Advancing Photodynamic Therapy: The Role of PET and SPECT in Imaging-Guided Theranostics.

Early cancer diagnosis is crucial for better treatment outcomes. Selecting the most effective therapy relies on accurate and specific diagnostic tools. Imaging plays a key role in evaluating new treatments, assessing disease progression, and monitoring tumor changes during therapy. It also aids in refining treatment strategies after completion. PDT shows significant promise in cancer treatment, using light-activated compounds to target cancer cells. Nuclear medicine techniques like PET and SPECT are particularly valuable for planning and monitoring PDT. Radiolabeled photosensitizers and clinically approved radiopharmaceuticals enable tracking of drug distribution and treatment effects, such as cell death, metabolism, and vascular damage. This review highlights the role of nuclear imaging in supporting PDT for cancer treatment.