Essential tremor and Parkinson's disease-associated tremor are extremely prevalent within the field of movement disorders. The ventral intermediate (VIM) nucleus of the thalamus has been commonly used as both a neuromodulatory and neuroablative target for the treatment of these forms of tremor. With both deep brain stimulation and Gamma Knife radiosurgery, there is an abundance of literature regarding the surgical planning, targeting, and outcomes of these methodologies. To date, there have been no reports of frameless, linear accelerator (LINAC)-based thalomotomies for tremor. The authors report the case of a patient with tremor-dominant Parkinson's disease, with poor tremor improvement with medication, who was offered LINAC-based thalamotomy. High-resolution 0.9-mm isotropic MR images were obtained, and simulation was performed via CT with 1.5-mm contiguous slices. The VIM thalamic nucleus was determined using diffusion tensor imaging (DTI)-based segmentation on FSL using probabilistic tractography. The supplemental motor and premotor areas were the cortical target masks. The authors centered their isocenter within the region of the DTI-determined target and treated the patient with 140 Gy in a single fraction. The DTI-determined target had coordinates of 14.2 mm lateral and 8.36 mm anterior to the posterior commissure (PC), and 3 mm superior to the anterior commissure (AC)-PC line, which differed by 3.30 mm from the original target determined by anatomical considerations (15.5 mm lateral and 7 mm anterior to the PC, and 0 mm superior to the AC-PC line). There was faint radiographic evidence of lesioning at the 3-month follow-up within the target zone, which continued to consolidate on subsequent scans. The patient experienced continued right upper-extremity resting tremor improvement starting at 10 months until it was completely resolved at 22 months of follow-up. Frameless LINAC-based thalamotomy guided by DTI-based thalamic segmentation is a feasible method for achieving radiosurgical lesions of the VIM thalamus to treat tremor.

Purpose

Stereotactic radiosurgery (SRS) provides a noninvasive treatment modality for patients with medically refractory trigeminal neuralgia. The root entry zone (REZ) has been proposed to be an ideal stereotactic target because it is partially composed of centrally produced myelin, conferring a theoretical increased sensitivity to irradiation as well as increased susceptibility to neurovascular conflict, making it the site in which nociceptive signals likely arise. The aim of this study is to determine if there is a statistically and clinically significant difference in pain relief or facial hypesthesia following SRS based on distance of the stereotactic isocenter from REZ.

Methods and materials

Patients undergoing Novalis radiosurgery for the treatment of trigeminal neuralgia with at least 3 months' follow-up were included in this study. Postoperative outcomes were stratified by Barrow Neurological Institute (BNI) score for pain relief and BNI facial numbness score for facial hypesthesia.

Results

Sixty-seven patients met inclusion criteria and were included in this study. BNI score of I-IIIa was attained in 82% of patients at 3 months and 65% at 1 year following SRS. Distance from isocenter to REZ varied from 0 to 8.6 mm, with a mean of 1.94 ± 1.62 mm. Logistic regression of target-REZ distance against pain relief outcome (patients with score I-IIIa and IIIb-V) was insignificant at 3 months (P = .988), 6 months (P = .925), 9 months (P = .845), and 12 months (P = .547) postoperatively. Furthermore, no significant correlation was found with logistic regression of target-REZ distance with pain relief outcome (patients with score I and score II-IV) (P = .544).

Conclusions

The current analysis suggests that distance from REZ does not correlate with degree of postoperative pain relief or facial hypesthesia; thus, targeting specific regions within the trigeminal nerve in relation to these anatomical characteristics may not afford any advantage from this perspective.

Background context

Osteosarcoma (OGS) and Ewing sarcoma (EWS) are the two classic primary malignant bone tumors. Due to the rarity of these tumors, evidence on demographics, survival determinants, and treatment outcomes for primary disease of the spine are limited and derived from small case series.

Purpose

To use population-level data to determine the epidemiology and prognostic indicators in patients with OGS and EWS of the osseous spine.

Study design/setting

Large-scale retrospective study.

Patient sample

Patients diagnosed with OGS and EWS of the spine in the Surveillance, Epidemiology, and End Results (SEER) registry from 1973 to 2012.

Outcome measures

Overall survival (OS) and disease-specific survival (DSS).

Methods

Two separate queries of the SEER registry were performed to identify patients with OGS and EWS of the osseous spine from 1973-2012. Study variables included age, sex, race, year of diagnosis, tumor size, extent of disease (EOD), and treatment with surgery and/or radiation therapy. Primary outcome was defined as OS and DSS in months. Univariate survival analysis was performed using the Kaplan-Meier method and the log-rank test. Multivariate analysis was performed using Cox proportional hazards regression models.

Results

The search identified 648 patients with primary OGS and 736 patients with primary EWS of the spine from 1973 to 2012. Mean age at diagnosis was 48.1 and 19.9 years for OGS and EWS, respectively, with OGS showing a bimodal distribution. The median OS and DSS were 1.3 and 1.7 years, respectively, for OGS, with OGS in Paget's disease having worse OS (0.7 years) relative to the mean (log-rank p=.006). The median OS and DSS for EWS were 3.9 and 4.3 years, respectively. Multivariate cox regression analysis showed that age (OS p<.001, DSS p<.001), decade of diagnosis (OS p=.049), surgical resection (OS p<.001, DSS p<.001), and EOD (OS p<.001, DSS p<.001) were independent positive prognostic indicators for spinal OGS; radiation therapy predicted worse OS (hazard ratio [HR] 1.48, confidence interval [CI] 1.05-2.10, p=.027) and DSS (HR 1.74, CI 1.13-2.66, p=.012) for OGS. For EWS, age (OS p<.001, DSS p<.001), surgical resection (OS p=.030, DSS p=.046), tumor size (OS p<.001, DSS p<.001), and EOD (OS p<.001, DSS p<.001) were independent determinants of improved survival; radiation therapy trended toward improved survival but did not achieve statistical significance for both OS (HR 0.76, CI 0.54-1.07, p=.113) and DSS (0.76, CI 0.54, 1.08, p=.126).

Conclusions

Age, surgical resection, and EOD are key survival determinants for both OGS and EWS of the spine. Radiation therapy may be associated with worse outcomes in patients with OGS, and is of potential benefit in EWS. Overall prognosis has improved in patients with OGS of the spine over the last four decades.

Background context

Osteosarcoma (OGS) and Ewing sarcoma (EWS) are the two classic primary malignant bone tumors. Due to the rarity of these tumors, evidence on demographics, survival determinants, and treatment outcomes for primary disease of the spine are limited and derived from small case series.

Purpose

To use population-level data to determine the epidemiology and prognostic indicators in patients with OGS and EWS of the osseous spine.

Study design/setting

Large-scale retrospective study.

Patient sample

Patients diagnosed with OGS and EWS of the spine in the Surveillance, Epidemiology, and End Results (SEER) registry from 1973 to 2012.

Outcome measures

Overall survival (OS) and disease-specific survival (DSS).

Methods

Two separate queries of the SEER registry were performed to identify patients with OGS and EWS of the osseous spine from 1973-2012. Study variables included age, sex, race, year of diagnosis, tumor size, extent of disease (EOD), and treatment with surgery and/or radiation therapy. Primary outcome was defined as OS and DSS in months. Univariate survival analysis was performed using the Kaplan-Meier method and the log-rank test. Multivariate analysis was performed using Cox proportional hazards regression models.

Results

The search identified 648 patients with primary OGS and 736 patients with primary EWS of the spine from 1973 to 2012. Mean age at diagnosis was 48.1 and 19.9 years for OGS and EWS, respectively, with OGS showing a bimodal distribution. The median OS and DSS were 1.3 and 1.7 years, respectively, for OGS, with OGS in Paget's disease having worse OS (0.7 years) relative to the mean (log-rank p=.006). The median OS and DSS for EWS were 3.9 and 4.3 years, respectively. Multivariate cox regression analysis showed that age (OS p<.001, DSS p<.001), decade of diagnosis (OS p=.049), surgical resection (OS p<.001, DSS p<.001), and EOD (OS p<.001, DSS p<.001) were independent positive prognostic indicators for spinal OGS; radiation therapy predicted worse OS (hazard ratio [HR] 1.48, confidence interval [CI] 1.05-2.10, p=.027) and DSS (HR 1.74, CI 1.13-2.66, p=.012) for OGS. For EWS, age (OS p<.001, DSS p<.001), surgical resection (OS p=.030, DSS p=.046), tumor size (OS p<.001, DSS p<.001), and EOD (OS p<.001, DSS p<.001) were independent determinants of improved survival; radiation therapy trended toward improved survival but did not achieve statistical significance for both OS (HR 0.76, CI 0.54-1.07, p=.113) and DSS (0.76, CI 0.54, 1.08, p=.126).

Conclusions

Age, surgical resection, and EOD are key survival determinants for both OGS and EWS of the spine. Radiation therapy may be associated with worse outcomes in patients with OGS, and is of potential benefit in EWS. Overall prognosis has improved in patients with OGS of the spine over the last four decades.

Study design

Retrospective analysis.

Objective

To determine the epidemiology and prognostic indicators in patients with chondrosarcoma of the osseous spine.

Summary of background data

Chondrosarcoma of the spine is rare, with limited data on its epidemiology, clinicopathologic features, and treatment outcomes. Therapy centers on complete en bloc resection with radiotherapy reserved for subtotal resection or advanced disease.

Methods

The Surveillance, Epidemiology, and End Results Registry was queried for patients with chondrosarcoma of the osseous spine from 1973 to 2012. Study variables included age, sex, race, year of diagnosis, size, grade, extent of disease, and treatment modality.

Results

The search identified 973 cases of spinal chondrosarcoma. Mean age at diagnosis was 51.6 years, and 627% of patients were males. Surgical resection and radiotherapy were performed in 75.2% and 21.3% of cases, respectively. Kaplan-Meier analysis demonstrated overall survival (OS) and disease-specific survival (DSS) of 53% and 64%, respectively, at 5 years. Multivariate Cox regression analysis showed that age (OS, P < 0.001; DSS, P = 0.007), grade (OS, P < 0.001; DSS, P < 0.001), surgical resection (OS, P < 0.001; DSS, P < 0.001), and extent of disease (OS, P < 0.001; DSS, P < 0.001) were independent survival determinants; tumor size was an independent predictor of OS (P = 0.006). For confined disease, age (P = 0.013), decade of diagnosis (P = 0.023), and surgery (P = 0.017) were independent determinants of OS. For locally invasive disease, grade (OS, P < 0.001; DSS, P = 0.003), surgery (OS, P = 0.013; DSS, P = 0.046), and size (OS, P = 0.001, DSS, P = 0.002) were independent determinants of OS and DSS. Radiotherapy was an independent indicator of worse OS for both confined (P = 0.004) and locally invasive disease (P = 0.002). For metastatic disease, grade (OS, P = 0.021; DSS, P = 0.012) and surgery (OS, P = 0.007; DSS, P = 0.004) were survival determinants for both OS and DSS, whereas radiotherapy predicted improved OS (P = 0.039).

Conclusion

Surgical resection confers survival benefit in patients with chondrosarcoma of the spine independent of extent of disease. Radiotherapy improves survival in patients with metastatic disease and worsens outcomes in patients with confined and locally invasive disease.

Level of evidence

4.

Study design

Retrospective analysis.

Objective

To determine the epidemiology and prognostic indicators in patients with chondrosarcoma of the osseous spine.

Summary of background data

Chondrosarcoma of the spine is rare, with limited data on its epidemiology, clinicopathologic features, and treatment outcomes. Therapy centers on complete en bloc resection with radiotherapy reserved for subtotal resection or advanced disease.

Methods

The Surveillance, Epidemiology, and End Results Registry was queried for patients with chondrosarcoma of the osseous spine from 1973 to 2012. Study variables included age, sex, race, year of diagnosis, size, grade, extent of disease, and treatment modality.

Results

The search identified 973 cases of spinal chondrosarcoma. Mean age at diagnosis was 51.6 years, and 627% of patients were males. Surgical resection and radiotherapy were performed in 75.2% and 21.3% of cases, respectively. Kaplan-Meier analysis demonstrated overall survival (OS) and disease-specific survival (DSS) of 53% and 64%, respectively, at 5 years. Multivariate Cox regression analysis showed that age (OS, P < 0.001; DSS, P = 0.007), grade (OS, P < 0.001; DSS, P < 0.001), surgical resection (OS, P < 0.001; DSS, P < 0.001), and extent of disease (OS, P < 0.001; DSS, P < 0.001) were independent survival determinants; tumor size was an independent predictor of OS (P = 0.006). For confined disease, age (P = 0.013), decade of diagnosis (P = 0.023), and surgery (P = 0.017) were independent determinants of OS. For locally invasive disease, grade (OS, P < 0.001; DSS, P = 0.003), surgery (OS, P = 0.013; DSS, P = 0.046), and size (OS, P = 0.001, DSS, P = 0.002) were independent determinants of OS and DSS. Radiotherapy was an independent indicator of worse OS for both confined (P = 0.004) and locally invasive disease (P = 0.002). For metastatic disease, grade (OS, P = 0.021; DSS, P = 0.012) and surgery (OS, P = 0.007; DSS, P = 0.004) were survival determinants for both OS and DSS, whereas radiotherapy predicted improved OS (P = 0.039).

Conclusion

Surgical resection confers survival benefit in patients with chondrosarcoma of the spine independent of extent of disease. Radiotherapy improves survival in patients with metastatic disease and worsens outcomes in patients with confined and locally invasive disease.

Level of evidence

4.