The consistent provision of effective pain relief with minimal side effects is a major therapeutic goal in cancer therapy. However, it often remains an elusive goal in patients, particularly in children, undergoing repeated oncologic procedures such as lumbar puncture and bone marrow aspiration. Pharmacologic techniques of sedation and analgesia are utilized in most clinical settings, but their widespread use is limited by associated economic costs and side effects (e.g., safety risk, discomfort, and inconvenience). Alternative and complementary, non-pharmacologic analgesic techniques have been adopted in some cancer settings, but their mechanisms, efficacy, and specific indications have been incompletely investigated. Based on the general principal of cognitive distraction, immersive virtual reality (VR) is an innovative non-pharmacologic analgesic technique. Our research group has demonstrated its preliminary efficacy in non-cancer settings of acute procedural pain in adults and children, and is exploring the mechanisms and determinants of its analgesic effects. For example, analgesic efficacy appears dependent on the degree of 'presence' (or immersion) the user feels in the virtual world, a sensation that is strongly influenced by the user's interaction with, and movement within the environment. In the current proposal, we shall build on this knowledge and focus on the application of VR analgesia to procedural cancer pain in a series of preclinical studies. The broad, long-term objectives of this project are: (1) to design and fabricate VR hardware and software that incorporate multisensory input to maximize user 'presence' in the virtual environment (and hence analgesia), in subjects in whom body position is fixed (e.g., for lumbar puncture) and whose movement or motion is severely restricted (i.e., 'Movement-Restricted Virtual Reality' -- MRVR); (2) to assess the analgesic efficacy and side effects of MRVR relative to standard clinical VR (where motion is tolerated and encouraged) and to 2-D video distraction (a currently available distraction therapy) in adult and adolescent subjects experiencing controlled, analog (thermal) pain; and (3) to collect and interpret these preliminary data in order to design future controlled clinical trials of MRVR in adults and children during painful oncologic procedures.
