PET scans are frequently used in the medical community and oncology. Today PET imaging is used in combination with computerized axial tomography for more accurate results. PET has been adopted in the treatment of lymphomas, where it’s often incorporated in treatment for Hodgkin’s and non-Hodgkin’s lymphoma.
PET scans are used in staging and treating lymphomas that have the potential for a cure, such as large cell and aggressive lymphomas and classical Hodgkin’s lymphoma. They offer enhanced sensitivity and convenience and can detect disease in normal-sized lymph nodes to allow effective treatment.
PET scans have helped to change treatment approaches. Other conventional imaging processes have not been able to identify disease in bulky masses with some residual mass or scar, forcing them to be irradiated unnecessarily. But now PET scanning has engendered the rethinking of such approaches when there is no apparent disease activity.
Today, a negative PET scan after completing treatment is essential for a complete remission. Minimal relapses occur in small percentages. Data also shows that determining a response early after a few chemotherapy cycles can help predict the outcome for large cell lymphoma and classical Hodgkin’s lymphoma that data obtained at the end of the treatment. This has led to the initiation of clinical trials to find out if changing therapy early after a PET scan will be beneficial.
Data indicates that a positive PET scan taken during or after chemotherapy can predict a high probability of failed treatment. A positive PET scan can predict drug resistance.
During the early interim negative PET scan, treatment can be shortened by giving patients four to five cycles instead of the usual six.
The role of PET imaging in low-grade lymphoma is not very clear. The standard uptake value scores for low-grade lymphoma are low, whereas those for aggressive or large cell lymphoma are often higher. If a high standard uptake value in a node in low-grade lymphoma is found, it will prompt a biopsy to check for aggressive disease. This can help during the initial diagnosis when there may be multiple lymphoma pathology or later when there is suspicion of transformation.