)","route":"/trials/ahod2131/"},{"id":"hd21","kind":"trial","name":"GHSG HD21","route":"/trials/hd21/"},{"id":"ielsg37","kind":"trial","name":"IELSG37","route":"/trials/ielsg37/"},{"id":"rathl","kind":"trial","name":"RATHL","route":"/trials/rathl/"}],"pairing":[{"id":"fdg-pet-response-adapted-therapy","kind":"pairing","name":"FDG PET then response-adapted chemotherapy","route":"/pairings/fdg-pet-response-adapted-therapy/"}]}}