Surgical resection of symptomatic, benign intradural extramedullary (IDEM) spine tumors provides rapid, significant, and durable improvements in patient-reported outcomes (PROs), according to our study published recently in Neurosurgery. (1)
Historically, these tumors have been managed with open surgical resection. While PRO data have been sparse, there are increasing reports of radiosurgical management of these lesions without robust quality-of-life data.
Our prospective, single-center, observational cohort study of 57 patients is the largest analysis of prospectively collected PROs for patients undergoing surgery for symptomatic, benign IDEM spine tumors to date. (1)
We found that surgical resection resulted in statistically significant improvements in all composite scores for pain-severity, pain-interference, and overall pain experience (p < 0.0001), as well as all composite scores for core symptom severity, spine tumor, and disease interference (p<0.01). Specifically, surgical intervention resulted in improved or stable rates of 82 percent for pain severity, 87 percent for activities of daily life, and 87 percent for core symptom severity. These improvements were noted at all follow-up time points over an average follow-up period of 15 months. (1)
Our findings demonstrate the value of using cancer-validated PRO tools to assess symptom control after surgical resection of spine tumors quantitatively. Our study establishes a framework for future studies comparing open and radiosurgical interventions for these tumors.
At Memorial Sloan Kettering Cancer Center (MSK), our dedicated spine tumor surgeons provide world-class care for more than 1,500 patients annually including those with benign spine tumors, malignant lesions, and degenerative spinal conditions that result from cancer or its treatment. Our goal is the same for each patient — to optimize their outcome while maintaining or improving their quality of life.
Surgical Approaches for Intradural Medullary Spine Tumors
As the name indicates, IDEM spine tumors are located inside the dura and outside the actual spinal cord. IDEM tumors include meningiomas, schwannomas, neurofibromas, and filum terminale ependymomas. They are usually benign. However, patients with these tumors experience significant pain and neurological symptoms due to progressive spinal cord compression.
Studies have demonstrated that gross total resection of benign, noninfiltrative tumors using microsurgical techniques is safe, efficacious, and results in a low risk of recurrence. (2), (3), (4), (5) However, some groups have investigated the role of stereotactic radiosurgery as a way of managing benign, intradural lesions with minimal toxicity, (6), (7), (8), (9) and many studies have demonstrated good local control with stereotactic radiosurgery in treating spinal metastatic disease. (10), (11), (12), (13)
While both the open surgical and radiosurgical literature discuss the importance of symptomatic relief in patients’ outcomes when treating IDEM tumors, none have prospectively assessed PROs with cancer-validated tools. (2), (4), (5), (14), (15)
We prospectively collected PROs in consecutive patients undergoing open surgical resection of IDEM lesions at MSK from April 2015 to December 2018. A total of 70 patients met the inclusion criteria, which were imaging confirming an IDEM tumor, undergoing surgical treatment, a diagnosis of benign disease on pathology, and the ability to use reporting tools. Thirteen patients were excluded for not having sufficient preoperative or postoperative PROs, leaving 57 patients for our final analysis. No patients had received prior treatment for IDEM lesions. (1)
Using two validated PRO measures, the Brief Pain Index (BPI) and MD Anderson Symptom Inventory (MDASI), (16), (17), (18), (19), (20) we collected data three-weeks preoperatively, followed by three- to six-month intervals for a year postoperatively, and then yearly until follow-up concluded. BPI questionnaires included four items related to pain, seven to disease interference, and one to relief. The disease interference items generated a BPI interference score, and the pain items generated a pain score. Combining these two scores generated an overall BPI patient pain experience score. (21) The MDASI questionnaire evaluated 13 core symptoms that we combined into a core symptom score. It also included six disease interference items we combined to generate a disease interference score. Similarly, we generated an MDASI spine-tumor-specific score from five spine-specific items in the questionnaire. (1)
Among the 57 patients in our study, 39 were female (68 percent), with a mean age of 57. The pathologies treated included 35 schwannomas (61 percent), 18 meningiomas (32 percent), two neurofibromas (4 percent), one paraganglioma (2 percent), and one mixed schwannoma/neurofibroma (2 percent). (1)
Most surgeries (84 percent) were two- or three-level laminectomies, with most involving the thoracic spine (58 percent) or the lumbar spine (30 percent), with the latter inclusive of the cauda equina and conus medullaris. (1)
Ninety-nine percent of patients had lesions causing high-grade spinal cord compression analogous to grades 2 or 3 epidural spinal cord compression. Most patients were evaluated as “E” on the American Spinal Association Impairment Scale and had a median Medical Research Council Muscle Scale grade of 5, indicating full strength in all muscle groups (53 patients, 93 percent), and had an Eastern Cooperative Oncology Group Performance Status score of 1 (46 patients, 81 percent). (1)
The three composite BPI scores on pain severity, pain interference with daily life, and overall pain experience were significantly improved for all patients at all time points. (p < 0.0001). At each postoperative timepoint, significant improvements in all BPI scores remained durable.
The only individual BPI item that did not show improvement after surgery was the “relief category” (p = 0.80). This discontinuity may have resulted since the BPI tool asks patients to report how much relief medications have provided in the past 24 hours. If they experienced substantial pain before surgery, their responses might reflect that surgery led to pain relief, not medications. (1)
The MDASI questionnaire results at the last follow-up revealed significant improvements in pain, fatigue, sleep, distress, appetite, drowsiness, sadness, numbness, spine pain, and limb weakness (p < 0.05). General activity level, mood, work, relations, walking, and overall enjoyment of life were also significantly improved (p < 0.0001). All MDASI composite scores for core symptom severity, spine tumor, and interference were significantly improved compared to preoperative assessments (p < 0.01). Individual items that did not significantly improve included nausea, shortness of breath, memory, dry mouth, vomiting, bowel/bladder control, bowel patterns, and sexual function (p > 0.05 for all). All composite scores demonstrated significant improvements at each of the postoperative follow-up time points. (1)
The only significant preoperative predictor of improvement in BPI and MDASI PRO composite scores was tumor location, with a cervical site showing more improved scores. However, this finding must be interpreted with caution as only seven patients had tumors in this area. No other factors, including the extent of resection, were significant predictors of postoperative PROs at the latest time point. (1)
Among 57 patients in our study, seven (12 percent) experienced postoperative complications that required surgical interventions. Three patients were treated with wound oversewing or lumbar drainage to manage cerebrospinal fluid leaks. Two patients received revision operations to address wound breakdown. One patient developed a lumbar pseudomeningocele and hydrocephalus and required a ventriculoperitoneal shunt, and one patient received medical management for urinary retention. (1)
Overall, our study provides useful insights for counseling patients with symptomatic, benign IDEM tumors and establishes a framework for comparing outcomes for patients receiving open versus stereotactic radiosurgery approaches in future research. While several groups have focused on stereotactic radiosurgery for treating these lesions in patients deemed poor candidates for open procedures due to comorbidities, tumor location, or recurrence after open resection, (14), (15)an understanding of the patient experience is critical for determining whether a less invasive procedure is inferior, equivalent, or superior to an open surgical approach.
The study was supported in part by the National Institutes of Health/National Cancer Institute MSK Support Grant P30 CA008748. All study authors declared no personal, financial, or institutional interest in any drugs, materials, or devices described in the paper.