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

Objective(s): this study evaluates the utility of interim 18f-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<0.001). overall, patients with negative ipet had substantially better 3-year pfs than those with positive ipet (93.6% vs. 40.9%, p<0.0001). the predictive performance of ipet for treatment outcomes showed a sensitivity of 72.3%, specificity 89.0%, ppv 59.0%, npv 93.6%, and overall accuracy 86.0% (95% ci 0.78-0.91). diagnostic accuracy remained high across subgroups, ranging from 84.0% in early-stage disease to 89.5% in advanced-stage, and was highest in favorable early-stage (90.8%) and low-risk advanced-stage (93.7%) patients. in multivariate analysis, ipet was identified as an independent predictor of pfs (p<0.05).conclusion: in a real-world vietnamese cohort with hodgkin lymphoma, interim pet/ct guided by deauville scoring after two cycles of abvd chemotherapy showed strong predictive value for treatment response. the results advocate for broader integration of nccn-consistent risk-adapted strategies in southeast asia.