First use of 18F-labeled ML-10 PET to assess apoptosis change in a newly diagnosed glioblastoma multiforme patient before and early after therapy

Abstract

Objectives: The authors present the first use of the novel positron emission tomography (PET) apoptosis tracer 18F-labeled 2-(5-fluoro-pentyl)-2-methyl-malonic acid (18F-ML-10) for early-therapy response assessment of a newly diagnosed glioblastoma multiforme (GBM) patient. Case report: A 71-year-old male with a newly diagnosed GBM received 18F-ML-10 PET scans prior to therapy initiation (baseline) and after completing 3 weeks of whole-brain radiation therapy with concomitant temozolomide chemotherapy (early-therapy assessment, ETA). The baseline 18F-ML-10 PET scan showed increased tracer uptake at the site of the GBM, with highest activity toward the central portion of the tumor. At the ETA time point, a new distribution of tracer uptake was observed compared to baseline. Normalized pixel-by-pixel subtraction of baseline from ETA was used to quantify change in tracer distribution between 18F-ML-10 PET imaging time points. Results of this analysis showed reduction in 18F-ML-10 uptake at the site of greatest baseline uptake, but increased uptake around the periphery of the tumor at the early-therapy time point. Conclusion: The changing patterns of 18F-ML-10 uptake between baseline and ETA are suggestive for therapy-induced tumor cellular apoptosis. © 2014 The Authors.