Steve Cho MD, Presenter: Nothing to Disclose

Alin Chirindel, Abstract Co-Author: Nothing to Disclose

Jongho Kim MD, PhD, Abstract Co-Author: Nothing to Disclose

Lu Chen, Abstract Co-Author: Nothing to Disclose

Allen Buxton, Abstract Co-Author: Nothing to Disclose

Sandy Kessels, Abstract Co-Author: Nothing to Disclose

Jeffrey P. Leal BA, Abstract Co-Author: Nothing to Disclose

Kathleen M. McCarten MD, Abstract Co-Author: Nothing to Disclose

Suzanne L. Wolden MD, Abstract Co-Author: Nothing to Disclose

Cindy Schwartz, Abstract Co-Author: Nothing to Disclose

Debra Friedman, Abstract Co-Author: Nothing to Disclose

Kara Kelly, Abstract Co-Author: Nothing to Disclose

The purpose of this study was to assess the prognostic value of baseline tumor burden as determined by FDG PET-based parameters in pediatric HL.

We retrospectively analyzed multi-site FDG PET/CT images from patients enrolled on COG AHOD0031, a Phase III study for newly diagnosed intermediate-risk pediatric HL. A cohort of 90 patients was identified based on availability of high quality archived PET/CT scans amenable to quantitative analysis and a pre-determined selection process that ensured inclusion of patients representative of different chemotherapy response groups. Baseline PET images were analyzed by consensus of 2 readers blinded to clinical outcome data using MIMVistaTM software. PET standardized-uptake value (SUV) threshold values based on various absolute, liver, blood pool and tumor were assessed to derive PET parameters for total body nodal tumor burden including: average tumor SUV (SUVavg), metabolic tumor volume (MTV) and total tumor glycolytic activity (TGA). Event free survival (EFS) was the clinical endpoint of interest and analyzed by log-rank test and Cox proportional hazard model. Selected parameters were further assessed using receiver-operating-characteristic (ROC) analysis where the outcome was 2-year EFS.

Baseline FDG PET SUV derived MTV and TGA parameters were found to be highly predictive for EFS for a variety of thresholds (P<0.05). PET SUV threshold values found to be most predictive and reliable included: 1.5Lv + 2xliver standard deviation (1.5Lv+2SD), 2xmediastinal blood pool (2BP) and 20% maximal tumor SUV (TSUVmax). ROC area under the curve (AUC) for MTV using 1.5Lv+2SD, 2BP and TSUVmax threshold was 0.77, 0.84, and 0.79, respectively. Use of an “optimal cut-off” PET MTV value based on the ROC for 1.5Lv+2SD, 2BP and TSUVmax was able to separate EFS groups (P<0.005). Baseline tumor SUVavg was not found to be predictive for EFS.

Baseline FDG PET SUV derived total body tumor burden as represented by tumor volume (MTV) and total tumor glycolytic activity (TGA) is highly predictive of EFS in pediatric HL. These parameters need further validation for incorporation into HL prognostic stratification schemes.

Baseline pre-therapy FDG PET derived metabolic tumor volume may be a potentially useful tool for use as a prognostic parameter and for risk-stratification of HL patients.

Cho, S, Chirindel, A, Kim, J, Chen, L, Buxton, A, Kessels, S, Leal, J, McCarten, K, Wolden, S, Schwartz, C, Friedman, D, Kelly, K, FDG PET-based Parameters for Total Tumor Burden at Diagnosis are Highly Predictive for Outcome in Pediatric Hodgkin Lymphoma (HL): A COG AHOD0031 Retrospective Study.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14014814.html