Use of "MAPs" for determining the optimal surgical approach to metastatic disease of the thoracolumbar spine: anterior, posterior, or combined. Invited submission from the Joint Section Meeting on Disorders of the Spine and Peripheral Nerves, March 2004

Stereotactic Body Radiation Therapy With Simultaneous Integrated Boost in Patients With Spinal Metastases

Stereotactic body radiation therapy in patients with spine metastases maximizes local tumor control and preserves neurologic function. A novel approach could be the use of stereotactic body radiation therapy with simultaneous integrated boost delivering modality. The aim of the present study is to report our experience in the treatment of spine metastases using a frameless radiosurgery system delivering stereotactic body radiation therapy–simultaneous integrated boost technique. The primary endpoints were the pain control and the time to local progression; the secondary ones were the overall survival and toxicity. A total of 20 patients with spine metastases and 22 metastatic sites were treated in our center with stereotactic body radiation therapy–simultaneous integrated boost between December 2007 and July 2018. Stereotactic body radiation therapy–simultaneous integrated boost treatments were delivered doses of 8 to 10 Gy in 1 fraction to isodose line of 50%. The median follow-up was 35 months (range: 12-110). The median time to local progression for all patients was not reached and the actuarial 1-, 2-, and 3-years local free progression rate was 86.36%. In 17 of 20 patients, a complete pain remission was observed and 3 of 20 patients had a partial pain remission (complete pain remission + partial pain remission: 100%). The median overall survival was 38 months (range 12-83). None of the patients experienced neither radiation adverse events (grade 1-4) nor reported pain flair reaction. None of the patients included in our series experienced vertebral compression fracture. Spine radiosurgery with stereotactic body radiation therapy–simultaneous integrated boost is safe. The use of this modality in spine metastases patients provides an excellent local control.

Factors affecting survival in 43 consecutive patients after surgery for spinal metastases from thyroid carcinoma

OBJECT

Spinal metastases account for the majority of bone metastases from thyroid cancer. The objective of the current study was to analyze a series of consecutive patients undergoing spinal surgery for thyroid cancer metastases in order to identify factors that influence overall survival.

METHODS

The authors retrospectively reviewed the records of all patients who underwent surgery for spinal metastases from thyroid cancer between 1993 and 2010 at the University of Texas MD Anderson Cancer Center.

RESULTS

Forty-three patients met the study criteria. Median overall survival was 15.4 months (95% CI 2.8-27.9 months) based on the Kaplan-Meier method. The median follow-up duration for the 4 patients who were alive at the end of the study was 39.4 months (range 1.7-62.6 months). On the multivariate Cox analysis, progressive systemic disease at spine surgery and postoperative complications were associated with worse overall survival (HR 8.98 [95% CI 3.46-23.30], p < 0.001; and HR 2.86 [95% CI 1.30-6.31], p = 0.009, respectively). Additionally, preoperative neurological deficit was significantly associated with worse overall survival on the multivariate analysis (HR 3.01 [95% CI 1.34-6.79], p = 0.008). Conversely, preoperative embolization was significantly associated with improved overall survival on the multivariate analysis (HR 0.43 [95% CI 0.20-0.94], p = 0.04). Preoperative embolization and longer posterior construct length were significantly associated with fewer and greater complications, respectively, on the univariate analysis (OR 0.24 [95% CI 0.06-0.93] p = 0.04; and OR 1.24 [95% CI 1.02-1.52], p = 0.03), but not the multivariate analysis.

CONCLUSIONS

Progressive systemic disease, postoperative complications, and preoperative neurological deficits were significantly associated with worse overall survival, while preoperative spinal embolization was associated with improved overall survival. These factors should be taken into consideration when considering such patients for surgery. Preoperative embolization and posterior construct length significantly influenced the incidence of postoperative complications only on the univariate analysis.

Contemporary Treatment Strategy for Spinal Metastasis: The “LMNOP” System

The choice of treatment for spinal metastasis is complex because (1) it depends on several inter-related clinical and radiologic factors, and (2) a wide range of management options has evolved in recent years. While radiation therapy and surgery remain the cornerstones of treatment, radiosurgery and percutaneous vertebral augmentation have also established a role. Classification systems have been developed to aid in the decision-making process, and each has different strengths and weaknesses. The comprehensive scoring systems developed to date provide an estimate of life expectancy, but do not provide much advice on the choice of treatment. We propose a new decision model that describes the key factors in formulating the management plan, while recognizing that the care of each patient remains highly individualized. The system also incorporates the latest changes in technology. The LMNOP system evaluates the number of spinal Levels involved and the Location of disease in the spine (L), Mechanical instability (M), Neurology (N), Oncology (O), Patient fitness, Prognosis and response to Prior therapy (P).

Prognostic parameters and spinal metastases: a research study

OBJECT

To identify pre-operative prognostic parameters for survival in patients with spinal epidural neoplastic metastasis when the primary tumour is unknown.

METHODS

This study was a retrospective chart review of patients who underwent surgery for spinal epidural neoplastic metastases between February 1997 and January 2011. The inclusion criteria were as follows: known post-operative survival period, a Karnofsky Performance Score equal to or greater than 30 points and a post-operative neoplastic metastasis histological type. The Kaplan-Meier method was used to estimate post-operative survival, and the Log-Rank test was used for statistical inference.

RESULTS

A total of 52 patients who underwent 52 surgical procedures were identified. The mean age at the time of spinal surgery was 53.92 years (std. deviation, 19.09). The median survival after surgery was 70 days (95% CI 49.97-90.02), and post-operative mortality occurred within 6 months in 38 (73.07%) patients. Lung cancer, prostate cancer, myeloma and lymphoma, the 4 most common primary tumour types, affected 32 (61.53%) patients. The three identified prognostic parameters were the following: pre-operative walking incapacity (American Spinal Injury Association, A and B), present in 86.53% of the patients (p-value = 0.107); special care dependency (Karnofsky Performance Score, 10-40 points), present in 90.38% of the patients (p-value = 0.322); and vertebral epidural neoplastic metastases that were in contact with the thecal sac (Weinstein-Boriani-Biagini, sector D), present in 94.23% of the patients (p-value = 0.643). When the three secondary prognostic parameters were combined, the mean post-operative survival was 45 days; when at least one was present, the survival was 82 days (p-value = 0.175).

CONCLUSIONS

Walking incapacity, special care dependency and contact between the neoplastic metastases and the thecal sac can help determine the ultimate survival of this patient population and, potentially, which patients would benefit from surgery versus palliation alone. A 2- to 3-month post-operative survival period justified surgical treatment.

Incorporating the Spine Instability Neoplastic Score into a Treatment Strategy for Spinal Metastasis: LMNOP

Study Design Review. Objective To describe a decision framework that incorporates key factors to be considered for optimal treatment of spinal metastasis and highlight how this system incorporates the Spinal Instability Neoplastic Score (SINS). Methods We describe how treatment options for spinal metastasis have broadened in recent years with advancements in stereotactic radiosurgery, vertebral augmentation, and other minimally invasive techniques. We discuss classification-based approaches to the treatment of spinal metastasis versus principles-based approaches and argue that the latter may be more appropriate for optimal patient informed consent. Case examples are provided. Results Scoring systems at best produce an estimate of life expectancy but fall short in incorporating all of the relevant factors that determine which treatment(s) may be indicated. We advocate a principle-based decision framework called LMNOP that considers: (L) location of disease with respect to the anterior and/or posterior columns of the spine and number of spinal levels involved (contiguous or non-contiguous); (M) mechanical instability as graded by SINS; (N) neurology (symptomatic epidural spinal cord compression); (O) oncology (histopathologic diagnosis), particularly with respect to radiosensitivity; and (P) patient fitness, patient wishes, prognosis (which is mostly dependent on tumor type), and response to prior therapy. Conclusions LMNOP is the first systematic approach to spinal metastasis that incorporates SINS. It is easy to remember, it addresses clinical factors not directly addressed by other systems, and it is adaptable to changes in technology.

Optimal approach to circumferential decompression and reconstruction for thoracic spine metastatic disease

BACKGROUND

Circumferential decompression has been demonstrated to be the first-line therapy for patients with metastatic tumors in the thoracic spine requiring surgical intervention. However, there is significant debate regarding whether these tumors are best accessed anteriorly utilizing a thoracotomy or posteriorly. We used decision analysis to determine which approach yields greater health-related quality of life (QOL).

METHODS

We searched Medline, Embase, and the Cochrane Library for relevant articles published between 1990 and 2011 on anterior and posterior approaches to metastatic disease in the thoracic spine. QOL values for major treatment outcomes were determined using the existing literature. Separate models were created for ambulatory and nonambulatory patients. A Monte Carlo simulation and sensitivity analyses were used to determine which treatment strategy resulted in the highest QOL.

RESULTS

For ambulatory patients, an anterior approach resulted in a slightly higher QOL, and for nonambulatory patients, a posterior approach was favored, but these differences were not statistically significant.

CONCLUSIONS

Using a decision-analytic model, we found no significant difference in QOL resulting from anterior versus posterior approaches to metastatic lesions in the thoracic spine. Decisions should instead be based on surgeon comfort, tumor characteristics, anatomy of the lesion, patient-related factors, and goals of the operation.

Refinements to the simultaneous anterior-posterior approach to the thoracolumbar spine

The treatment of complex thoracolumbar disorders occasionally requires combined anterior and posterior approaches. Traditionally, these are either sequentially staged to occur during the same anesthesia procedure or alternatively performed on separate days. A less common option is the simultaneous anterior-posterior approach. The authors discuss the rationale for this approach in selected cases and illustrate a number of modifications to previous descriptions of the procedure. By slightly altering the incision, the risk of wound breakdown and infection has been reduced. The use of newly available positioning devices has allowed easy incorporation of fluoroscopy to guide the placement of spinal instrumentation. The authors have also expanded the use of the approach beyond the original oncological indications to include trauma and infection.

Thoracic vertebrectomy and spinal reconstruction via anterior, posterior, or combined approaches: clinical outcomes in 91 consecutive patients with metastatic spinal tumors

OBJECT

Adequate decompression of the thoracic spinal cord often requires a complete vertebrectomy. Such procedures can be performed from an anterior/transthoracic, posterior, or combined approach. In this study, the authors sought to compare the clinical outcomes of patients with spinal metastatic tumors undergoing anterior, posterior, and combined thoracic vertebrectomies to determine the efficacy and operative morbidity of such approaches.

METHODS

A retrospective review was conducted of all patients undergoing thoracic vertebrectomies at a single institution over the past 7 years. Characteristics of patients and operative procedures were documented. Neurological status, perioperative variables, and complications were assessed and associations with each approach were analyzed.

RESULTS

Ninety-one patients (mean age 55.5 +/- 13.7 years) underwent vertebrectomies via an anterior (22 patients, 24.2%), posterior (45 patients, 49.4%), or combined anterior-posterior approach (24 patients, 26.4%) for metastatic spinal tumors. The patients did not differ significantly preoperatively in terms of neurological assessments on the Nurick and American Spinal Injury Association Impairment scales, ambulatory ability, or other comorbidities. Anterior approaches were associated with less blood loss than posterior approaches (1172 +/- 1984 vs 2486 +/- 1645 ml, respectively; p = 0.03) or combined approaches (1172 +/- 1984 vs 2826 +/- 2703 ml, respectively; p = 0.05) but were associated with a similar length of stay compared with the other treatment cohorts (11.5 +/- 9.3 [anterior] vs 11.3 +/- 8.6 [posterior] vs 14.3 +/- 6.7 [combined] days; p = 0.35). The posterior approach was associated with a higher incidence of wound infection compared with the anterior approach cohort (26.7 vs 4.5%, respectively; p = 0.03), and patients in the posterior approach group experienced the highest rates of deep vein thrombosis (15.6% [posterior] vs 0% [other 2 groups]; p = 0.02). However, the posterior approach demonstrated the lowest incidence of pneumothorax (4.4%; p < 0.0001) compared with the other 2 cohorts. Duration of chest tube use was greater in the combined patient group compared with the anterior approach cohort (8.8 +/- 6.2 vs 4.7 +/- 2.3 days, respectively; p = 0.01), and the combined group also experienced the highest rates of radiographic pleural effusion (83.3%; p = 0.01). Postoperatively, all groups improved neurologically, although functional outcome in patients undergoing the combined approach improved the most compared with the other 2 groups on both the Nurick (p = 0.04) and American Spinal Injury Association Impairment scales (p = 0.03).

CONCLUSIONS

Decisions regarding the approach to thoracic vertebrectomy may be complex. This study found that although anterior approaches to the thoracic vertebrae have been historically associated with significant pulmonary complications, in our experience these rates are nevertheless quite comparable to that encountered via a posterior or combined approach. In fact, the posterior approach was found to be associated with a higher risk for some perioperative complications such as wound infection and deep vein thromboses. Finally, the combined anteriorposterior approach may provide greater ambulatory and neurological improvements in properly selected patients.

Spine surgery training and competence of European neurosurgical trainees

BACKGROUND

Little is known about the nature of spine surgery training received by European neurosurgical trainees during their residency and the level of competence they acquire in dealing with spinal disorders.

METHODS

A three-part questionnaire entailing 32 questions was devised and distributed to the neurosurgical trainees attending the EANS (European Association of Neurosurgical Societies) training courses of 2004.

RESULTS

Of 126 questionnaires, 32% were returned. The majority of trainees responding to the questionnaire were in their final (6(th)) year of training or had completed their training (60.3% of total). Spinal surgery training in European residency programs has clear strengths in the traditional areas of microsurgical decompression for spinal stenosis and disc herniation (77-90% competence in senior trainees). Deficits are revealed in the management of spinal trauma (34-48% competence in senior trainees) and spinal conditions requiring the use of implants and anterior approaches, with the exception of anterior cervical stabilisation.

CONCLUSIONS

European neurosurgical trainees possess incomplete competence in dealing with spinal disorders. EANS trainees advocate the development of a postresidency spine subspecialty training program.

Surgical management of prostate cancer metastatic to the spine

Object

Significant improvements in neurological function and pain relief are the benefits of aggressive surgical management of spinal metastatic disease. However, there is limited literature regarding the management of tumors with specific histological features. In this study, a series of patients undergoing spinal surgery for metastatic prostate cancer were reviewed to identify predictors of survival and functional outcome.

Methods

The authors retrospectively reviewed the records of all patients who were treated with surgery for prostate cancer metastases to the spine between 1993 and 2005 at a single institution. Particular attention was given to initial presentation, operative management, clinical and neurological outcomes, and factors associated with complications and overall survival.

Results

Forty-four patients underwent a total of 47 procedures. The median age at spinal metastasis was 66 years (range 50–84 years). Twenty-four patients had received previous external-beam radiation to the site of spinal involvement, with a median dose of 70 Gy (range 30–74 Gy). Frankel scores on discharge were significantly improved when compared with preoperative scores (p = 0.001). Preoperatively, 32 patients (73%) were walking and 33 (75%) were continent. On discharge, 36 (86%) of 42 patients were walking, and 37 (88%) of 42 were continent. Preoperatively, 40 patients (91%) were taking narcotics, with a median morphine equivalent dose of 21.5 mg/day, and 28 patients (64%) were taking steroids, with a median dose of 16 mg/day. At discharge, the median postoperative morphine equivalent dose was 12 mg/day, and the median steroid dose was 0 mg/day (p < 0.001). Complications occurred in 15 (32%) of 47 procedures, with 9 (19%) considered major, and there were 4 deaths within 30 days of surgery. The median overall survival was 5.4 months. Gleason score (p = 0.002), total number of metastases (p = 0.001), and the degree of spinal canal compression (p = 0.001) were independent predictors of survival. Age ≥ 65 years at the time of surgery was an independent predictor of a postoperative complication (p = 0.005).

Conclusions

In selected patients with prostate cancer metastases to the spine, aggressive surgical decompression and spinal reconstruction is a useful treatment option. The results show that on average, neurological outcome is improved and use of analgesics is reduced. Gleason score, metastatic burden, and degree of spinal canal compression may be associated with survival following surgery, and thus should be considered carefully prior to opting for surgical management.

Surgical treatment strategies and outcome in patients with breast cancer metastatic to the spine: a review of 87 patients

Aggressive surgical management of spinal metastatic disease can provide improvement of neurological function and significant pain relief. However, there is limited literature analyzing such management as is pertains to individual histopathology of the primary tumor, which may be linked to overall prognosis for the patient. In this study, clinical outcomes were reviewed for patients undergoing spinal surgery for metastatic breast cancer. Respective review was done to identify all patients with breast cancer over an eight-year period at a major cancer center and then to select those with symptomatic spinal metastatic disease who underwent spinal surgery. Pre- and postoperative pain levels (visual analog scale [VAS]), analgesic medication usage, and modified Frankel grade scores were compared on all patients who underwent surgery. Univariate and multivariate analyses were used to assess risks for complications. A total of 16,977 patients were diagnosed with breast cancer, and 479 patients (2.8%) were diagnosed with spinal metastases from breast cancer. Of these patients, 87 patients (18%) underwent 125 spinal surgeries. Of the 76 patients (87%) who were ambulatory preoperatively, the majority (98%) were still ambulatory. Of the 11 patients (13%) who were nonambulatory preoperatively, four patients were alive at 3 months postoperatively, three of which (75%) regained ambulation. The preoperative median VAS of six was significantly reduced to a median score of two at the time of discharge and at 3, 6, and 12 months postoperatively (P < 0.001 for all time points). A total of 39% of patients experienced complications; 87% were early (within 30 days of surgery), and 13% were late. Early major surgical complications were significantly greater when five or more levels were instrumented. In patients with spinal metastases specifically from breast cancer, aggressive surgical management provides significant pain relief and preservation or improvement of neurological function with an acceptably low rate of complications.

Surgical strategy for spinal metastases

STUDY DESIGN

A new surgical strategy for treatment of patients with spinal metastases was designed, and 61 patients were treated based on this strategy.

OBJECTIVES

To propose a new surgical strategy for the treatment of patients with spinal metastases.

SUMMARY OF BACKGROUND DATA

A preoperative score composed of six parameters has been proposed by Tokuhashi et al for the prognostic assessment of patients with metastases to the spine. Their scoring system was designed for deciding between excisional or palliative procedures. Recently, aggressive surgery, such as total en bloc spondylectomy for spinal metastases, has been advocated for selected patients. Surgical strategies should include various treatments ranging from wide or marginal excision to palliative treatment with hospice care.

METHODS

Sixty-seven patients with spinal metastases who had been treated from 1987-1991 were reviewed, and prognostic factors were evaluated retrospectively (phase 1). A new scoring system for spinal metastases that was designed based on these data consists of three prognostic factors: 1) grade of malignancy (slow growth, 1 point; moderate growth, 2 points; rapid growth, 4 points), 2) visceral metastases (no metastasis, 0 points; treatable, 2 points: untreatable, 4 points), and 3) bone metastases (solitary or isolated, 1 point; multiple, 2 points). These three factors were added together to give a prognostic score between 2-10. The treatment goal for each patient was set according to this prognostic score. The strategy for each patient was decided along with the treatment goal: a prognostic score of 2-3 points suggested a wide or marginal excision for long-term local control; 4-5 points indicated marginal or intralesional excision for middle-term local control; 6-7 points justified palliative surgery for short-term palliation; and 8-10 points indicated nonoperative supportive care. Sixty-one patients were treated prospectively according to this surgical strategy between 1993-1996 (phase 2). The extent of the spinal metastases was stratified using the surgical classification of spinal tumors, and technically appropriate and feasible surgery was performed, such as en bloc spondylectomy, piecemeal thorough excision, curettage, or palliative surgery.

RESULTS

The mean survival time of the 28 patients treated with wide or marginal excision was 38.2 months (26 had successful local control). The mean survival time of the 13 patients treated with intralesional excision was 21.5 months (nine had successful local control). The mean survival time of the 11 patients treated with palliative surgery and stabilization was 10.1 months (eight had successful local control). The mean survival time of the patients with terminal care was 5.3 months.

CONCLUSIONS

A new surgical strategy for spinal metastases based on the prognostic scoring system is proposed. This strategy provides appropriate guidelines for treatment in all patients with spinal metastases.