Pre-treatment FDG-PET scans show promise for determining success of stem cell transplantation

This review aimed to determine the accuracy of  F-fluoro-2deoxy-D-glucose positron emission tomography (FDG-PET) scans at predicting the success of autologous (using the patient’s own stem cells) stem cell transplant (SCT). This study concluded that an FDG-PET scan before SCT may be of value in predicting the outcome of the SCT treatment. 

While Hodgkin lymphoma is generally considered curable, a certain number of patients every year will develop refractory (do not respond to treatment) or relapsed disease. These patients can be treated using second-line chemotherapy, but this will only cure around 50% of patients. It is therefore important to quickly identify if these treatments are working.

FDG-PET scans (a scan that uses a radioactive substance to image cancer cells) have been used to stage disease and to identify patients who are not responding to first-line treatments. Some studies have also shown the potential for the use of FDG-PET scans to predict the success of SCT.

This study looked at how accurately FDG-PET scans can predict the outcome of SCT.

14 previous studies were reviewed, including a total of 745 patients with recurrent or refractory Hodgkin lymphoma. The studies examined whether a pre-transplant FDG-PET scan predicted the treatment success of SCT. A positive FDG-PET scan indicates the presence of remaining cancer cells. A negative FDG-PET scan indicates that cancer cells are undetectable or absent.

The 2-5 year overall survival (OS, time from treatment until death from any cause) of patients who had a positive FDG-PET was between 17 and 77%. The OS for patients who had a negative FDG-PET was between 78 and 100%.

FDG-PET scans predicted 67.2% of patients with a positive scan who had a treatment failure. The scans predicted 70.7% of patients with a negative scan who were treated successfully. 

This study concluded that the results of a FDG-PET scan may be a good predictor of treatment outcome for patients receiving autologous stem cell transplantation.

The review notes that a large portion of patients with positive FDG-PET scans are treated successfully, and some patients with a negative FDG-PET scan may experience a relapse.