Faculty Bibliography

BACKGROUND:Conventional external beam radiation and stereotactic radiosurgery are common radiation techniques used to treat spinal tumors. Intraoperative brachytherapy (BT) may serve as an alternative when other options have been exhausted or as an adjunct in combination with other therapies. The objective of this study was to systematically review the literature on BT use in spinal tumor surgery. METHODS:PubMed and Embase databases were systematically queried for literature reporting the use of BT in the surgical treatment of spinal tumors. PRISMA guidelines were followed. A meta-analysis was performed. RESULTS:Of the 203 initial articles queried, 15 studies were included. Of the 370 total patients described, 78% were treated for spine metastases. Indications for BT included tumors refractory to previous treatments and inability to tolerate chemotherapy, radiation, and/or open surgery. Seed placement was the most common method of delivery (58%) compared with plaques (42%). BT was placed during an open procedure in 52%, and of the remaining percutaneous procedures, 47% were combined with cement augmentation. Tumor recurrence rates varied from 13% to 49%. Seven studies reporting visual analog scale scores reported significant improvement in pain control. CONCLUSIONS:BT was used to treat metastatic disease in patients who failed previous therapies and could not tolerate open surgery or further therapy. This review summarizes the major findings in the available literature pertaining to patient background, indications, and outcomes. Spinal BT seems to be a viable option for spine tumor treatment and should be made available at treating centers.

BACKGROUND:Minimal access surgery (MAS) allows for an early return to systemic and radiation therapy in patients with cancer, leading to its increasing usage in the treatment of spinal metastases. Systematic examination of surgical indications resulted in the development of an algorithm for implementation of MAS in the treatment of spinal metastases. The objective of the present study was to evaluate a spine tumor MAS treatment algorithm using patient-reported outcomes for patients with cancer undergoing treatment of spinal metastases. METHODS:We performed a prospective cohort study of patients who had undergone spinal percutaneous instrumented stabilization with the addition of MAS spinal cord or nerve root decompression and/or kyphoplasty when indicated at a tertiary cancer center from December 2013 to August 2016. Validated patient-reported outcome measures, including the Brief Pain Inventory and the MD Anderson Symptom Inventory-spine module, were used. The patient-reported outcome measures were collected and compared at baseline, 3 months, and long-term follow-up (range, 4.5-12 months). RESULTS:A total of 51 patients were included. MAS resulted in a statistically significant decrease in the severity of pain and improved activity, ability to work, and enjoyment of life (P < 0.001). The improvement was reported at the short- and long-term follow-up points. CONCLUSIONS:We present our treatment algorithm for MAS implementation in the treatment of thoracolumbar spinal metastases. Prospectively collected data have demonstrated that using this algorithm, MAS surgery for the treatment of spinal metastases results in significant decreases in pain severity and symptom interference with daily activities.

BACKGROUND:Spine and nonspine skeletal metastases occur in more than 80% of patients with prostate cancer. OBJECTIVE:To examine the characteristics of the patient population undergoing surgery for the treatment of prostate cancer metastatic to the spine. METHODS:A retrospective chart review was performed on all patients treated at our institution from June 1993 to August 2014 for surgical management of metastatic spine disease from prostate cancer. RESULTS:During the study period, 139 patients with 157 surgical lesions underwent surgery for metastatic spine disease. Decompression for high-grade epidural spinal cord compression was required for 126 patients with 143 lesions. Preoperatively, 69% had a motor deficit and 21% were nonambulatory, with 32% due to motor weakness. At surgery, 87% of patients had hormone-refractory prostate cancer (HRPC) and 61% failed prior radiation. Median overall survival for HRPC patients was 6.6 mo (95% confidence interval [CI]: 5.6-8.6) while the median overall survival for hormone-sensitive patients was 16.3 mo (95% CI: 4.0-26.6). CONCLUSION:The majority of patients undergoing surgery for prostate cancer metastases to the spine were refractory to hormone therapy, indicating that patients with hormone-sensitive prostate cancer are unlikely to develop symptomatic spinal cord compression or spinal instability. A significant number of HRPC patients presented with neurological deficits attributable to spinal cord compression. Vigilant monitoring for the development of signs and symptoms of epidural spinal cord compression and spinal instability in hormone-refractory patients is recommended. Surgical decision making may be affected by the much shorter postoperative survival for HRPC patients as compared to patients with hormone-sensitive cancer.

OBJECTIVEThe purpose of this study was to investigate the spectrum of current treatment protocols for managing newly diagnosed chordoma of the mobile spine and sacrum.METHODSA survey on the treatment of spinal chordoma was distributed electronically to members of the AOSpine Knowledge Forum Tumor, including neurosurgeons, orthopedic surgeons, and radiation oncologists from North America, South America, Europe, Asia, and Australia. Survey participants were pre-identified clinicians from centers with expertise in the treatment of spinal tumors. The suvey responses were analyzed using descriptive statistics.RESULTSThirty-nine of 43 (91%) participants completed the survey. Most (80%) indicated that they favor en bloc resection without preoperative neoadjuvant radiation therapy (RT) when en bloc resection is feasible with acceptable morbidity. The main area of disagreement was with the role of postoperative RT, where 41% preferred giving RT only if positive margins were achieved and 38% preferred giving RT irrespective of margin status. When en bloc resection would result in significant morbidity, 33% preferred planned intralesional resection followed by RT, and 33% preferred giving neoadjuvant RT prior to surgery. In total, 8 treatment protocols were identified: 3 in which en bloc resection is feasible with acceptable morbidity and 5 in which en bloc resection would result in significant morbidity.CONCLUSIONSThe results confirm that there is treatment variability across centers worldwide for managing newly diagnosed chordoma of the mobile spine and sacrum. This information will be used to design an international prospective cohort study to determine the most appropriate treatment strategy for patients with spinal chordoma.

OBJECTIVEPercutaneous vertebral augmentation procedures such as vertebroplasty and kyphoplasty are often performed in cancer patients to relieve mechanical axial-load pain due to pathological collapse deformities. The collapsed vertebrae in these patients can be associated with varying degrees of spinal canal compromise that can be worsened by kyphoplasty. In this study the authors evaluated changes to the spinal canal, in particular the cross-sectional area of the thecal sac, following balloon kyphoplasty (BKP) prior to stereotactic radiosurgery (SRS).METHODSThe authors retrospectively reviewed the records of all patients with symptomatic vertebral compression fractures caused by metastatic disease who underwent kyphoplasty prior to single-fraction SRS. The pre-BKP cross-sectional image, usually MRI, was compared to the post-BKP CT myelogram required for radiation treatment planning. The cross-sectional area of the thecal sac was calculated pre- and postkyphoplasty, and intraprocedural CT imaging was reviewed for epidural displacement of bone fragments, tumor, or polymethylmethacrylate (PMMA) extravasation. The postkyphoplasty imaging was also evaluated for evidence of fracture progression or fracture reduction.RESULTSAmong 30 consecutive patients, 41 vertebral levels were treated with kyphoplasty, and 24% (10/41) of the augmented levels showed a decreased cross-sectional area of the thecal sac. All 10 of these vertebral levels had preexisting epidural disease and destruction of the posterior vertebral body cortex. No bone fragments were displaced posteriorly. Minor epidural PMMA extravasation occurred in 20% (8/41) of the augmented levels but was present in only 1 of the 10 vertebral segments that showed a decreased cross-sectional area of the thecal sac postkyphoplasty.CONCLUSIONSIn patients with preexisting epidural disease and destruction of the posterior vertebral body cortex who are undergoing BKP for pathological fractures, there is an increased risk of further mass effect upon the thecal sac and the potential to alter the SRS treatment planning.

[This corrects the article DOI: 10.1093/nop/npx017.][This corrects the article DOI: 10.1093/nop/npx017.].

AIM/OBJECTIVE:to identify preoperative factors associated with morbidity/mortality, hospital length of stay (LOS), 30-day readmission and operation rates following spinal stereotactic radiosurgery (SRS) for spinal tumors. METHODS:The American College of Surgeons National Quality Improvement Program was queried from 2012 to 2014 to identify patients undergoing SRS for spinal tumors. Logistic regression was performed to identify predictors. RESULTS:2714 patients were identified; 6.8% had major morbidity or mortality, 6.9% were readmitted within 30 days and 4.3% had a subsequent operation within 30 days. Age, BMI and American Society of Anesthesiologist (ASA) class were predictive of LOS. Major morbidity was predicted by age >80, BMI >35, high ASA, pretreatment functional dependence and baseline comorbidities. Predictors of operation within 30 days included preoperative steroid use, renal failure, BMI >35 and if the treatment was nonelective. DISCUSSION/CONCLUSIONS:4-7% of patients undergoing SRS for spinal tumors have morbidity following the procedure. Factors predictive of morbidity, LOS, and subsequent operation included age, BMI, baseline comorbidities and functional status. CONCLUSION/CONCLUSIONS:Identification of preoperative patient-specific factors that are predictive of post-treatment outcome will aid in patient selection and patient counseling leading to greater patient satisfaction and hospital efficiency.

Patients with cancer are frequently affected by spinal metastases. Treatment is palliative, with the principle goals of pain relief, preservation of neurologic function, and improvement in quality of life. In the past decade, we have witnessed a dramatic change in the treatment paradigms due to the development of improved surgical strategies and systemic and radiation therapy. The most important change to these paradigms has been the integration of spinal stereotactic radiosurgery (SSRS), allowing delivery of tumoricidal radiation doses with sparing of nearby organs at risk. High-dose SSRS provides durable tumor control when used either as definitive therapy or as a postoperative adjuvant therapy. Integration of SSRS has fundamentally changed the indications for and type of surgery performed for metastatic spine tumors. Although the role for surgical intervention is well established, a clear trend toward less-aggressive, often minimally invasive techniques has been observed. Targeted therapies are also rapidly changing the way cancer is being treated and have demonstrated improved survival for a number of malignancies. As these treatment decisions become more complex, a multidisciplinary approach including medical oncologists, radiation oncologists, surgeons, interventionalists, and pain specialists is required. In this article, the current evidence affecting the treatment of spinal metastases is integrated into a decision framework that considers four principal assessments of a patient's spine disease: NOMS (neurologic, oncologic, mechanical instability, and systemic disease).