Objectives: Identifying ways in which acute manifestations of symptoms following chemotherapy and radiation therapy can be differentiated in the cancer population with a focus on a rare diagnosis of radiation-induced lumbosacral plexopathy in a medically complex cancer patient.
Design: A literature review was performed for a case report involving the rare occurrence of radiation-induced lumbar plexopathy in a medically complex cancer patient.
Results: Literature reveals the diagnosis of radiation-induced lumbar plexopathy is not common and for our patient, given such a low dose with an acute presentation, rare. Building a strong differential diagnosis can help with identification and management of patients to ensure the pathology is not missed.
Conclusions: When treating cancer patients, one must account for not only cancer pathology but also treatment dose, timing, and side effects in addition to new and pre-morbid conditions. This involves coordinating care among a variety of specialties to create an integrated healthcare team, with the ever-growing need for experts in the cancer rehabilitation field.
With improvements in identifying and diagnosing cancer earlier on as well as the development of better lifesaving interventions comes the increase in survivorship of cancer patients. Unfortunately, as a result of these extended prognoses comes the potential for complications following treatment. Some of these complications present as neuromuscular pathology that can be directly linked to cancer drugs and radiation therapy. These range from neuropathies to plexopathies, radiculopathies, and more and are seen in longterm cancer survivors with presentations that can be masked by other medical problems. The difficulty lies in assessing and developing a strong differential to address patient concerns when a symptom arises that falls within this realm. In many cases, there is delay in establishing the correct diagnosis, which can postpone appropriate treatment. Often this delay is a result of poor communication, poor history taking, and a lack of early cancer rehabilitation expertise. This study seeks to combat the delay in diagnosis, address the barriers of multi-specialty treatment teams, and encourage early consultation of cancer rehabilitation experts to reduce morbidity and improve functionality. In order to identify ways in which acute manifestations of symptoms following chemotherapy and radiation therapy can be differentiated in the cancer population, a literature review was performed following the evaluation of a cancer rehabilitation case report. The case involves the rare occurrence of radiation-induced lumbar plexopathy in a medically complex cancer patient.
An 80-year-old female with a past medical history of stage IIIB cervical carcinoma status post volume directed curative low-dose radiation therapy with radio-sensitizing cisplatin and sarcoidosis presented on February 2019 in the cancer rehabilitation clinic with 6 months of worsening right greater than left lower extremity numbness, tingling, and weakness. The symptoms had begun one month after completing chemoradiation therapy. There was no associated back pain and the patient denied bowel and bladder dysfunction. Prior to her presentation, the working diagnosis was a chemotherapy-induced peripheral neuropathy. The patient’s cancer treatment took place from April of 2018 to June of 2018 and follow up imaging showed interval complete metabolic response to therapy with marked interval anatomic and metabolic improvement with no new evidence of distant metastatic disease. At the time of presentation in February of 2019, she was transferring at a wheelchair level. Electrodiagnostic studies of the lower extremities were consistent with bilateral multilevel lumbosacral radiculopathy at the L3, L4, and L5 levels as well as sensory and motor polyneuropathy. The latter findings were consistent with chemotherapy induced polyneuropathy as cisplatin is known to affect the dorsal root ganglion. However the patient continued to have worsening sensory deficits and weakness in the distribution of the above radicular findings that did not match with the diagnosis of chemotherapy induced neuropathy.
A lumbar spine magnetic resonance imaging study was obtained and demonstrated mild to moderate lumbar spondylotic changes. A magnetic resonance imaging study of the lumbosacral plexus showed asymmetric signal and enhancement of the right lumbosacral plexus along with segmental abnormalities of bilateral sciatic nerves. Confounding the patient's presentation was her past medical history of sarcoidosis, which is also known to cause peripheral neuropathy. However, this patient’s symptoms did not correlate with sarcoidosis related peripheral neuropathy, which is a diffuse painful small-fiber neuropathy often mistaken for fibromyalgia. This patient instead was found on exam to have altered sensation to light touch along the bilateral dorsal (including the first dorsal webspace) and plantar aspects of the feet in addition to right more than left anterolateral pretibial areas as well as persistent weakness in the right more than the left lower extremity.
After discussion among physiatry, neuroradiology, and radiation oncology, she was diagnosed with radiation-induced plexopathy, which explains her progressive weakness, numbness, and tingling. This is a rare diagnosis given the low dose of radiation to the region and the acute onset of the symptoms. Her treatment included 45 Gy total for the first phase in 25 fractions followed by an additional boost to the parametria followed by brachytherapy with Syed implants and 70 Gy external beam radiation therapy. The diagnosis is unusual in that it is not typical given the distribution or acute progression of the patient’s symptoms. In addition, there was no electrodiagnostic evidence of myokymia, a common finding associated with such pathology.
For management, the patient was prescribed physical therapy to address range of motion, strengthening, and gait training with assistive devices. This case represents the importance of establishing coordinated care with an interdisciplinary healthcare team for the cancer population. With improvements in oncology treatment and survivorship, the long-term sequelae of cancer and its treatment have become more prevalent. It is essential to obtain a timely and thorough medical history.
Delay in medical care for the described patient led to an initial missed diagnosis for over six months. Inter-departmental discussion with expert cancer rehabilitation oversight facilitated the identification of this condition. The diagnosis for this case is a rarity given the low dose of radiation received and the timeline between therapy and symptom presentation. Radiation-induced lumbosacral plexopathy is only seen in 1.3% to 6.67% of patients. These patients are usually diagnosed following higher doses of radiation therapy and present years later. The condition itself is often due to microvascular injury and fibrosis and known to be commonly irreversible. Communication is necessary to diagnose and treat presenting complaints of cancer patients in order to differentiate between pre-morbid etiology, new medical conditions, complications related to cancer therapy and cancer pathology.
When treating individuals in the cancer population, one must account for not only cancer pathology but also what medication the patient received, when the patient received it, what the dose of the treatment was, the timing of the patient’s symptom onset, and the side effects associated with the therapy in addition to new and pre-morbid medical conditions. This type of assessment involves coordinating care among a variety of specialties in order to create an integrated healthcare team that can communicate and collaborate to provide the highest quality care for the patient. Most importantly, this case demonstrates the ever-growing need for experts in the cancer rehabilitation field.