 Our interest in in situ tumor oxygenation relates to the clinical need to measure oxygen in tumors prior to therapy, to understand tumor oxygen dynamics over the course of therapy, and to assess the effectiveness of oxygen modulation therapy during treatment. Our interest in the postsurgical radiation field relates to the clinical need to understand whether the temporal dynamics of oxygen within the postsurgical radiation field has the potential to enhance the effectiveness of adjuvant therapies, and to understand how changes in short and long term oxygenation within the postsurgical radiation field may facilitate diminishment of late side effects from surgery andor radiotherapy. 