PET project.

Top Line: Can radiation be omitted in patients with early stage unfavorable Hodgkin lymphoma and a negative PET scan after chemo?

The Study: For a disease site whose data can sometimes make your head spin, the German Hodgkin Study Group has put together one of the most rational and methodical series of clinical trials to guide treatment for HL. Let’s go through the GHSG approach to early stage, unfavorable HL. In HD11, patients were randomized 1) to either 4 cycles of ABVD or 4 cycles of escalated BEACOPP and 2) either 20 Gy or 30 Gy of radiation. ABVDx4 + 30 Gy came out on top as reducing radiation dose (20 Gy) with ABVD negatively impacted freedom from treatment failure while eBEACOPP did not significantly improve FFTF (and it was more toxic). Subsequently, HD14 compared ABVDx4 + 30 Gy with a hybrid “2+2” regimen of eBEACOPPx2 + ABVDx2 + 30 Gy, but only patients under 60. It showed a significant 6.2% absolute improvement in PFS with the 2+2 regimen. So, now we come to HD17 where 2+2 + 30 Gy was compared to a PET-adaptive arm where radiation was omitted if the post-chemo PET was negative (Deauville 1-2). Most patients (66.5%) had a negative PET4 while 24.3% had Deauville 3 and 9.2% had Deauville 4. This is important, because Deauville 3 is sometimes considered “negative” depending on the algorithm you’re following. At 5 years, PFS was non-inferior with PET-adaptive therapy (95.1 vs. 97.3%). What’s more, these PFS rates were actually higher than those in the early stage, favorable trial, HD16. So, HD17 supports the PET-adaptive use of radiation following eBEACOPP and ABVD and a Deauville score of 1-2.

TBL: Among patients with early stage, unfavorable HL who receive the GHSG 2+2 regimen, ⅔ of patients may safely omit additional radiation after a negative (Deauville 1-2) PET. | Borchmann, Lancet Oncol 2021