3619 - Outcome Prediction Using Quantitative Analysis of Advanced Metabolic PET Parameters in Early-Stage Hodgkin Lymphoma
Presenter(s)
K. M. Frechette1, J. P. Abeykoon2, U. Durani3, W. S. Harmsen4, M. K. Lee5, J. R. Young5, S. M. Ansell6, T. M. Habermann6, M. Iqbal7, A. Rosenthal8, B. S. Hoppe9, J. L. Peterson10, W. G. Rule11, R. Tao12, A. A. Chaudhuri13, J. F. Burlile13, D. K. Ebner14, R. O. Kowalchuk15, S. C. Lester13, and W. Breen13; 1Department of Radiation Oncology, Mayo Clinic Rochester, Rochester, MN, 2Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, 3Mayo Clinic, Department of Medicine, Division of Haematology, Rochester, MN, 4Mayo Clinic Rochester, Rochester, MN, 5Mayo Clinic, Rochester, MN, 6Division of Hematology, Mayo Clinic, Rochester, MN, 7Division of Hematology, Mayo Clinic, Jacksonville, FL, 8Division of Hematology, Mayo Clinic, Phoenix, AZ, 9Mayo Clinic, Jacksonville, FL, 10Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL, 11Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, 12Department of Radiation Oncology, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, 13Department of Radiation Oncology, Mayo Clinic, Rochester, MN, 14Rhode Island Hospital, Providence, RI, 15University of Virginia / Riverside Radiosurgery Center, Newport News, VA
Purpose/Objective(s): Clinical trials and real-world analyses have demonstrated a progression free survival benefit with combined modality therapy (CMT) compared to chemotherapy alone in early-stage classical Hodgkin lymphoma (cHL). However, it remains unclear which early-stage cHL patients would benefit from local radiotherapy (RT). Studies suggest quantitative positron emission tomography (PET) parameters obtained prior to treatment may be prognostic in early-stage cHL. We hypothesized that quantitative PET parameters using baseline and end of treatment (EOT) PET scans could predict local failures and thus inform who may benefit from adjuvant RT.
Materials/Methods: We reviewed records of early-stage (IA-IIB) cHL patients treated with CMT or chemotherapy only from 2010-2020 from our institution. Total metabolic tumor volume, total lesion glycolysis, maximum SUV (SUVmax) and mean SUV (SUVmean) were assessed on available baseline and EOT F18 fluorodeoxyglucose PET scans using MIM LesionID software. Relevant patient, disease and treatment characteristics were collected. Event free survival (EFS) (defined as any progression, relapse or death) and overall survival (OS) were analyzed.
Results: A total of 125 patients (n=68 received chemotherapy alone and n=57 received CMT) were included. Median follow up was 7.7 years. Bulky disease (>7 cm) was present in 32.4% and 36.8% of the chemotherapy and CMT groups, respectively (p=0.60). Median cycles of ABVD given in the CMT vs chemotherapy groups were 4 cycles (IQR 3-4) and 6 cycles (IQR 4-6), respectively. Baseline and EOT PET scans were available in 116 (93.0%) patients. There was one relapse in the CMT group (1.8%) and six relapses in the chemotherapy group (8.8%) (p=0.028). Mean time to relapse across the cohort was 19.6 months (range 12.7-31.7 months). Median SUVmax on baseline and EOT PET scans across the cohort was 12.8 (range 1.7-29.9) and 2.2 (range 1.3-18.4), respectively. Median SUVmean on baseline and EOT PET across the cohort was 3.7 (range 1.3-11.0) and 1.3 (range 0.6-3.8), respectively. Five-year EFS was lower in the chemotherapy group (73.0% vs 92.8% in the CMT group, p=0.0053) as was 5-year OS (92.5% vs 98.2% in the CMT group, p=0.21). Both SUVmax and SUVmean on EOT PET correlated with worse EFS (HR 1.16, p<0.001; HR 2.05, p=0.022) across the entire cohort. SUVmean on baseline PET was associated with worse OS (HR 1.36, p=0.022) and greater absolute decrease in SUVmean from baseline to EOT PET correlated with improved OS (HR 0.75, p=0.033) across the cohort. In the chemotherapy only group, bulky disease and SUVmax on EOT PET correlated with worse EFS (HR 2.87, p=0.022; HR 1.13, p=0.004).
Conclusion: For early-stage HL, quantitative PET parameters such as SUVmean and SUVmax on EOT PET appear to be correlated with EFS and may indicate which patients could benefit from local RT. SUVmean on baseline PET and smaller change in SUVmean from baseline to EOT PET also appear to be associated with worse survival in this cohort.