Real-World Outcomes of PET-Adapted Treatment for Classic Hodgkin's Lymphoma: A Study From a Single Tertiary Care Center.

Background  Classic Hodgkin's lymphoma (CHL) is frequently treated using a positron emission tomography (PET)-directed approach, as demonstrated in the Response-Adapted Therapy for Hodgkin Lymphoma (RATHL) trial. This study aimed to compare real-world patient outcomes with those reported in the RATHL trial for individuals with advanced-stage disease. Methods This retrospective study included 169 adult patients aged 18 years and older (range 20-66 years). Only patients who received treatment and subsequent follow-up at our institution were included in this study. Results The study population had a male-to-female ratio of 1.86:1, with a median age of 30 years. B symptoms were present in 119 patients (70.4%), while bulky disease (>33% of the transthoracic diameter or >10 cm elsewhere) was observed in 55 patients (32.5%). More than half (57.4%) had stage IV disease at diagnosis, and the median follow-up time was 4.79 years. The three-year overall survival rate was 92.3%, and the progression-free survival rate was 76.9%. Among the 49 patients in the interim PET-positive group, the three-year overall survival and progression-free survival rates were 83.7% and 57.1%, respectively. Of these, 17 (34.7%) received escalated therapy with bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP), while 32 (65.7%) continued with doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) or standard BEACOPP. No significant survival difference was observed between these treatment groups. In the interim PET-negative group of 104 patients, 84 (80.8%) received ABVD, while 20 (19.2%) received doxorubicin, vinblastine, and dacarbazine (AVD). Again, no significant difference in survival was noted between these two groups. When comparing the interim PET-positive cohort to the RATHL trial, the three-year overall survival rates were 83.7% versus 87.8% (p = 0.45), and the progression-free survival rates were 57.1% versus 67.5% (p = 0.17), with no statistically significant difference. Conclusion This study highlights excellent real-world outcomes for treating CHL using a PET-directed approach similar to the RATHL trial. However, despite PET-guided therapy, interim PET positivity remained associated with significantly lower overall survival and progression-free survival rates. De-escalation to AVD in the interim PET-negative group did not negatively affect survival outcomes. ABVD remains a viable treatment option for PET-positive patients with good tolerance, strong response, or near-complete remission with single-site residual disease, without compromising survival.