LOS ANGELESA retrospective study indicates that 18F-fluorodeoxyglu-cose
(FDG)-PET may be a good tool for predicting osteosarcoma patients’ response
to chemotherapy, said Christiane Franzius, MD, and colleagues from the
Department of Nuclear Medicine, University of Munster, Germany.
Dr. Franzius presented the results at the 49th Annual Meeting of the
Society of Nuclear Medicine (abstract 128).
In the study, the researchers monitored FDG uptake in 29 patients with
primary osteosarcoma (ages 5 to 41) before treatment. FDG uptake was
quantified as high or low using average and maximum tumor/nontumor ratios
(T/NTav, T/NTmax). The patients then received chemotherapy and underwent
surgery of their primary tumor site.
At a median of 28 months after treatment (range, 7 to 72 months), the
patients with higher initial FDG uptake in their tumor had a poorer response
to treatment, measured histologically, and a poorer prognosis.
During follow-up, nine patients relapsed and six died of the disease. Both
overall and event-free survival were significantly better in patients with
low FDG T/NTmax values (less than the median) than in those with high FDG T/NTmax
values (greater than or equal to the median).
"The prognosis for a patient with osteosarcoma is always dependent on the
therapy they undergo," Dr. Franzius said. "PET identifies patients at first
diagnosis of the disease who may have a poor prognosis with the therapy
usually prescribed. These patients can then be treated more aggressively. In
additional studies, we hope to determine whether such therapy intensification
actually improves outcomes for patients identified at diagnosis with high FDG
uptake on PET."
In an interview with ONI, Dr. Franzius said that the researchers plan to
study a large group of patients with osteosarcoma prospectively to confirm
the results of the current study.