Outcomes in the radiosurgical management of metastatic spine disease

The Impact of the COVID-19 Pandemic on the Presentation of Patients With Spinal Metastases

STUDY DESIGN

Retrospective review.

OBJECTIVE

The aim was to determine if preoperative spinal instability neoplastic scores (SINSs) and Tokuhashi prognostication scores differed in patients receiving surgical care before and during the coronavirus disease-2019 (COVID-19) pandemic.

SUMMARY OF BACKGROUND DATA

The COVID-19 pandemic has caused delays in scheduling nonemergent surgeries. Delay in presentation and/or surgical treatment for oncology patients with metastatic spinal disease could result in progression of the disease, which can complicate surgical care and worsen patient outcomes.

MATERIALS AND METHODS

Retrospective review of electronic medical records between March 1, 2019 and March 1, 2021 at a tertiary medical center was performed to identify patients who underwent surgery for metastatic spine disease. Primary spinal tumors were excluded. Patients were separated into two groups base on their surgery date: before the COVID-19 pandemic (March 1, 2019-February 29, 2020) and during the COVID-19 pandemic (March 1, 2020-March 1, 2021). Primary outcomes included SINS and Tokuhashi scores. A variety of statistical tests were performed to compare the groups.

RESULTS

Fifty-two patients who underwent surgery before the COVID-19 pandemic were compared to 41 patients who underwent surgery during the COVID-19 pandemic. There was a significant difference between the before and during groups with respect to SINS (9.31±2.39 vs . 11.00±2.74, P =0.002) and Tokuhashi scores (9.27±2.35 vs . 7.88±2.85, P =0.012). Linear regression demonstrated time of surgery (before or during COVID-19 restrictions) was a significant predictor of SINS (β=1.55, 95% CI: 0.42-2.62, P =0.005) and Tokuhashi scores (β=-1.41, 95% CI: -2.49 to -0.34, P =0.010).

CONCLUSIONS

Patients with metastatic spinal disease who underwent surgery during the COVID-19 pandemic had higher SINS, lower Tokuhashi scores and similar Skeletal Oncology Research Group scores compared to patients who underwent surgery before the pandemic. This suggests the pandemic has impacted the instability of disease at presentation in patients with spinal metastases, but has not impacted surgical prognosis, as there were no differences in Skeletal Oncology Research Group scores and the difference in Tokuhashi scores is most likely not clinically significant.

Risk Factors for Radiotherapy Failure in the Treatment of Spinal Metastases

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To build a predictive model for risk factors for failure of radiation therapy, hypothesizing a higher SINS would correlate with failure.

METHODS

Patients with spinal metastasis being treated with radiation at a tertiary care academic center between September 2014 and October 2018 were identified. The primary outcome measure was radiation therapy failure as defined by persistent pain, need for re-irradiation, or surgical intervention. Risk factors were primary tumor type, Karnofsky and ECOG scores, time to treatment, biologically effective dose (BED) calculations using α/β ratio = 10, and radiation modality. A logistic regression was used to construct a prediction model for radiation therapy failure.

RESULTS

One hundred and seventy patients were included. Median follow up was 91.5 days. Forty-three patients failed radiation therapy. Of those patients, 10 required repeat radiation and 7 underwent surgery. Thirty-six patients reported no pain relief, including some that required re-irradiation and surgery. Total SINS score for those who failed reduction therapy was <7 for 27 patients (62.8%), between 7-12 for 14 patients (32.6%), and >12 for 2 patients (4.6%). In the final prediction model, BED (OR .451 for BED > 43 compared to BED ≤ 43; P = .174), Karnofksy score (OR .736 for every 10 unit increase in Karnofksy score; P = .008), and gender (OR 2.147 for male compared to female; P = .053) are associated with risk of radiation failure (AUC .695). A statistically significant association between SINS score and radiation therapy failure was not found.

CONCLUSIONS

In the multivariable model, BED ≤ 43, lower Karnofksy score, and male gender are predictive for radiotherapy failure. SINS score was among the candidate risk factors included in multivariable model building procedure, but it was not selected in the final model.

LEVEL OF EVIDENCE

Prognostic level III.

Can the Unipedicular Approach Replace Bipedicular Percutaneous Balloon Kyphoplasty for the Management of Metastatic Vertebral Lesions?

RATIONALE AND OBJECTIVES

To compare the clinical and radiographic results of bipedicular and unipedicular approaches(UPK and BPK) in the management of metastatic vertebral lesions MATERIALS AND METHODS: Eighty-two patients with 159 metastatic vertebral lesions who underwent UPK(25 cases, 69 lesions) or BPK(57 cases, 90 lesions) were retrospectively evaluated. Clinical results were assessed mainly depending on the Visual Analogue Scale(VAS) score, Oswestry Disability Index(ODI) and Quality of Life(QoL). Radiographic outcomes were evaluated primarily on the basis of bone cement distribution and changes in vertebral body height(VBH). Major and minor complications were systematically evaluated and compared to assess the safety of the 2 procedures.

RESULTS

No statistically significant differences were observed in age, sex, types of lesions, location of lesions, posterior vertebral body and/or pedicle involvement, percentage of vertebra invasion between the groups(p=0.17-0.83). The radiographic parameter VBH was similarly improved in both groups(p=0.26-0.93). There was a significant improvement in the clinical parameters VAS score, ODI, and QoL at each follow-up examination compared with the preoperative results(p<0.001). Significant improvement was observed in the VBH at each follow-up point(p<0.05) compared to pre-procedure. UPK was superior to BPK in terms of the operative duration(p<0.001), cement volume(p=0.004), and surgical complications(p=0.04).

CONCLUSION

Both UPK and BPK resulted in similar clinical and radiographic outcomes in patients with metastatic vertebral lesions. The UPK had advantages including a shorter operation and lower cement volume than the BPK, which may have played an important role in reducing the incidence of complications. UPK can replace BPK in the treatment of metastatic vertebral lesions.

Clinical analysis of percutaneous kyphoplasty for spinal metastases in older adults with comorbidities

INTRODUCTION

We aimed to investigate the clinical outcomes of percutaneous kyphoplasty (PKP) for spinal metastases in older adult patients with comorbidities.

MATERIALS AND METHODS

Ninety-two older adults (age ≥ 60 years) with spinal metastases who underwent 148 PKP procedures were retrospectively analyzed. Tokuhashi scores, Tomita scores, age-adjusted Charlson Comorbidity Index (aCCI) scores, and American Society of Anesthesiologists (ASA) scores were evaluated before the procedure. The visual analog scale (VAS), Oswestry Disability Index (ODI), vertebral body height (VBH), and quality of life (QoL) were used to assess the efficacy of the procedure. Clinical safety was evaluated based on periprocedural complications.

RESULTS

Tokuhashi scores and Tomita scores were 7.3 ± 4.0 and 5.8 ± 2.1, respectively. Excluding cancer-related factors, twelve patients (13.0%) had aCCI scores ≥4. Forty-three patients (46.7%) had ASA status ≥ III. Compared to preoperative status, average VAS scores, ODI scores, VBH variation, and QoL scores significantly improved at each follow-up examination point after PKP (p < 0.001). No major complications occurred, nor was there decompensation of comorbidities in the perioperative period. Seventeen segments (11.5%) of twelve patients (13.0%) suffered bone cement leakage. Among them, one patient suffered intercostal neuralgia cured by steroid injection, and the other patient suffered hyperesthesia, which disappeared after taking gabapentin (0.3 g, bid) for five weeks. Another minor complication of local hematoma occurred in one patient, which spontaneously resolved without surgical intervention.

DISCUSSION

PKP serves as a safe approach to provide significant pain relief, vertebral body height restoration, and QoL improvements for spinal metastases in older adults, independent of underlying disease.

Single and multi-fraction spine stereotactic body radiation therapy and the risk of radiation induced myelopathy

Purpose

This study reports on the risk of radiation-induced myelitis (RM) of the spinal cord from a large single-institutional experience with 1 to 5 fraction stereotactic body radiation therapy (SBRT) to the spine.

Methods and Materials

A retrospective review of patients who received spine SBRT to a radiation naïve level at or above the conus medullaris between 2007 and 2019 was performed. Local failure determination was based on SPIne response assessment in Neuro-Oncology criteria. RM was defined as neurologic symptoms consistent with the segment of cord irradiated in the absence of neoplastic disease recurrence and graded by Common Toxicity Criteria for Adverse Events, version 4.0. Rates of adverse events were estimated and dose-volume statistics from delivered treatment plans were extracted for the planning target volumes and spinal cord.

Results

A total of 353 lesions in 277 patients were identified that met the specified criteria, for which 270, 70, and 13 lesions received 1-, 3-, and 5-fraction treatments, respectively, with a median follow-up of 46 months (95% confidence interval [CI], 41-52 months) for all surviving patients. The median overall survival was 33.0 months (95% CI, 29-43). The median D0.03cc to the spinal cord was 11.7 Gy (interquartile range [IQR], 10.5-12.4), 16.7 Gy (IQR, 12.8-20.6), and 26.0 Gy (IQR, 24.1-28.1), for 1-, 3-, 5-fractions. Using an a/b = 2Gy for the spinal cord, the median single-fraction equivalent-dose (SFED₂) was 11.7 Gy (IQR, 10.2-12.5 Gy) and the normalized biological equivalent dose (nBED_2/2) was 19.9 Gy (IQR, 15.4-22.8 Gy). One patient experienced grade 2 RM after a single-fraction treatment. The cumulative probability of RM was 0.3% (95% CI, 0%-2%).

Conclusions

Spine SBRT is safe while limiting the spinal cord (as defined on treatment planning magnetic resonance imaging or computed tomography myelogram) D0.03cc to less than 14 Gy, 21.9 Gy, and 30 Gy, for 1, 3, and 5-fractions, consistent with standard guidelines.

Integrated Custom Composite Polyetheretherketone/Carbon fiber (PEEK/CF) Vertebral Body Replacement (VBR) in the Treatment of Bone Tumors of the Spine: A Preliminary Report From a Multicenter Study

STUDY DESIGN

Retrospective, multicenter chart, and radiologic review.

OBJECTIVE

To present the first case series of bone tumors of the spine surgically reconstructed with a new custom, fully radiolucent, polyetheretherketone/carbon fiber (PEEK/CF) vertebral body replacement (VBR) integrated system.

SUMMARY OF BACKGROUND DATA

Surgical resections of spinal tumors result in large defects and local recurrence remains a concern. Current titanium-based implants adversely affects postoperative imaging, directly affects ability to identify tumor recurrence, and for delivery of radiotherapy treatments. PEEK/CF spinal implants allows for improved tumor surveillance, precise pre-radiation Computed Tomography planning, and reduces interference with post-reconstructive adjuvant radiotherapy.

METHOD

Thirteen patients with spinal tumors underwent vertebral body resection and reconstruction with an integrated, fully radiolucent, custom PEEK/CF vertebral body replacement, and radiolucent posterior PEEK/CF screw-rod system and/or radiolucent anterior PEEK/CF plate system. Clinical and radiographic data were tabulated. Need for adjuvant radiotherapy determined based on final tissue histology and extent of surgical margins. Postoperative surveillance imaging were reviewed for local tumor recurrence.

RESULTS

The ability to integrate the PEEK/CF VBR connected to either the posterior screw-rod system, or anterior plate system provided immediate stability. The VBR was placed directly on cancellous vertebral body surface in 46.2% of cases. Loosening of the distal, or proximal, aspect of posterior system was seen in 15.4% of cases. There was no clinical or radiographic evidence of VBR migration and subsidence at latest follow up. Local recurrence occurred in one (7.7%) patient.

CONCLUSION

This is the first series to describe the use of a fully-radiolucent, integrated, PEEK/CF implant system for spinal tumor reconstruction. The use of a PEEK/CF VBR system integrated to either the anterior plate, or posterior screw-rod system is feasible and allows for superior postoperative surveillance imaging and effective delivery of postoperative adjuvant radiotherapy.Level of Evidence: 4.

Clinical efficacy and safety of bone cement combined with radiofrequency ablation in the treatment of spinal metastases

Background

To investigate the clinical efficacy and safety of bone cement combined with radiofrequency ablation (RFA) in the treatment of spinal metastases.

Methods

The medical records of patients with spinal metastatic tumor admitted to our hospital from January 2016 to December 2018 were retrospectively analyzed. Based on different surgical methods, the patients were divided into groups A (treated with RFA combined with bone cement) and B (treated with bone cement only). Group A included 35 patients with 47 segments of diseased vertebral bodies. Group B consisted of 52 patients with 78 vertebral segments. Pain, quality of life score, vertebra height, bone cement leakage, postoperative tumor recurrence, and complications were assessed 3 days and 1 and 6 months after surgery.

Results

All the patients had smooth operation without paraplegia, spinal cord injury, and perioperative death. Visual analogue scales (VAS) and Oswestry Disability Index (ODI) scores of the two groups significantly improved 3 days and 1 month after surgery compared with those before surgery (P < 0.05), but no significant difference was observed between the two groups (P > 0.05). Six months after surgery, the VAS and ODI scores of patients in group A were lower than those in group B, with statistically significant differences (P < 0.05). The postoperative vertebral body height of the two groups significantly increased compared with that before surgery, and the difference was statistically significant (P < 0.05). Meanwhile, no significant difference was observed between the two groups (P > 0.05). Postoperative bone cement permeability in group A was 6.4%, and postoperative tumor recurrence rate was 11.4%. The permeability of bone cement in group B was 20.5%, and the tumor recurrence rate was 30.8%. The bone cement permeability and tumor recurrence rate in group A were lower than those in group B, with statistically significant differences (P < 0.05).

Conclusions

Bone cement combined with RFA for the treatment of spinal metastases can achieve good efficacy, desirable analgesic effect, low incidence of complications, small surgical trauma, and high safety. The proposed method has the value of clinical popularization and application.

A comparison of stereotactic body radiation therapy for metastases to the sacral spine and treatment of the thoracolumbar spine

Background: This study compares the outcomes of stereotactic body radiation therapy (SBRT) for sacral and thoracolumbar spine metastases. Methods: This analysis considered each sacral spine SBRT treatment at a single institution and a cohort of consecutive thoracolumbar treatments. Results: 28 patients with 35 sacral treatments and 41 patients with 49 thoracolumbar treatments were included. Local control was 63% and 90%, respectively. The sacral cohort contained more lesions with ≥2 vertebrae and epidural and paraspinal involvement. Sacral patients had larger treatment volumes, increased rates of subsequent SBRT, decreased propensity for pain improvement, and decreased local control (p=0.02 on Kaplan-Meier analysis). Multivariate analysis demonstrated that PTV > 50 cc and epidural involvement were correlated with decreased local control. No cases had grade ≥3 toxicity. Conclusion: SBRT for sacral spine metastases is a distinct disease process than metastases to the thoracolumbar spine, resulting in lower rates of local control and pain improvement.

Single-Fraction Radiotherapy (SFRT) For Bone Metastases: Patient Selection And Perspectives

Bone metastases are a frequent and important source of morbidity in cancer patients. Stereotactic body radiation therapy (SBRT) is an established treatment option for local control and pain relief of bone metastases, and it is increasingly used as upfront treatment, postoperative consolidation or salvage treatment after prior RT. However, heterogeneity of dose schedules described in literature represents a severe limitation in the definition of the role of SBRT as a standard of care. No consensus is available on the use of single versus multiple fraction SBRT for bone metastases. Advantages of single-fraction SBRT include shorter overall duration of treatment, absence of inter-fraction uncertainty, improved compliance, theoretical increased efficacy, and lower costs. However, caution has been advised due to reports of severe late toxicities, in particular, vertebral collapse fracture (VCF). The aim of this paper is to review dose fractionation and indications for the management of bone metastases using SBRT.