PET-CT Adapted Therapy After 3 Cycles of ABVD for All Stages of Hodgkin Lymphoma. Interim Analysis in 173 Patients
Authors: Pavlovsky Santiago , Pavlovsky Astrid , Fernandez Isolda , Pavlovsky Miguel , Prates Virginia , Zoppegno Lucia , Basquiera Ana Lisa , Cerutti Ider , Rodriguez Andrea , Milone Gustavo , Castano Vanesa , Rudoy Silvia , Sackmann Federico , Valles Lourdes , Lastiri Francisco 
Published: October 2019

Abstract
Abstract 1772

Background:
Hodgkin Lymphoma (HL) is the most curable type of Lymphoma with an overall survival at 5 years of 80%. ABVD can be considered as gold standard for first line treatment for all stages of HL. Dividing patients (pts.) in different prognostic groups has aimed to reduce chemo and radio toxicity in those patients with good prognosis. A negative PET-CT, either early during treatment of ABVD or after completion of it, has shown to be a powerful prognostic tool (Hutchings: Blood 2006; Gallamini: Haematologica 2006). Our cooperative group has an experience with 584 patients with HL in early or advanced stage treated with 3 or 6 cycles of ABVD plus involved field radiotherapy with a complete remission (CR) of 91% and an event free survival (EFS) and overall survival (OS) at 60 months of 79% and 95%.(S Pavlovsky, Clin Lymp My & Leuk, 2010).

Aims:
Test the efficacy of treatment to all stages of HL adjusted to PET-CT results after 3 cycles of ABVD. Evaluate the outcome of pts. who have a negative PET-CT after 3 cycles of ABVD and receive no further treatment. Intensify therapy only in pts. who have persistent hyper metabolic lesions in PET-CT after 3 cycles of ABVD.

Method:
Since October 2005, 198 newly diagnosed pts. with HL have been included in a prospective multicenter trial. Initially all patients received 3 cycles of ABVD. After the third cycle, pts. were evaluated with a PET-CT. Those pts. who achieved CR with a negative PET-CT, received no further treatment. Those with more than 50% of anatomic reduction of initial masses but persistent hyper metabolic lesions by PET-TC after 3 ABVD were considered in partial remission (PR) and completed 6 cycles of ABVD and radiotherapy (RT) on PET-CT positive areas. Those patients with less than PR after 3 cycles of ABVD received ESHAP and if CR, high doses of chemotherapy and an autologous stem cell transplant (ASCT). All patients were re-evaluated at the end of treatment. The median follow up is of 30 months (3-62).

Results:
One hundred and seventy three patients completed three cycles of ABVD followed by a PET-CT. The median age at diagnosis was 29 years. One hundred and thirty-six (79%) had localized stage (I-II) at diagnosis and 37 (21%) presented with advanced stage (III-IV). Of 155 pts. 77 (50%) pts had IPS 0–1, 66 (43%) had IPS 2–3 and 12 (8%) had IPS 4–5. Twenty six (17%) pts. had bulky disease at diagnosis. One hundred and thirty-seven (79%) pts. achieved CR with negative PET-CT after 3 cycles of ABVD. Thirty-six (21%) were PET-CT positive, of them 32 pts achieved PR and completed a total of 6 cycles of ABVD plus RT in hyper metabolic lesions. Twenty five achieved CR (72%), 5 persisted with PR and 2 died of progressive disease. Four pts showed progressive disease (PD) after 3 ABVD and received ESHAP and ASCT, 2 achieved and remained in CR, 1 is in PR and 1 died of progressive disease. Of 173 pts who completed treatment with ABVD × 3 cycles, ABVD × 6 cycles plus RT on PET-TC positive areas or ESHAP plus ASCT, 164 pts (95%) achieved CR. Of these 164 pts., 14 pts (8%) relapsed. The EFS and OS at 36 months is 83% and 97% respectively. Patients with early negative PET-TC have an event-free survival of 87% compared to 62% (P=0,001) for pts with early positive PET CT. The OS at 36 months was 100% versus 86% respectively (<0.001).

Conclusion:
Treating patients with ABVD, evaluating response after 3 cycles with PET-CT, and adapting further therapy, leads to a high rate of CR avoiding more aggressive chemotherapy and radiotherapy. Three courses of ABVD without RT are adequate in patients with early CR defined by negative PET-CT. In early positive PET-CT it is possible to intensify therapy improving the otherwise bad prognosis; more aggressive treatment might also be suitable. These results need to be confirmed by a larger group of patients and a longer follow-up.

Disclosures:
No relevant conflicts of interest to declare.