Interventional management of cancer pain

Epidural and Intrathecal Drug Delivery in Rats and Mice for Experimental Research: Fundamental Concepts, Techniques, Precaution, and Application

Epidural and intrathecal routes are the most effective drug administration methods for pain management in clinical and experimental medicine to achieve quick results, reduce required drug dosages, and overcome the adverse effects associated with the oral and parenteral routes. Beyond pain management with analgesics, the intrathecal route is more widely used for stem cell therapy, gene therapy, insulin delivery, protein therapy, and drug therapy with agonist, antagonist, or antibiotic drugs in experimental medicine. However, clear information regarding intrathecal and epidural drug delivery in rats and mice is lacking, despite differences from human medicine in terms of anatomical space and proximity to the route of entry. In this study, we discussed and compared the anatomical locations of the epidural and intrathecal spaces, cerebrospinal fluid volume, dorsal root ganglion, techniques and challenges of epidural and intrathecal injections, dosage and volume of drugs, needle and catheter sizes, and the purpose and applications of these two routes in different disease models in rats and mice. We also described intrathecal injection in relation to the dorsal root ganglion. The accumulated information about the epidural and intrathecal delivery routes could contribute to better safety, quality, and reliability in experimental research.

Neuroimaging Assessment of Pain

Pain is an unpleasant sensory and emotional experience. Understanding the neural mechanisms of acute and chronic pain and the brain changes affecting pain factors is important for finding pain treatment methods. The emergence and progress of non-invasive neuroimaging technology can help us better understand pain at the neural level. Recent developments in identifying brain-based biomarkers of pain through advances in advanced imaging can provide some foundations for predicting and detecting pain. For example, a neurologic pain signature (involving brain regions that receive nociceptive afferents) and a stimulus intensity-independent pain signature (involving brain regions that do not show increased activity in proportion to noxious stimulus intensity) were developed based on multivariate modeling to identify processes related to the pain experience. However, an accurate and comprehensive review of common neuroimaging techniques for evaluating pain is lacking. This paper reviews the mechanism, clinical application, reliability, strengths, and limitations of common neuroimaging techniques for assessing pain to promote our further understanding of pain.

Interventional pain management in patients with cancer-related pain

Invasive interventional procedures for managing pain in cancer patients are often underutilized following the popularization of the WHO analgesic ladder. The procedures that were successfully used until then were relegated away from mainstream palliative care practice, with the advent of newer opioids and adjuvants. Even though nerve blocks, intrathecal pumps and spinal cord stimulation were reintroduced as the fourth step of the WHO ladder, often referrals for these procedures are too late to produce a meaningful effect on quality of life. At this point most patients have advanced disease and are requiring end of life care. Additionally, it is becoming evident that at least 10% of patients do not achieve good quality analgesia with oral opioids and are often troubled by unacceptable side effects. There is an increasing public awareness of the problems with long-term opioid therapy and some of these patients would certainly benefit from invasive procedures to alleviate their pain and improve their quality of life. Improving life quality and expectancy with better treatment options and increasing number of cancer survivors should be heralding a change and hence neurolytic procedures are to be used only in patients with limited life expectancy. ITDDs, neuromodulation and ever-increasing use of procedures routinely used in treating chronic nonmalignant pain would be the mainstay of interventional management until AI and nanotechnology would open doors for novel treatment options. Interventions should not be used as a last resort after multiple failed attempts at opioid therapy, but as an integral part of a management strategy including medical management, psychological and emotional welfare, and supportive care of the patient in a holistic manner. The curriculum of specialists should include appropriate training to safely perform and produce better quality evidence to validate the efficacy and safety of these challenging procedures.

Approaches and Best Practices for Managing Cancer Pain within the Constraints of the COVID-19 Pandemic in India

Novel corona virus disease 2019 (COVID-19) is an ongoing pandemic that has impacted the entire world. The Indian government has responded strongly and very stringently to the crisis, through a nationwide lockdown. The health-care (HC) systems in the country are striving hard to maintain equitable care across illness spectra, while responding the emergencies imposed by the COVID-19 crisis. Under these circumstances, guidelines for managing several diseases including that for cancer care have been modified. As modified guidelines for cancer care have their focus on disease management, cancer pain management and maintaining continuity of care for patients with advanced progressive disease have taken a backseat in the available cancer care guidelines. This article describes the challenges, approaches to solutions with evidence-based practices that can be utilized to ensure competent management of cancer pain during the COVID-19 pandemic in India. It provides an overview of adapting to telehealth consultations for identification, evaluation and management of cancer pain, safe and rational use of analgesics and adjuvant drugs, recognizing and responding to holistic care needs and addressing the total pain, ensuring continuity of pain management, and strategies when complying with narcotic drug regulations, while ensuring safety of patients and HC providers.

Successful Treatment of Refractory Cancer Pain and Depression with Continuous Intrathecal Administration of Dexmedetomidine and Morphine: A Case Report

Patients who have refractory cancer pain suffer both physically and psychologically. Cancer pain management has improved over the past few decades. However, the treatment of refractory cancer pain is still challenging all over the world. Intraspinal analgesia has become an effective strategy to treat refractory pain in patients with cancer. In this report, we present a patient receiving a large dose of intrathecal opioids for refractory cancer pain, and who is also afflicted with pain-induced depression. Dexmedetomidine (DEX) was used as part of a multimodal analgesic regimen that successfully alleviated both the patient's pain and depression. An intrathecal infusion of DEX may serve as an adjuvant drug in the treatment of cancer pain and pain-related depression.

Curing Opioid Toxicity with Intrathecal Targeted Drug Delivery

Pain is one of the most feared symptoms that concern cancer patients and their families. Despite well-established guidelines set forth by the World Health Organization (WHO) on the treatment of cancer pain, nearly half of cancer patients report poorly controlled pain. One of the most serious side effects of systemic oral opioid use is neurotoxicity, which is characterized by altered mental status and systemic neurologic impairments. Treatment strategies are supportive in nature and focused on reducing or changing the offending opioid and correcting any metabolic deficiencies. Herein, we discuss a case of opioid-induced neurotoxicity treated with intrathecal targeted drug delivery (TDD). The timing and implementation of advanced therapies such as intrathecal TDD is not well delineated. More importantly, patients and their oncologic providers are often unaware of this useful tool in treating challenging cancer-associated pain and significantly minimizing systemic opioid side effects. To ensure that patients have comprehensive oncologic care, best-practice guidelines suggest involvement of an interdisciplinary team and coordinated care. Early referral to a pain and palliative specialist may allow for improved patient outcomes and removal of unnecessary barriers to optimal patient care.

Cancer pain: where are we now?

Increasing numbers of those living with and beyond cancer presents a clinical challenge for pain specialists. A large proportion of these patients experience pain secondary to their disease or its treatment, impeding rehabilitation and significantly impacting upon their quality of life. The successful management of this pain presents a considerable challenge. This review aims to outline current concepts and treatment options, while considering nuances within pain assessment and the use of large-scale data to help guide further advances.

Use of a Tilting Orthopedic Fracture Table to Facilitate Proper Patient Positioning During Intrathecal Neurolysis With Hyperbaric Phenol: A Case Report

We describe the case of a 41-year-old woman with metastatic cervical cancer and a large mass eroding into the pelvis and left lumbosacral plexus. The patient had intractable left lower extremity pain refractory to standard therapies, and she elected to undergo intrathecal neurolysis. A diagnostic intrathecal block was performed at the T11-12 interspace followed by intrathecal neurolysis with 6% phenol in glycerin on a subsequent date. During both procedures, we used a tilting radiolucent orthopedic fracture table to maintain strict left lateral-supine positioning. A tilting orthopedic fracture table may be a valuable adjunct to ensure positional stability during intrathecal neurolysis.

Image-guided cryoablation for the treatment of painful musculoskeletal metastatic disease: a single-center experience

PURPOSE

The role of image-guided thermal ablation techniques for the nonoperative local management of painful osseous metastatic disease has expanded during recent years, and several advantages of cryoablation in this setting have emerged. The purpose of this study is to retrospectively evaluate and report a single-center experience of CT-guided percutaneous cryoablation in the setting of painful musculoskeletal metastatic disease.

METHODS

This study was approved by the institutional review board and is compliant with the Health Insurance Portability and Accountability Act. Electronic medical records of all patients who underwent percutaneous image-guided palliative cryoablation at our institution were reviewed (n = 61). An intent-to-treat analysis was performed. Records were reviewed for demographic data and anatomical data, primary tumor type, procedure details, and outcome-including change in analgesic requirements (expressed as morphine equivalent dosages), pain scores (utilizing the clinically implemented visual analog scale), subsequent therapies (including radiation and/or surgery), and complications during the 24 h following the procedure and at 3 months. Patients were excluded (n = 7) if data were not retrospectively identifiable at the defined time points.

RESULTS

Fifty-four tumors were ablated in 50 patients. There were statistically significant decreases in the median VAS score and narcotic usage at both 24 h and 3 months (p < 0.000). Six patients (11%) incurred complications related to their therapy. Two patients had no relief at 24 h, of which both reported worsened pain at 3 months. One patient had initial relief but symptom recurrence at 3 months. Four patients went on to have radiation therapy of the ablation site at some point following the procedure.

CONCLUSIONS

CT-guided cryoablation is a safe, effective, reproducible procedural option for the nonoperative local treatment of painful musculoskeletal metastatic disease.

Neuropathic cancer pain: What we are dealing with? How to manage it?

Cancer pain is a serious health problem, and imposes a great burden on the lives of patients and their families. Pain can be associated with delay in treatment, denial of treatment, or failure of treatment. If the pain is not treated properly it may impair the quality of life. Neuropathic cancer pain (NCP) is one of the most complex phenomena among cancer pain syndromes. NCP may result from direct damage to nerves due to acute diagnostic/therapeutic interventions. Chronic NCP is the result of treatment complications or malignancy itself. Although the reason for pain is different in NCP and noncancer neuropathic pain, the pathophysiologic mechanisms are similar. Data regarding neuropathic pain are primarily obtained from neuropathic pain studies. Evidence pertaining to NCP is limited. NCP due to chemotherapeutic toxicity is a major problem for physicians. In the past two decades, there have been efforts to standardize NCP treatment in order to provide better medical service. Opioids are the mainstay of cancer pain treatment; however, a new group of therapeutics called coanalgesic drugs has been introduced to pain treatment. These coanalgesics include gabapentinoids (gabapentin, pregabalin), antidepressants (tricyclic antidepressants, duloxetine, and venlafaxine), corticosteroids, bisphosphonates, N-methyl-D-aspartate antagonists, and cannabinoids. Pain can be encountered throughout every step of cancer treatment, and thus all practicing oncologists must be capable of assessing pain, know the possible underlying pathophysiology, and manage it appropriately. The purpose of this review is to discuss neuropathic pain and NCP in detail, the relevance of this topic, clinical features, possible pathology, and treatments of NCP.

Osteolysis and pain due to experimental bone metastases are improved by treatment with rapamycin

In advanced breast cancer, bone metastases occur in 70 % of patients. Managing the devastating pain associated with the disease is difficult. Rapamycin is an immunomodulatory drug that targets the mammalian target of rapamycin pathway. Rapamycin has been shown to decrease osteolysis associated with metastatic breast cancer in pre-clinical models and to reduce pain in inflammatory and neuropathic models. The aim of this study was to evaluate the effectiveness of rapamycin in reducing pain associated with experimental osteolytic metastases. Bone cancer was induced by intra-tibial injections of murine mammary carcinoma cells (4T1) in immunocompetent BALB/c mice and treated intraperitoneally for up to 5 weeks with vehicle, rapamycin or pamidronate (a bisphosphonate currently used to reduce bone loss in bone cancer patients). The control group received intra-tibial injection with saline (sham) and was treated with vehicle intraperitoneally. Cancer-induced osteolysis was observed histologically and radiographically 2-3 weeks following cancer inoculation and gradually increased with time. Measures of evoked nociceptive behaviors including sensitivity to mechanical, thermal, and cold stimuli and spontaneous nociceptive behaviors (limping, guarding) were evaluated. Significant hypersensitivity to sensory stimuli developed in cancer-bearing mice compared to sham 3 weeks following inoculation. Rapamycin decreased or delayed the development of cancer-induced mechanical, heat, and cold hypersensitivity, while pamidronate reduced heat and cold hypersensitivity. Both rapamycin and pamidronate had a partial protective effect on the spontaneous nociceptive behaviors, limping and guarding. Our data suggest that rapamycin may have efficacy in the management of pain associated with metastatic breast cancer.

Racial and ethnic disparities in palliative care

Racial and ethnic disparities in health care access and quality are well documented for some minority groups. However, compared to other areas of health care, such as disease prevention, early detection, and curative care, research in disparities in palliative care is limited. Given the rapidly growing population of minority older adults, many of whom will face advanced serious illness, the availability of high-quality palliative care that meets the varied needs of older adults of all races and ethnicities is a priority. This paper reviews existing data on racial and ethnic disparities in use of and quality of palliative care and outlines priorities for future research.

Ultrasound-guided infraorbital nerve pulsed radiofrequency treatment for intractable postherpetic neuralgia - a case report -

A 60-year-old man presented with pain on the left cheek and lateral nose. The patient had been diagnosed with facial herpes zoster in the left V2 area 6 months previously. Medical treatment was prescribed for 6 months but it had little effect. We blocked the left infraorbital nerve under ultrasound guidance, but pain relief was short term. Therefore, we performed pulsed radiofrequency treatment on the left infraorbital nerve under ultrasound guidance. Six months after the procedure, the reduction of pain was still maintained, and there was no need for further management.