Radiation-Free Therapy for the Initial treatment of Good prognosis early non-bulky HL, defined by a low Metabolic Tumor Volume and a negative interim PET after 2 chemotherapy cycles- RAFTING

Description of the study: Main objective of the trail is to explore the efficacy, in terms of 3-Y PFS of chemotherapy alone in low-risk early-stage I-IIA HL patients, defined by both a low MTV and a negative interim PET after 2 courses of ABVD.

Secondary objectives of the trail are those as listed below:

- to explore the efficacy in terms of 3-Y PFS, of tipple association (chemotherapy +INRT+ NivlumabNivolumab) in high-risk early-stage (I-IIA) HL (eHL), defined either by a positive PET-2 or a high baseline MTV or both

- to explore the efficacy in terms of 3-Y freedom from 2nd treatment failure (3-Y FF2TF) of chemotherapy followed by INRT “on demand” plus Nivolumab maintenance in patients relapsing with the pattern of “limited relapse” (see below) for the entire group (relapsed and non-relapsed) of low-risk patients (with low MTV and negative PET-2)

-to explore the safety in terms of 3-Y OS of a treatment with chemotherapy alone in low-risk early-stage (I-IIA) HL patients, defined by a low Metabolic Tumor Volume negative interim PET after 2 ABVD courses

-to evaluate the ability of cell-free DNA (cfDNA) assay to detect an impending relapse during follow-up in low-risk patients treated with chemotherapy alone.