Involved field radiotherapy versus no further treatment in patients with clinical stages IA and IIA Hodgkin lymphoma (HL) and a negative PET scan after 3 cycles ABVD. Results of the UK NCRI RAPID trial
Session type: Poster / e-Poster / Silent Theatre session
In the RAPID trial PET response directed therapy was evaluated in early stage HL. Patients (pts) received 3 cycles ABVD followed by a PET scan. If the PET scan was ‘negative' (score 1 or 2 on 5 point scale) at central review, pts were randomised between IFRT and no further treatment (NFT). If ‘positive' (score 3, 4 or 5) pts had a 4th cycle ABVD and IFRT. This non-inferiority trial required 400 PET negative pts to be randomised for exclusion of a ≥7% difference in 3-year progression-free survival (PFS).
602 pts with previously untreated stages IA/IIA HL and no mediastinal bulk were registered 2003-2010. Following 3 cycles ABVD, 571 pts had a PET scan of which 426 (74.6%) were ‘negative'. 420 PET ‘negative' pts were randomised to receive IFRT (n=209) or NFT (n=211). 22/209 pts randomised to IFRT did not receive this because 16 pts declined after they became aware of the randomisation decision, 5 had died, 1 had pneumonia.
After median follow-up of 45.7 months, 384/420 (91.4%) PET negative pts are alive/progression-free, 29 (6.9%) are alive/progressed and 7 (1.7%) have died; combined 3-year PFS 92.2% and overall survival (OS) 98.3%. In the IFRT arm, 194 pts are alive/progression-free, 9 have progressed, and 6 have died. In the NFT arm 190 pts are alive/progression-free, 20 have progressed, and 1 has died. 3-year PFS is 93.8% (IFRT) versus 90.7% (NFT) and 3-year OS 97.0% (IFRT) versus 99.5% (NFT). For the 145 PET positive pts, 126 are alive/progression-free, 11 progressed, and 8 died to give a 3-year PFS of 85.9% and OS of 93.9%.
Pts with early stage HL and a negative PET after 3 cycles ABVD have an excellent prognosis without further treatment. This approach reduces treatment time/costs, improves tolerability and removes toxicity of radiotherapy from the PET negative population.