Use of (18F)FTC-146 PET_MRI for Characterizing Chronic Pain Phenotypes in Chronic Pain Patients with Spinal or Peripheral Nerve Origin

Chronic pain represents a significant and widespread problem affecting approximately one-fifth person of the global population. As reported by the Institute of Medicine in 2011, chronic pain impacts 116 million American adults, surpassing the combined prevalence of heart disease, cancer, and diabetes. The economic burden associated with chronic pain is staggering, with an estimated annual expenditure of $635 billion on medical management and lost productivity1. Chronic pain can interfere with a person's daily life and lead to depression, insomnia and anxiety which can make the chronic pain worse. Chronic pain has many forms and appears across the body. For this study we will focus on chronic pain with spinal or peripheral nerve origin.

Chronic pain in the spinal cord or peripheral nerves can be caused by neuropathic pain, which occurs when the nervous system is damaged or malfunctions. Tumors, specifically schwannomas, are known to cause neuropathic chronic pain in subjects. The chronic pain can also be caused by nociceptive pain which is a type of pain that occurs when body tissue is damaged by physical or chemical agents, such as trauma, surgery, or chemical burns.

Pain is common and debilitating in people with schwannomatosis: Pain is the defining feature of most forms of schwannomatosis. While neurologic deficits (e.g., weakness) are relatively rare, pain is extremely common. Pain correlates with greater disability, and pain-related interference in daily activities correlates with poorer quality of life.

In patients with schwannomatosis, due to the presence of multiple tumors and frequent non-tumorigenic sources of pain, identifying the pain-generating tumor(s) can be difficult. This is particularly true since there does not seem to be any correlation between tumor size or active tumor growth and pain. Furthermore, even when pain can be localized to a specific nerve distribution, the nerve in question often will have multiple tumors along its course.

Current clinical methods for diagnosing and localizing pain generators are inadequate, highlighting the urgent need for more objective molecular assays capable of identifying sites of enhanced nociceptive activity. This will facilitate better diagnosis and targeted therapy for the patient. Additionally, the limited number availability of analgesic options for chronic and neuropathic pain patients, coupled with significant adverse effects, underscores the critical need for safer and better-tolerated analgesics.