OBJECTIVE: To develop a technique for the evaluation of tumor perfusion prior to and during chemo- and radiation therapy.METHODS: Using the [(15)O]water autoradiographic technique and positron emission tomography (PET), perfusion in solid cervical tumors was investigated in a series of women prior to and during radiation therapy for cervical cancer. A 60-second summed image was used with the arterial blood curve to create a parametric image. The parametric images were registered to sagittal magnetic resonance (MR) images. Regions drawn on the MR images encompassing the tumor were transferred to the corresponding co-registered PET images.RESULTS: All tumors were easily visualized by both imaging modalities and tissue heterogeneity could be evaluated. Mean pre- and during therapy flow values averaged 41.5 +/- 11.9 and 48.2 +/- 7.2 mL/min/100 g tumor, respectively.CONCLUSIONS: Perfusion status of solid tumors, an assumed predictor of response potential, can be assessed using PET and the [(15)O]water technique.