It is estimated that 10%-15% of patients with cancer-related pain do not achieve acceptable levels of pain relief even when oral or parenteral opioids are skillfully combined with conventional adjuvant analgesics and intractable pain occurs in up to 2% of advanced cancer patients. Painful conditions arising from tumor-nerve structure involvement, neuropathic pain, skin lesions, iatrogenic (chemo-and radiotherapy lesion), or ischemic pain are those most likely to require more aggressive treatment, such as the use of unconventional agents or interventional management approaches.