The Impact of PSMA PET/CT Imaging in Prostate Cancer Radiation Treatment.

Imaging of prostate cancer is rapidly evolving with the introduction of the novel prostate-specific membrane antigen (PSMA)-targeted PET imaging tool for managing recurrent prostate cancer. One immediate impact of PSMA PET is the identification of residual or recurrent lesions that are amenable to external beam radiotherapy. Radiotherapy is used as a definitive curative treatment option for patients with localized prostate cancer alone or in combination therapy. In the setting of biochemical failure after radical prostatectomy, salvage radiation is a potential curative option, and the application of metastasis-directed radiotherapy in the setting of oligometastatic prostate cancer is currently being studied. To maximize the chances of curative therapy, the irradiated tumor volumes should completely encompass the actual extent of disease. Thus, an accurate estimation of the location and delineation of disease targets is critical for radiotherapy planning. The integration of PSMA PET imaging into the routine evaluation of prostate cancer has markedly improved sensitivity and specificity for recurrent disease, even at very low PSA values, which may enable further tailored radiation treatment plans, and help reduce the risk of radiation to adjacent normal tissues. However, while the introduction of PSMA PET will likely change behavior regarding earlier application of radiotherapy, the long-term impact of PSMA PET on patient outcomes is yet to be determined. The aim of the review is to give an overview of the use of PSMA-PET/CT imaging in the setting of radiation therapy for prostate cancer.