A novel classification system for spinal instability in neoplastic disease: an evidence-based approach and expert consensus from the Spine Oncology Study Group

How effective is a virtual consultation process in facilitating multidisciplinary decision-making for malignant epidural spinal cord compression?

PURPOSE

The purpose of this study was to assess the accuracy of a virtual consultation (VC) process in determining treatment strategy for patients with malignant epidural spinal cord compression (MESCC).

METHODS AND MATERIALS

A prospective clinical database was maintained for patients with MESCC. A virtual consultation process (involving exchange of key predetermined clinical information and diagnostic imaging) facilitated rapid decision-making between oncologists and spinal surgeons. Diagnostic imaging was reviewed retrospectively (by R.R.) for surgical opinions in all patients. The primary outcome was the accuracy of virtual consultation opinion in predicting the final treatment recommendation.

RESULTS

After excluding 20 patients who were referred directly to the spinal surgeon, 125 patients were eligible for virtual consultation. Of the 46 patients who had a VC, surgery was recommended in 28 patients and actually given to 23. A retrospective review revealed that 5/79 patients who did not have a VC would have been considered surgical candidates. The overall accuracy of the virtual consultation process was estimated at 92%.

CONCLUSION

The VC process for MESCC patients provides a reliable means of arriving at a multidisciplinary opinion while minimizing patient transfer. This can potentially shorten treatment decision time and enhance clinical outcomes.

Surgical Management of Metastatic Spinal Tumors

Background

The spine is the most common site of skeletal metastases. The evolution of surgical methods, medical treatment, and radiation therapy has led to improved survival, functional status, and quality of life for patients with cancer. The role of surgery in the treatment of patients with spinal metastases has evolved over time.

Methods

A review of publications describing the role of open surgery and vertebroplasty was performed and the results are summarized.

Results

The treatment goals of spinal metastases include the preservation and restoration of neurologic function and spinal stability. Modern imaging modalities provide accurate methods of tumor diagnosis. A variety of approaches and stabilization techniques are available and should be tailored to the location of the tumor and systemic comorbidities.

Conclusions

As part of multidisciplinary treatment that includes radiation therapy and chemotherapy, surgery provides an effective method of restoration and preservation of neurologic function and spinal stability for patients with metastatic spinal tumors.

Sparing the posterior surgical site when planning radiation therapy for thoracic metastatic spinal disease

BACKGROUND CONTEXT

Most patients with painful spinal metastases are sufficiently palliated by hypofractionated radiotherapy. However, a small group of patients will need surgical intervention to treat symptomatic spinal cord compression and/or gross mechanical instability. Irradiation of a (prospective) surgical area may lead to postsurgery complications, including wound dehiscence, infection, and chronic wound ulcers. Decreasing the radiation dose to the surgical area could reduce radiation-induced toxicity and associated surgical complications.

PURPOSE

To investigate an alternative radiation technique designed to lower the surgical area dose while delivering an adequate target dose and minimal off-target dose.

STUDY DESIGN

Comparison of radiation doses received by various anatomic structures after simulating irradiation with a routine posteroanterior single field (SF) technique and experimental multiple field (MF) technique in a setting of thoracic metastatic spinal disease.

METHODS

The computed tomography (CT) data from six previously treated patients with a total of 10 thoracic spinal metastases were used to plan four radiation schemes (SF8 Gy; SF20 Gy; MF8 Gy; and MF20 Gy). Discrete anatomic structures were defined on CT data, including a posterior surgical area, and after simulation the doses received were calculated and compared for the 8 Gy and 20 Gy techniques.

RESULTS

With the experimental MF technique, a clinically relevant dose could be delivered to the affected vertebra, whereas the dose received at the (prospective) surgical area could be significantly reduced compared with the SF technique. The dose received at the nontarget tissues fell below the threshold level for clinical relevance.

CONCLUSIONS

This radiation planning study showed the feasibility of sparing the surgical area while delivering an adequate dose to affected vertebrae in thoracic metastatic spinal disease.

Vertebral compression fracture risk after stereotactic body radiotherapy for spinal metastases

Object

The aim of this study was to identify potential risk factors for and determine the rate of vertebral compression fracture (VCF) after intensity-modulated, near-simultaneous, CT image–guided stereotactic body radiotherapy (SBRT) for spinal metastases.

Methods

The study group consisted of 123 vertebral bodies (VBs) in 93 patients enrolled in prospective protocols for metastatic disease. Data from these patients were retrospectively analyzed. Stereotactic body radiotherapy consisted of 1, 3, or 5 fractions for overall median doses of 18, 27, and 30 Gy, respectively. Magnetic resonance imaging studies, obtained at baseline and at each follow-up, were evaluated for VCFs, tumor involvement, and radiographic progression. Self-reported average pain levels were scored based on the 11-point (0–10) Brief Pain Inventory both at baseline and at follow-up. Obesity was defined as a body mass index ≥ 30.

Results

The median imaging follow-up was 14.9 months (range 1–71 months). Twenty-five new or progressing fractures (20%) were identified, and the median time to progression was 3 months after SBRT. The most common histologies included renal cancer (36 VBs, 10 fractures, 10 tumor progressions), breast cancer (20 VBs, 0 fractures, 5 tumor progressions), thyroid cancer (14 VBs, 1 fracture, 2 tumor progressions), non–small cell lung cancer (13 VBs, 3 fractures, 3 tumor progressions), and sarcoma (9 VBs, 2 fractures, 2 tumor progressions). Fifteen VBs were treated with kyphoplasty or vertebroplasty after SBRT, with 5 procedures done for preexisting VCFs. Tumor progression was noted in 32 locations (26%) with 5 months' median time to progression. At the time of noted fracture progression there was a trend toward higher average pain scores but no significant change in the median value. Univariate logistic regression showed that an age > 55 years (HR 6.05, 95% CI 2.1–17.47), a preexisting fracture (HR 5.05, 95% CI 1.94–13.16), baseline pain and narcotic use before SBRT (pain: HR 1.31, 95% CI 1.06–1.62; narcotic: HR 2.98, 95% CI 1.17–7.56) and after SBRT (pain: HR 1.34, 95% CI 1.06–1.70; narcotic: HR 3.63, 95% CI 1.41–9.29) were statistically significant predictors of fracture progression. On multivariate analysis an age > 55 years (HR 10.66, 95% CI 2.81–40.36), a preexisting fracture (HR 9.17, 95% CI 2.31–36.43), and baseline pain (HR 1.41, 95% CI 1.05–1.9) were found to be significant risks, whereas obesity (HR 0.02, 95% CI 0–0.2) was protective.

Conclusions

Stereotactic body radiotherapy is associated with a significant risk (20%) of VCF. Risk factors for VCF include an age > 55 years, a preexisting fracture, and baseline pain. These risk factors may aid in the selection of which spinal SBRT patients should be considered for prophylactic vertebral stabilization or augmentation procedures. Clinical trial registration no.: NCT00508443.

Oncologic emergencies: Pathophysiology, presentation, diagnosis, and treatment

Oncologic emergencies can occur at any time during the course of a malignancy, from the presenting symptom to end-stage disease. Although some of these conditions are related to cancer therapy, they are by no means confined to the period of initial diagnosis and active treatment. In the setting of recurrent malignancy, these events can occur years after the surveillance of a cancer patient has been appropriately transferred from a medical oncologist to a primary care provider. As such, awareness of a patient's cancer history and its possible complications forms an important part of any clinician's knowledge base. Prompt identification of and intervention in these emergencies can prolong survival and improve quality of life, even in the setting of terminal illness. This article reviews hypercalcemia, hyponatremia, hypoglycemia, tumor lysis syndrome, cardiac tamponade, superior vena cava syndrome, neutropenic fever, spinal cord compression, increased intracranial pressure, seizures, hyperviscosity syndrome, leukostasis, and airway obstruction in patients with malignancies. Chemotherapeutic emergencies are also addressed.

Early surgical experience with minimally invasive percutaneous approach for patients with metastatic epidural spinal cord compression (MESCC) to poor prognoses

PURPOSE

This study was designed to assess the impact of minimally invasive surgery (MIS) for the treatment of patients with metastatic epidural spinal cord compression (MESCC) and vertebral body fracture, in terms of feasibility, clinical improvement, and morbidity.

METHODS

Twenty-five consecutive patients with diagnosis of MESCC from solid primary tumors were treated between January 2008 and June 2010 at our institution. All patients, after multidisciplinary assessment, were considered with poor prognosis because of their disease's extension and/or other clinical conditions. Mini-invasive percutaneous surgery was performed in all patients followed by radiotherapy within 2 weeks postoperatively. Clinical outcome was evaluated by modified visual analog scale for pain, Frankel Scale for neurologic deficit, and magnetic resonance imaging or computed tomography scan.

RESULTS

Clinical remission of pain was obtained in the vast majority of patients (96%). Improvement of neurological deficit was observed in 22 patients (88%). No major morbidity or perioperative mortality occurred. The average hospital stay was 6 days. Local recurrence occurred in two patients (8%). Median survival was 10 (range, 6-24) months. Overall survival at 1 year was 43%.

CONCLUSIONS

For patients with MESCC and body fracture, with limited life expectancy, minimally invasive spinal surgery followed by radiotherapy, is feasible and provides clinical benefit in most of patients, with low morbidity. We believe that a minimally invasive approach can be an alternative surgical method compared with more aggressive or demanding procedures, which in selected patients with metastatic spinal cord compression with poor prognosis could represent overtreatment.

Spinal instability neoplastic score: an analysis of reliability and validity from the spine oncology study group

PURPOSE

Standardized indications for treatment of tumor-related spinal instability are hampered by the lack of a valid and reliable classification system. The objective of this study was to determine the interobserver reliability, intraobserver reliability, and predictive validity of the Spinal Instability Neoplastic Score (SINS).

METHODS

Clinical and radiographic data from 30 patients with spinal tumors were classified as stable, potentially unstable, and unstable by members of the Spine Oncology Study Group. The median category for each patient case (consensus opinion) was used as the gold standard for predictive validity testing. On two occasions at least 6 weeks apart, each rater also scored each patient using SINS. Each total score was converted into a three-category data field, with 0 to 6 as stable, 7 to 12 as potentially unstable, and 13 to 18 as unstable.

RESULTS

The κ statistics for interobserver reliability were 0.790, 0.841, 0.244, 0.456, 0.462, and 0.492 for the fields of location, pain, bone quality, alignment, vertebral body collapse, and posterolateral involvement, respectively. The κ statistics for intraobserver reliability were 0.806, 0.859, 0.528, 0.614, 0.590, and 0.662 for the same respective fields. Intraclass correlation coefficients for inter- and intraobserver reliability of total SINS score were 0.846 (95% CI, 0.773 to 0.911) and 0.886 (95% CI, 0.868 to 0.902), respectively. The κ statistic for predictive validity was 0.712 (95% CI, 0.676 to 0.766).

CONCLUSION

SINS demonstrated near-perfect inter- and intraobserver reliability in determining three clinically relevant categories of stability. The sensitivity and specificity of SINS for potentially unstable or unstable lesions were 95.7% and 79.5%, respectively.

Anterior construct location following vertebral body metastasis reconstruction through a posterolateral transpedicular approach: does it matter?

Object

The posterolateral transpedicular approach (PTA) is a widely used method for the surgical treatment of vertebral body metastases. It is crucial to understand the optimal location of the anterior graft in terms of sound and durable reconstruction following PTA. The purpose of this study was to investigate whether postoperative construct stability is related to the location of anterior grafts.

Methods

The authors conducted a retrospective review of 45 cases of metastatic spine disease with epidural tumor extension in which patients underwent circumferential decompression and fusion by means of PTA. Mechanical (anterior construct stability), pain (visual analog scale score), and neurological (American Spinal Injury Association scale) outcomes were evaluated and correlated with the anterior graft location (lateral or central) and surgical approach (unilateral or bilateral), number of decompressed levels, types of anterior graft, screw density of posterior fixation (number of screws used divided by the number of pedicles spanned), and kyphotic angle change from the immediate postoperative period to the most recent follow-up.

Results

Seven of 45 constructs were judged unstable—5 with a lateral location of the anterior graft and 2 with a central location.

The anterior graft was located laterally in 31 cases (69%), centrally in 11 (24%), and bilaterally in 3 (7%). A unilateral approach was used in 33 cases and a bilateral approach in 12. Neither the location of the anterior graft nor the approach had a significant effect on the stability of the reconstructed spine (p > 0.05). There was a significant difference in construct stability between the single-level decompression group (33 patients) and the multiple-level decompression group (12 patients) (p = 0.0001). The types of anterior graft, screw density, and kyphotic angle change were not correlated to the mechanical outcome.

Conclusions

The anterior graft location showed no significant relationship to the final mechanical, pain, and neurological outcomes.