Future Directions

The field of functional imaging in the care of lymphoma patients is evolving rapidly. FDG-PET scanning has the potential to contribute to care of lymphoma patients in many new ways. We must, however, carefully and systematically evaluate how best to incorporate this modality in order to use it optimally. Several areas of investigation must be pursued for this aim to be realized.

Many studies have investigated the prognostic importance and treatment implications for patients with specific stages of lymphoma. However, these studies were done using conventional staging techniques. While it is reasonable to imagine that improved staging would refine our ability to predict prognosis and appropriately choose treatment, we do not at this time know how disease detected by FDG-PET will impact on these factors. For example, will low-volume disease detected only by PET, changing a patient's stage from 2 to 3, portend a worse prognosis?

A critical question for investigation is the appropriate use of FDG-PET scanning in prediction of treatment outcome. Although a positive FDG-PET scan after therapy completion would appropriately lead to investigation of the positive lesion and further treatment if confirmed to be active disease, the use of scanning during treatment is less clear. More systematic studies evaluating the outcome of patients undergoing FDG-PET scans early in treatment must be performed to define the role of this strategy in guiding treatment. Patients with specific histologies should be evaluated under defined circumstances, at a defined time during treatment, in order to clarify whether this strategy can predict outcome with high enough accuracy to guide treatment changes. Furthermore, we do not know at this time what constitutes an appropriate treatment change. It is unclear if switching to another, possibly more intensive, treatment regimen will improve outcome in these patients, or instead whether a positive scan portends a poor prognosis whatever the treatment strategy. These questions can be answered only through well-designed, prospective clinical trials.

0 0

Post a comment