Considerations for the Use of Dorsal Column Stimulation for Lumbosacral Radiation Neuritis of the Nerve Root in the Spine Tumor Patient (A Case Series)

Abstract

Background: Radiation therapy (RT) has become a mainstay in the treatment of various malignancies. Unfortunately, a potential side effect of this modality is radiation-induced neuritis. The time-course is varied and the emergence of pain syndromes can be delayed by several years after the completion of treatment. Risk factors include the total radiation dose, fractionation schedule, and radiation field size. Spinal cord stimulation (SCS) may have an important role in attenuating the symptoms of radiation-induced neuritis. Objectives: We aim to characterize a case series of oncologic patients who underwent SCS to treat iatrogenic radiation neuritis of the lumbosacral nerve roots. Study Design: This is a retrospective review of 4 cases of patients who were eligible for either intrathecal drug delivery or SCS (magnetic resonance imaging [MRI] conditional devices for spine surveillance), of which each patient elected to have a SCS trial and possible permanent implantation. Setting: The data were collected at a major cancer center in the US. Methods: In this case series, we present 4 patients with radiation-induced neuropathy. For each patient, we describe the use of SCS, which uses electric impulse generation, in an effort to treat the patient’s symptoms. To assess for efficacy, we compare pre- and post-procedure numerical rating scale (NRS) pain scores and post-procedure pain medication requirements. Results: Each patient had marked improvement in their pain (> 50%) during the trial lead placement and proceeded to the permanent implant. In subsequent months and years, the patients decreased their opioid utilization and reported an improvement in their overall pain. Limitations: This case series is a small sample size of heterogeneous malignancies with radiation treatment to the spine. Conclusions: Radiation-induced neuritis remains a severe and limiting outcome that some patients must live with after RT. Survivors of malignancy have often found this pathology to severely impact their quality of life, and it is difficult to treat. We have described the utilization of spinal cord neuromodulation as an effective treatment modality in the spine tumor patient population. Further research is needed to maximize the benefit and ensure appropriate case selection in the future. Key words: Radiation neuritis, radiation neuropathy, oncologic lumbar radiculopathy, spinal cord stimulation, neuromodulation, dorsal column stimulation, spinal tumor pain, MRI conditional spinal cord stimulation