# PET-adapted (response-adapted) therapy

Source: https://nuclide.cc/technologies/pet-adapted-therapy/  
Nuclide record `pet-adapted-therapy` (Technology). Data CC BY-NC 4.0, attribute "Data from Nuclide (nuclide.cc)"; commercial use needs a licence.

## TL;DR

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.

## Fields

- Kind: Technology
- Status: standard-of-care
- Last checked: 2026-09-07
- Principle: FDG-PET measures metabolic response early; Deauville ≥4 at PET2 predicts failure, allowing therapy to be tailored before completion.
- Since: 2016
- 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

## Sources

- ClinicalTrials.gov NCT05675410: AHOD2131 (COG / NCTN): https://clinicaltrials.gov/study/NCT05675410
- ClinicalTrials.gov NCT02661503: GHSG HD21: https://clinicaltrials.gov/study/NCT02661503

## Connected records

- indications: [Diffuse large B-cell lymphoma](https://nuclide.cc/indications/dlbcl/)
- technologies: [FDG PET](https://nuclide.cc/technologies/fdg-pet/), [PET/CT](https://nuclide.cc/technologies/pet-ct/), [Quantitative imaging biomarkers (RECIST, PERCIST, SUV, ADC)](https://nuclide.cc/technologies/quantitative-imaging-biomarkers/)
- trials: [AHOD2131 (COG / NCTN)](https://nuclide.cc/trials/ahod2131/), [GHSG HD21](https://nuclide.cc/trials/hd21/), [IELSG37](https://nuclide.cc/trials/ielsg37/), [RATHL](https://nuclide.cc/trials/rathl/)
- pairings: [FDG PET then response-adapted chemotherapy](https://nuclide.cc/pairings/fdg-pet-response-adapted-therapy/)

---
JSON: https://nuclide.cc/api/v1/entities/pet-adapted-therapy.json