Lily McLaughlin

Short-segment percutaneous pedicle screw fixation with cement augmentation for tumor-induced spinal instability

BACKGROUND CONTEXT Pathologic vertebral compression fractures (VCFs) represent a major source of morbidity and diminished quality of life in the spinal oncology population. Procedures with low morbidity that effectively treat patients with pathologic fractures are especially important in the cancer population where life expectancy is limited. Vertebroplasty and kyphoplasty are often not effective for mechanically unstable pathologic fractures extending into the pedicle and facet joints. Combination of cement augmentation and percutaneous instrumented stabilization represents a minimally invasive treatment option that does not delay radiation and systemic therapy. PURPOSE The objective of the study was to evaluate the safety and efficacy of cement-augmented short-segment percutaneous posterolateral instrumentation for tumor-associated VCF with pedicle and joint involvement. METHODS Forty-four consecutive patients underwent cement-augmented percutaneous spinal fixation for unstable tumors between 2011 and 2014. Retrospective analysis of prospectively collected data, including visual analog pain scale (VAS) response score and procedural complications, was performed. RESULTS Patients with a median composite Spinal Instability Neoplastic Scale score of 10 (range=8-15) were treated with constructs spanning one to four disk spaces (median of two spaces, constituting 84% of all cases). The proportion of patients with severe pain decreased from 86% preoperatively to 0%; 65% of patients reported no referable instability pain postoperatively. There was one adjacent-level fracture responsive to kyphoplasty, and one case of asymptomatic screw pullout. Two patients subsequently required decompression in the setting of disease progression despite radiation; there was no perioperative morbidity. CONCLUSIONS Percutaneous cement-augmented posterolateral spinal fixation is a safe and effective option for palliation of appropriately selected mechanically unstable VCF that extends into pedicle and/or joint.

Five-Year Outcomes of High-Dose Single-Fraction Spinal Stereotactic Radiosurgery

PURPOSE To characterize local tumor control and toxicity risk in very long-term survivors (>5 years) after high-dose spinal image guided, intensity modulated radiation therapy delivered as single-dose stereotactic radiosurgery (SRS). Previously published spinal SRS outcome analyses have included a heterogeneous population of cancer patients, mostly with short survival. This is the first study reporting the long-term tumor control and toxicity profiles after high-dose single-fraction spinal SRS. METHODS AND MATERIALS The study population included all patients treated from June 2004 to July 2009 with single-fraction spinal SRS (dose 24 Gy) who had survived at least 5 years after treatment. The endpoints examined included disease progression, surgical or radiation retreatment, in-field fracture development, and radiation-associated toxicity, scored using the Radiation Therapy Oncology Group radiation morbidity scoring criteria and the Common Terminology Criteria for Adverse Events, version 4.0. Local control and fracture development were assessed using Kaplan-Meier analysis. RESULTS Of 278 patients, 31 (11.1%), with 36 segments treated for spinal tumors, survived at least 5 years after treatment and were followed up radiographically and clinically for a median of 6.1 years (maximum 102 months). The histopathologic findings for the 5-year survivors included radiation-resistant metastases in 58%, radiation-sensitive metastases in 22%, and primary bone tumors in 19%. In this selected cohort, 3 treatment failures occurred at a median of 48.6 months, including 2 recurrences in the radiation field and 1 patient with demonstrated progression at the treatment margins. Ten lesions (27.8%) were associated with acute grade 1 cutaneous or gastrointestinal toxicity. Delayed toxicity ≥ 3 months after treatment included 8 cases (22.2%) of mild neuropathy, 2 (5.6%) of gastrointestinal discomfort, 8 (22.2%) of dermatitides, and 3 (8.3%) of myalgias/myositis. Thirteen treated levels (36.1%) in 12 patients demonstrated progressive vertebral body collapse or endplate fractures at a median of 25.7 months (range 11.6-76.0), of which 5 (14%) became symptomatic and subsequently required percutaneous cement augmentation or surgery. CONCLUSIONS In the longest-term series to date, high-dose single-fraction spinal SRS retained an excellent safety profile among long-term survivors (>5 years).

The impact of histology and delivered dose on local control of spinal metastases treated with stereotactic radiosurgery.

OBJECTIVE An analysis of factors contributing to durable radiographic control of spinal metastases was undertaken, drawing from a large single-institution database in an attempt to elucidate indications and dose requirements for successful treatment. METHODS All patients treated at a single institution with stereotactic radiosurgery (SRS) of the spine as first-line therapy were assessed for local progression of the treated site, defined as radiographic enlargement of the treated tumor and/or biopsy-proven evidence of active tumor cells. All patients were followed with CT, PET, or MR imaging every 3-6 months until death. Treatment decisions were made by a multidisciplinary team of radiation oncologists, neurosurgeons, and neuroradiologists. Target volumes were defined according to the international consensus guidelines and were reviewed in a multidisciplinary conference. Image-guided techniques and intensity modulation were used for every case. The tumors histological type, gross tumor volume (GTV), dose that covers 95% of the GTV (GTV D95), percentage of GTV covered by 95% of the prescribed dose (GTV V95), planning target volume (PTV), dose that covers 95% of the PTV (PTV D95), and percentage of PTV covered by 95% of the prescribed dose (PTV V95) were analyzed for significance in relation to local control, based on time to local progression. RESULTS A total of 811 lesions were treated in 657 patients between 2003 and 2015 at a single institution. The mean follow-up and overall survival for the entire cohort was 26.9 months (range 2-141 months). A total of 28 lesions progressed and the mean time to failure was 26 months (range 9.7-57 months). The median prescribed dose was 2400 cGy (range 1600-2600 cGy). Both GTV D95 and PTV D95 were highly significantly associated with local failure in univariate analysis, but GTV and PTV and histological type did not reach statistical significance. The median GTV D95 for the cohort equal to or above the GTV D95 1830 cGy cut point (high dose) was 2356 cGy, and it was 1709 cGy for the cohort of patients who received less than 1830 cGy (low dose). In terms of PTV D95, the median dose for those equal to or above the cut point of 1740 cGy (high dose) was 2233 cGy, versus 1644 cGy for those lesions below the PTV D95 cut point of 1740 cGy (low dose). CONCLUSIONS High-dose single-session SRS provides durable long-term control, regardless of the histological findings or tumor size. In this analysis, the only significant factors predictive of local control were related to the actual dose of radiation given. Although the target volumes were well treated with the intended dose, those lesions irradiated to higher doses (median GTV D95 2356 cGy, minimum 1830 cGy) had a significantly higher probability of durable local control than those treated with lower doses (median PTV D95 2232 cGy, minimum of 1740 cGy) (p < 0.001). Patients in the high-dose cohort had a 2% cumulative rate of local failure. Histological findings were not associated with local failure, suggesting that radioresistant histological types benefit in particular from radiosurgery. For patients with a favorable prognosis, a higher dose of SRS is important for long-term outcomes.

Frequency of symptomatic vertebral body compression fractures requiring intervention following single-fraction stereotactic radiosurgery for spinal metastases

OBJECTIVE The purpose of this study was to determine the rate of symptomatic vertebral body compression fractures (VCFs) requiring kyphoplasty or surgery in patients treated with 24-Gy single-fraction stereotactic radiosurgery (SRS). METHODS This retrospective analysis included all patients who had been treated with 24-Gy, single-fraction, image-guided intensity-modulated radiation therapy for histologically confirmed solid tumor metastases over an 8-year period (2005-2013) at Memorial Sloan Kettering Cancer Center. Charts and imaging studies were reviewed for post-SRS kyphoplasty or surgery for mechanical instability. A Spinal Instability Neoplastic Score (SINS) was calculated for each patient both at the time of SRS and at the time of intervention for VCF. RESULTS Three hundred twenty-three patients who had undergone single-fraction SRS between C-1 and L-5 were included in this analysis. The cumulative incidence of VCF 5 years after SRS was 7.2% (95% CI 4.1-10.2), whereas that of death following SRS at the same time point was 82.5% (95% CI 77.5-87.4). Twenty-six patients with 36 SRS-treated levels progressed to symptomatic VCF requiring treatment with kyphoplasty (6 patients), surgery (10 patients), or both (10 patients). The median time to symptomatic VCF was 13 months. Seven patients developed VCF at 11 levels adjacent to the SRS-treated level. Fractured levels had no evidence of tumor progression. The median SINS changed from 6.5 at SRS (interquartile range [IQR] 4.3-8.8) to 11.5 at stabilization (IQR 9-13). In patients without prior stabilization at the level of SRS, there was an association between the SINS and the time to fracture. CONCLUSIONS Five years after ablative single-fraction SRS to spinal lesions, the cumulative incidence of symptomatic VCF at the treated level without tumor recurrence was 7.2%. Higher SINSs at the time of SRS correlated with earlier fractures.

The SORG nomogram accurately predicts 3- and 12-months survival for operable spine metastatic disease: External validation

Externally validate the SORG12 nomogram and SORG classic algorithm at estimating survival in patients with spine metastatic disease, and compare predictive accuracy with other survival algorithms.

Clinical outcomes following resection of giant spinal schwannomas: a case series of 32 patients

OBJECTIVE The objective of this study was to review clinical outcomes following resection of giant spinal schwannomas. METHODS The authors conducted a retrospective review of a case series of patients with giant spinal schwannomas at a tertiary cancer hospital. RESULTS Thirty-two patients with giant spinal schwannomas underwent surgery between September 1998 and May 2013. Tumor size ranged from 2.5 cm to 14.6 cm with a median size of 5.8 cm. There were 9 females (28.1%) and 23 males (71.9%), and the median age was 47 years (range 23-83 years). The median follow-up duration was 36.0 months (range 12.2-132.4 months). Three patients (9.4%) experienced recurrence and required further treatment. All recurrences developed following subtotal resection (STR) of cellular or melanotic schwannoma. There were 3 melanotic (9.4%) and 6 cellular (18.8%) schwannomas included in this study. Among these histological variants, a 33.3% recurrence rate was noted. In 1 case of melanotic schwannoma, malignant transformation occurred. No recurrence occurred following gross-total resection (GTR) or when a fibrous capsule remained due to its adherence to functional nerve roots. CONCLUSIONS Resection is the treatment of choice for symptomatic or growing giant schwannomas, frequently requiring anterior or combined approaches, with the goals of symptom relief and prevention of recurrence. In this series, tumors that underwent GTR, or where only capsule remained, did not recur. Only melanotic and cellular schwannomas that underwent STR recurred.

Incidence and risk factors for preoperative deep venous thrombosis in 314 consecutive patients undergoing surgery for spinal metastasis

OBJECTIVE The authors of this study aimed to identify the incidence of and risk factors for preoperative deep venous thrombosis (DVT) in patients undergoing surgical treatment for spinal metastases. METHODS Univariate analysis of patient age, sex, ethnicity, laboratory values, comorbidities, preoperative ambulatory status, histopathological classification, spinal level, and surgical details was performed. Factors significantly associated with DVT univariately were entered into a multivariate logistic regression model. RESULTS The authors identified 314 patients, of whom 232 (73.9%) were screened preoperatively for a DVT. Of those screened, 22 (9.48%) were diagnosed with a DVT. The screened patients were older (median 62 vs 55 years, p = 0.0008), but otherwise similar in baseline characteristics. Nonambulatory status, previous history of DVT, lower partial thromboplastin time, and lower hemoglobin level were statistically significant and independent factors associated with positive results of screening for a DVT. Results of screening were positive in only 6.4% of ambulatory patients in contrast to 24.4% of nonambulatory patients, yielding an odds ratio of 4.73 (95% CI 1.88-11.90). All of the patients who had positive screening results underwent preoperative placement of an inferior vena cava filter. CONCLUSIONS Patients requiring surgery for spinal metastases represent a population with unique risks for venous thromboembolism. This study showed a 9.48% incidence of DVT in patients screened preoperatively. The highest rates of preoperative DVT were identified in nonambulatory patients, who were found to have a 4-fold increase in the likelihood of harboring a DVT. Understanding the preoperative thrombotic status may provide an opportunity for early intervention and risk stratification in this critically ill population.

Patient-reported outcomes after surgical stabilization of spinal tumors: symptom-based validation of the Spinal Instability Neoplastic Score (SINS) and surgery

BACKGROUND CONTEXT Neoplastic spinal instability is movement-related pain or neurologic compromise under physiologic loads with the Spinal Instability Neoplastic Score (SINS) developed to facilitate diagnosis. There is a paucity of evidence that mechanical instability correlates with patient-reported symptoms and that surgical stabilization significantly improves these patient-reported outcomes (PROs). PURPOSE The objective of this study was to determine if SINS correlates with patient-reported preoperative pain and disability, and if surgical stabilization significantly improves PRO. STUDY DESIGN A single-institution prospective cohort study was carried out. PATIENT SAMPLE A total of 131 patients who underwent stabilization for metastatic spinal tumor treatment between July 2014 and August 2016 were included. OUTCOMES MEASURES Preoperative baseline and mean difference in perioperative PROs as assessed by the Brief Pain Inventory (BPI) and MD Anderson Symptom Inventory (MDASI) were the outcome measures. METHODS The SINS was analyzed as a continuous, ordinal, and categorical variable (Stable: 0-6, Indeterminate: 7-12, Unstable: 13-18). Statistical analysis was performed using Spearman rank coefficient (rho), the Kruskal-Wallis test, and an extension of the Cochran-Armitage trend test. The SINS and association between the mean differences in post- and preoperative PRO scores was analyzed using the Wilcoxon signed-rank test. RESULTS There was a statistically significant positive correlation between increasing SINS and severity of preoperative pain with BPI average pain (rho=0.20; p=.03) and MDASI pain (rho=0.19; p=.03). Increasing SINS correlated with severity of preoperative disability with BPI walking (rho=0.19; p=.04), MDASI activity (rho=0.24; p=.006), and MDASI walking (rho=0.20; p=.03). Similar associations were noted when SINS was analyzed as an ordinal categorical variable. Stabilization significantly improved nearly all PRO measures for patients with indeterminate and unstable SINS. Significant correlations persisted when controlling for neurologic status and were not affected based on the technique of surgical stabilization used. CONCLUSIONS Patient-related outcome-based validation of SINS confirms this scoring system for diagnosing neoplastic spinal instability and provides surgeons with a tool to determine which patients will benefit from stabilization. Surgical stabilization of cancer patients with SINS consistent with mechanical instability provides significant reduction in pain and improves patient mobility independent of neurologic status and stabilization technique.

Minimal Access Surgery for Spinal Metastases: Prospective Evaluation of a Treatment Algorithm Using Patient-Reported Outcomes

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.

Metastases of spinal myxopapillary ependymoma: unique characteristics and clinical management

OBJECTIVE Myxopapillary ependymoma is a benign WHO Grade I tumor most commonly located in the conus-cauda equina region of the spine. Although this tumor is defined by an overall excellent survival, dissemination throughout the whole neuraxis occurs frequently. The current study evaluated the clinical characteristics and significance of myxopapillary ependymoma metastases. METHODS Patients who underwent surgery from 2005 to 2015 for treatment of spinal myxopapillary ependymoma were included in the study. Charts were reviewed for primary tumor symptoms and initial treatment, local recurrence, response to salvage therapy, and presence and behavior of distant metastases. RESULTS Nineteen patients with spinal myxopapillary ependymoma were included in the study (52.6% female). The median age at first diagnosis was 32 years old (range 9-58 years old), and 26.3% were ≤ 18 years old. The median follow-up of all included patients was 48 months (range 6-456 months). Of the primary tumors, 84.2% were located in the lower thoracic or upper lumbar spine, spanning 1-3 levels in 94.7%. All patients underwent surgery for initial treatment: in 78.9% a gross-total resection (GTR) was achieved, with adjuvant radiation therapy (RT) in 20%. Of the 21.2% who underwent a subtotal resection (STR), 75% underwent postoperative RT. Tumor progression was noted in 26.3% of patients after a median 36-month follow-up (range 12-240 months). In 57.9% of patients, distant metastases were found, of which 36.4% were present at initial diagnosis. Further metastases occurred within a median of 20 months (range 2-360 months). Following a diagnosis of metastatic tumor, 72.7% did not show progression and no symptoms were observed during a median follow-up of 36 months (range 6-216 months). Metastases occurred in all parts of the neuroaxis, but were principally localized in the thoracic and sacral spine in 38.9% and 33.3%, respectively; the brain was involved in 11.1%. In 54.5%, more than 1 level was affected. Overall survival was 100% with an excellent clinical and neurological outcome in 78.9% of cases. CONCLUSIONS Metastatic dissemination within the CNS can be observed in many patients with myxopapillary ependymoma. GTR of the primary tumor should be the primary treatment goal, and additional RT is recommended after STR. For distant metastases of myxopapillary ependymoma without clinical manifestation, close clinical and MRI follow-up represents a sufficient strategy because most of the metastases remain asymptomatic and do not show progression over time. Additional resection or irradiation as salvage therapy would be recommended if metastases become symptomatic.