Case Diagnosis: Post-irradiation Sarcoma Case Description: A 58-year-old woman with a history of stage IIIB squamous cell carcinoma of the cervix who was treated with chemoradiation, considered in remission 5 years prior on PET CT, and was under every 6-months surveillance for recurrence by gynecology. She presented to the Emergency Department for severe back pain, left sided sciatica, and paresthesias. In the absence of fracture or cord compression, she was discharged with recommendations for primary care follow-up. This took place over the telephone with referral to the spine center. One week later, her pain progressed to 10+/10 with dense left leg numbness, and multiple falls. Physiatry ordered a lumbar MRI for focal neurologic findings on exam, which revealed a large destructive lesion of the left ilium and left hemisacrum with soft tissue extension. This was later determined to be undifferentiated sarcoma, likely due to prior radiation. She is currently undergoing palliative chemotherapy. Discussions: Post-irradiation sarcomas (PIS) are a relatively rare event and exhibit dose dependency. Sarcomas can present with bone pain that can be worse at night and signs and symptoms of compression of surrounding structures. The pelvis is a common site for sarcoma development. Cases of PIS have presented in even just a few months post radiation therapy. The prognosis of patients with PIS is poorer than those with primary sarcomas. This patient would require hemipelvectomy to attempt curative treatment. Conclusions: PIS are typically aggressive, have poor prognosis, and can develop within months of high doses of radiation therapies; clinicians index of suspicion for sarcomas in patients with a history of radiation must be high. Evaluation for progressive pain, weakness, and numbness may not be amenable to telemedicine until technology improves. Patients that present with signs and symptoms of progressive nerve compression and bone pain should be re-examined early on.

Radiofrequency (RF) neurotomy is an interventional procedure used to alleviate certain types of low back pain. RF energy is used to thermally coagulate the specific nerves that transmit pain signals. Recent evidence has shown that this procedure demonstrates significant efficacy in relieving low back pain in lumbar zygapophysial joints, and research is ongoing to determine if pain relief for the sacroiliac joint is also possible. This article provides an evidence-based background for performing RF neurotomy, discusses the relevant anatomy, and highlights the indications and technique for lumbar and sacral RF neurotomy.