Prognostic utility of interim 18F-FDG PET/CT after two cycles of ABVD in response assessment in Hodgkin's lymphoma patients: single-center preliminary experience.

Objectives: F-FDG PET/CT (iPET)-guided therapy in a Southeast Asian population, addressing gaps in region-specific data. Key outcomes included treatment response rates and progression-free survival (PFS) stratified by iPET results (Deauville score (DS) 1-3 vs. 4-5) across all clinical risk groups (including early-stage favorable/unfavorable and advanced-stage based on the International Prognostic Score (IPS)). Findings will inform optimal risk-adapted strategies in resource-aware settings. Methods: A prospective study was conducted of 100 patients with Hodgkin Lymphoma (HL) at the Vietnam National Cancer Hospital from March 2020 to March 2024. All patients underwent baseline clinical assessment and imaging (CT and/or PET/CT), followed by two cycles of ABVD chemotherapy. IPET was performed for early response assessment using Deauville scores (DS), with subsequent treatment adjusted according to NCCN guidelines. Results: A total of 100 patients with classical Hodgkin lymphoma (mean age: 32±13.8 years; range 9-73) were analyzed. Bulky disease and extranodal involvement were observed in 10.0% and 15.0% of cases, respectively. Early-stage disease (stage I-II) was present in 72.0%, and advanced-stage (stage III-IV) in 28.0%. After two cycles of ABVD, 78.0% of patients had a negative iPET result (DS 1-3), of whom 88.5% were DS 1, while 22.0% had a positive iPET result (DS 4-5), predominantly DS 4 (72.7%). In early-stage disease, the 3-year progression-free survival (PFS) was significantly higher in the favorable group than in the unfavorable group (95.7% vs. 81.2%, p=0.03). In advanced-stage disease, low-risk (IPS 0-3) patients achieved a 3-year PFS of 88.2%, whereas high-risk (IPS 4-7) patients had a markedly lower PFS of 42.9% (p