ESTRO 2024 - Abstract Book

S1128

Clinical - Haematology

ESTRO 2024

137

Poster Discussion

Role of radiotherapy in the management of PET negative early Hodgkin's lymphoma : A real life study

Sabrina Aziez 1 , Laurent Quero 1 , Pauline Brince 2 , Laetitia Vercellino 3 , Sophie Guillerm 1 , Claire Meynard 1 , Catarina Cristinelli 2 , Catherine Thieblemont 1 , Christophe Hennequin 1 1 Hopital Saint Louis, Radiation Oncology, Paris, France. 2 Hopital Saint Louis, Hematology Oncology, Paris, France. 3 Hopital Saint Louis, Nuclear Medecine, Paris, France

Purpose/Objective:

This retrospective study aims to evaluate the impact of radiotherapy (RT) in patients with a good-response after chemotherapy (assessed by an intermediate 18-FDG-PET-scan with a Deauville score 1-3) in real life to confirm that RT could be omitted in those patients.

Material/Methods:

Patients treated for localized Hodgkin’s lymphoma (HL) between 2009 and 2019 with induction chemotherapy (CT) and with a good-response (Deauville 1-3) were included. Conformal radiotherapy was delivered or not according to physician preference. A dose of 20-30 Gy was prescribed using a technique of involved fields or involved nodes. End-points included progression-free (PFS) and overall survivals (OS) and late toxicity.

Results:

Three hundred ten patients were included. After chemotherapy 191 patients (62%) received a radiation therapy (Group 2) and 119 patients (38%) did not (Group 1). Median follow-up was 73 months (50-91 months). In the entire cohort, the 7 years PFS rate was 89.4% (IC95%: 85.5%; 93.4%). In Group 1, it was 81.5% (IC95% : 74.1%; 89.7%) versus 94.1% (IC95% : 90.2%; 98.3%) in Group 2 (p=<0.001 ). In multivariate analysis, the factors associated with a longer PFS were radiation therapy (0.012) and women gender (p=0.013).In the entire cohort, the 7 years OS rate was 96.8% (IC95% : 94.1%; 99.6%). In Group 1, it was 95.1% (IC95% : 89.2%; 100.0%) versus 97.9% (IC95% : 95.6%; 100.0%) in Group 2 (p=0.55). In univariate analysis, the only factor associated with a longer OS was the EORTC stage (p=0.031). We observed 7 secondary cancers, 3 in group 1 and 4 in group 2.

Conclusion:

This study shows that, in good-responders to chemotherapy, RT improved PFS but not OS. Modern techniques offer a low rate of late toxicity. This study confirms the results of randomized trials: in this setting, complementary RT must be discussed case by case to avoid relapses, according to initial prognostic factors, response to CT and potential toxicity of RT.