Treatment outcomes of stereotactic body radiation therapy for primary and metastatic sarcoma of the spine.

PURPOSE: This study evaluated the treatment outcomes of spine stereotactic body radiation therapy (SBRT) in sarcoma patients. MATERIALS AND METHODS: A total of 44 sarcoma patients and 75 spinal lesions (6 primary tumors, 69 metastatic tumors) treated with SBRT were retrospectively reviewed between 2006 and 2017. The median radiation dose was 33 Gy (range, 18-45 Gy) in 3 fractions (range, 1-5) prescribed to the 75% isodose line. RESULTS: The median follow-up duration was 18.2 months. The 1-year local control was 76.4%, and patients treated with single vertebral body were identified as a favorable prognostic factor on multivariate analyses. Progression-free survival at 1 year was 31.9%, with the interval between initial diagnosis and SBRT and extent of disease at the time of treatment being significant prognostic factors. The 1-year overall survival was 80.5%, and PTV and visceral metastases were independently associated with inferior overall survival. CONCLUSION: SBRT for spinal sarcoma is effective in achieving local control, particularly when treating a single vertebral level with a limited extent of disease involvement, resulting in an excellent control rate. The extent of disease at the time of SBRT is significantly correlated with survival outcomes and should be considered when treating spine sarcoma.

Thecal Sac Contouring as a Surrogate for the Cauda Equina and Intracanal Spinal Nerve Roots for Spine Stereotactic Body Radiation Therapy (SBRT): Contour Variability and Recommendations for Safe Practice.

PURPOSE: To present interobserver variability in thecal sac (TS) delineation based on contours generated by 8 radiation oncologists experienced in spine stereotactic body radiation therapy and to propose contouring recommendations to standardize practice. METHODS AND MATERIALS: In the setting of a larger contouring study that reported target volume delineation guidelines specific to sacral metastases, 8 academically based radiation oncologists with dedicated spine stereotactic body radiation therapy programs independently contoured the TS as a surrogate for the cauda equina and intracanal spinal nerve roots. Uniform treatment planning simulation computed tomography datasets fused with T1, T2, and T1 post gadolinium magnetic resonance imaging for each case were distributed to each radiation oncologist. All contours were analyzed and agreement was calculated using both Dice similarity coefficient and simultaneous truth and performance level estimation with kappa statistics. RESULTS: A fair level of simultaneous truth and performance level estimation agreement was observed between practitioners, with a mean kappa agreement of 0.38 (range, 0.210.55) and the mean Dice similarity coefficient (± standard deviation, with range) was 0.43 (0.36 ± 0.1 to -0.53 ±0.1). Recommendations for a reference TS contour, accounting for the variations in practice observed in this study, include contouring the TS to encompass all the intrathecal spinal nerve roots, and caudal to the termination of the TS, the bony canal can be contoured as a surrogate for the extra thecal nerves roots that run within it. CONCLUSIONS: This study shows that even among high-volume practitioners, there is a lack of uniformity when contouring the TS. Further modifications may be required once dosimetric data on nerve tolerance to ablative doses, and pattern of failure analyses of clinical data sets using these recommendations, become available. The contouring recommendations were designed as a guide to enable consistent and safe contouring across general practice.

International consensus recommendations for target volume delineation specific to sacral metastases and spinal stereotactic body radiation therapy (SBRT).

BACKGROUND AND PURPOSE: To interrogate inter-observer variability in gross tumour volume (GTV) and clinical target volume (CTV) delineation specific to the treatment of sacral metastases with spinal stereotactic body radiation therapy (SBRT) and develop CTV consensus contouring recommendations. MATERIALS AND METHODS: Nine specialists with spinal SBRT expertise representing 9 international centres independently contoured the GTV and CTV for 10 clinical cases of metastatic disease within the sacrum. Agreement between physicians was calculated with an expectation minimisation algorithm using simultaneous truth and performance level estimation (STAPLE) and with kappa statistics. Optimised confidence level consensus contours were obtained using a voxel-wise maximum likelihood approach and the STAPLE contours for GTV and CTV were based on an 80% confidence level. RESULTS: Mean GTV STAPLE agreement sensitivity and specificity was 0.70 (range, 0.54-0.87) and 1.00, respectively, and 0.55 (range, 0.44-0.64) and 1.00 for the CTV, respectively. Mean GTV and CTV kappa agreement was 0.73 (range, 0.59-0.83) and 0.59 (range, 0.41-0.70), respectively. Optimised confidence level consensus contours were identified by STAPLE analysis. Consensus recommendations for the CTV include treating the entire segment containing the disease in addition to the immediate adjacent bony anatomic segment at risk of microscopic extension. CONCLUSION: Consensus recommendations for CTV target delineation specific to sacral metastases treated with SBRT were established using expert contours. This is a critical first step to achieving standardisation of target delineation practice in the sacrum and will serve as a baseline for meaningful pattern of failure analyses going forward.

A Nationwide Study of Surgery in a Newly Diagnosed Spine Metastasis Population.

OBJECTIVE: The aim of this nationwide study was to analyze the current state of patients with newly diagnosed metastatic spine tumors according to surgical methods. METHODS: Data was extracted from the Korean Health Insurance Review and Assessment Service database. Surgery was categorized into three. METHODS: fusion, decompression, and vertebroplasty. Data included patient age, sex, health insurance type, and co-morbidities. Survival rates of metastatic spine tumor patients according to each surgical method were evaluated. RESULTS: Among 1677 patients who had an operation, 823 patients were treated by fusion, 141 patients underwent decompression, and 713 patients were treated by vertebroplasty. The three most prevalent primary tumor sites were the lung, breast, and liver & biliary. On the other hand, the three most prevalent primary tumor sites of patients who underwent surgery were the lung, liver & biliary, and the prostate. The median survival periods for each surgical method in the metastatic spine tumor patients were 228 days for those who underwent surgery, 249 days for decompression, and 154 days for vertebroplasty. Age, sex, and comorbidities significantly affected survival rate. CONCLUSION: For every primary tumor site, decompression was the least common surgical method during the study period. Although the three surgical methods did not significantly affect the survival period, patients with a poor prognosis tended to undergo vertebroplasty.

Nationwide comparative study of synchronous and metachronous spine metastasis in the adult Korean population.

This nationwide study of the adult Korean population aimed to compare the survival period between synchronous and metachronous group and to determine recent treatment trends in newly diagnosed spine metastasis patients. Data were extracted from the Korean Health Insurance Review and Assessment Service database. Patients in this study were newly diagnosed with metastatic spine tumors between July 1, 2011 and June 31, 2014. The metachronous group was defined when the primary tumor was diagnosed prior to the diagnosis of spine metastasis, otherwise patients were considered to be the part of the synchronous group. The survival period was calculated from the date of first diagnosis of spine metastasis. In a multivariate analysis, patients in the synchronous group survived significantly longer than those in the metachronous group (P < 0.0001). Median overall survival periods were 273.6 days for the metachronous group and 541.4 days for the synchronous group. Conventional radiation therapy (RT) was the most common treatment modality for metastatic spine tumors, whereas surgery combined with RT was a steadily increasing treatment modality during the study period. Synchronous spine metastasis patients survive significantly longer than metachronous patients. Surgery combined with RT is a recently increasing trend among spine metastasis treatments.

A Nationwide Study of Stereotactic Radiosurgery in a Newly Diagnosed Spine Metastasis Population.

BACKGROUND: Stereotactic radiosurgery (SRS), a technique that is emerging as a new treatment option, has been reported to be an effective, noninvasive treatment for spine metastasis patients. OBJECTIVE: This nationwide study aimed to understand the current state of SRS for spine metastasis. METHODS: Patients in this study were first diagnosed with a metastatic spine tumor between 1 July and 31 December 2011. One group (the SRS group) received SRS at least once within 1 year of diagnosis and the other (the non-SRS group) did not receive SRS. We analyzed the characteristics, medication, and survival of each group. RESULTS: In 628 new patients, there were no significant differences between groups regarding gender, age, type of health insurance, and comorbidities. There were significant differences with regard to the medical costs (USD 23,276 vs. 18,458; p = 0.001) and the duration of hospital stay (101.3 vs. 86.5 days; p = 0.023). Median survival was significantly longer in the SRS group (p = 0.003). CONCLUSIONS: There was no significant pretreatment baseline demographic difference between the SRS and the non-SRS group. There was a tendency for greater use of medication in the SRS group. Patients with a longer overall survival tended to be those who underwent SRS treatment.

Consensus guidelines for postoperative stereotactic body radiation therapy for spinal metastases: results of an international survey.

OBJECTIVE Although postoperative stereotactic body radiation therapy (SBRT) for spinal metastases is increasingly performed, few guidelines exist for this application. The purpose of this study is to develop consensus guidelines to promote safe and effective treatment for patients with spinal metastases. METHODS Fifteen radiation oncologists and 5 neurosurgeons, representing 19 centers in 4 countries and having a collective experience of more than 1300 postoperative spine SBRT cases, completed a 19-question survey about postoperative spine SBRT practice. Responses were defined as follows: 1) consensus: selected by ≥ 75% of respondents; 2) predominant: selected by 50% of respondents or more; and 3) controversial: no single response selected by a majority of respondents. RESULTS Consensus treatment indications included: radioresistant primary, 1-2 levels of adjacent disease, and previous radiation therapy. Contraindications included: involvement of more than 3 contiguous vertebral bodies, ASIA Grade A status (complete spinal cord injury without preservation of motor or sensory function), and postoperative Bilsky Grade 3 residual (cord compression without any CSF around the cord). For treatment planning, co-registration of the preoperative MRI and postoperative T1-weighted MRI (with or without gadolinium) and delineation of the cord on the T2-weighted MRI (and/or CT myelogram in cases of significant hardware artifact) were predominant. Consensus GTV (gross tumor volume) was the postoperative residual tumor based on MRI. Predominant CTV (clinical tumor volume) practice was to include the postoperative bed defined as the entire extent of preoperative tumor, the relevant anatomical compartment and any residual disease. Consensus was achieved with respect to not including the surgical hardware and incision in the CTV. PTV (planning tumor volume) expansion was controversial, ranging from 0 to 2 mm. The spinal cord avoidance structure was predominantly the true cord. Circumferential treatment of the epidural space and margin for paraspinal extension was controversial. Prescription doses and spinal cord tolerances based on clinical scenario, neurological compromise, and prior overlapping treatments were controversial, but reasonable ranges are presented. Fifty percent of those surveyed practiced an integrated boost to areas of residual tumor and density override for hardware within the beam path. Acceptable PTV coverage was controversial, but consensus was achieved with respect to compromising coverage to meet cord constraint and fractionation to improve coverage while meeting cord constraint. CONCLUSIONS The consensus by spinal radiosurgery experts suggests that postoperative SBRT is indicated for radioresistant primary lesions, disease confined to 1-2 vertebral levels, and/or prior overlapping radiotherapy. The GTV is the postoperative residual tumor, and the CTV is the postoperative bed defined as the entire extent of preoperative tumor and anatomical compartment plus residual disease. Hardware and scar do not need to be included in CTV. While predominant agreement was reached about treatment planning and definition of organs at risk, future investigation will be critical in better understanding areas of controversy, including whether circumferential treatment of the epidural space is necessary, management of paraspinal extension, and the optimal dose fractionation schedules.

The Effect of Perioperative Radiation Therapy on Spinal Bone Fusion Following Spine Tumor Surgery.

INTRODUCTION: Perioperative irradiation is often combined with spine tumor surgery. Radiation is known to be detrimental to healing process of bone fusion. We tried to investigate bone fusion rate in spine tumor surgery cases with perioperative radiation therapy (RT) and to analyze significant factors affecting successful bone fusion. METHODS: Study cohort was 33 patients who underwent spinal tumor resection and bone graft surgery combined with perioperative RT. Their medical records and radiological data were analyzed retrospectively. The analyzed factors were surgical approach, location of bone graft (anterior vs. posterior), kind of graft (autologous graft vs. allograft), timing of RT (preoperative vs. postoperative), interval of RT from operation in cases of postoperative RT (within 1 month vs. after 1 month) radiation dose (above 38 Gy vs. below 38 Gy) and type of radiation therapy (conventional RT vs. stereotactic radiosurgery). The bone fusion was determined on computed tomography images. RESULT: Bone fusion was identified in 19 cases (57%). The only significant factors to affect bony fusion was the kind of graft (75% in autograft vs. 41 in allograft, p=0.049). Other factors proved to be insignificant relating to postoperative bone fusion. Regarding time interval of RT and operation in cases of postoperative RT, the time interval was not significant (p=0.101). CONCLUSION: Spinal fusion surgery which was combined with perioperative RT showed relatively low bone fusion rate (57%). For successful bone fusion, the selection of bone graft was the most important.

Establishment and characterization of a chordoma cell line from the tissue of a patient with dedifferentiated-type chordoma.

OBJECTIVE Chordoma is a rare bone tumor of the axial skeleton believed to originate from the remnants of the embryonic notochord. The available tumor cells are characteristically physaliferous and express brachyury, a transcription factor critical for mesoderm specification. Although chordomas are histologically not malignant, treatments remain challenging because they are resistant to radiation therapy and because wide resection is impossible in most cases. Therefore, a better understanding of the biology of chordomas using established cell lines may lead to the advancement of effective treatment strategies. The authors undertook a study to obtain this insight. METHODS Chordoma cells were isolated from the tissue of a patient with dedifferentiated-type chordoma (DTC) that had recurred. Cells were cultured with DMEM/F12 containing 10% fetal bovine serum and antibiotics (penicillin and streptomycin). Cell proliferation rate was measured by MTS assay. Cell-cycle distribution and cell surface expression of proteins were analyzed by fluorescence-activated cell sorting (FACS) analysis. Expression of proteins was analyzed by Western blot and immunocytochemistry. Radiation resistance was measured by clonogenic survival assay. Tumor formation was examined by injection of chordoma cells at hindlimb of nude mice. RESULTS The putative (DTC) cells were polygonal and did not have the conventional physaliferous characteristic seen in the U-CH1 cell line. The DTC cells exhibited similar growth rate and cell-cycle distribution, but they exhibited higher clonogenic activity in soft agar than U-CH1 cells. The DTC cells expressed high levels of platelet-derived growth factor receptor-ß and a low level of brachyury and cytokeratins; they showed higher expression of stemness-related and epithelial to mesenchymal transition-related proteins than the U-CH1 cells. Intriguingly, FACS analysis revealed that DTC cells exhibited marginal surface expression of CD24 and CD44 and high surface expression of CXCR4 in comparison to U-CH1 cells. In addition, blockade of CXCR4 with its antagonist AMD3100 effectively suppressed the growth of both cell lines. The DTC cells were more resistant to paclitaxel, cisplatin, etoposide, and ionizing radiation than the U-CH1 cells. Injection of DTC cells into the hindlimb region of nude mice resulted in the efficient formation of tumors, and the histology of xenograft tumors was very similar to that of the original patient tumor. CONCLUSIONS The use of the established DTC cells along with preestablished cell lines of chordoma may help bring about greater understanding of the mechanisms underlying the chordoma that will lead to therapeutic strategies targeting chordomas.

A nationwide epidemiological study of newly diagnosed spine metastasis in the adult Korean population.

BACKGROUND CONTEXT: Metastatic spine tumor has become clinically important because of the availability of improved diagnostic tools and increases in survival periods in cancer patients. In spite of this interest, the burden of metastatic spine tumor on the general population has not been extensively reported. PURPOSE: The aim of this 2009-2011 nationwide study of adult Koreans was to describe characteristics, medical use, and survival rate of patients with newly diagnosed metastatic spine tumors according to the primary tumor. DESIGN/SETTING: This is a retrospective cohort study. PATIENT SAMPLE: A national health insurance database was used to identify a cohort of patients with newly diagnosed metastatic spine tumors. OUTCOME MEASURES: This study aimed to analyze characteristics, medical use, and survival rate of patients with newly diagnosed metastatic spine tumors according to the primary tumor. METHODS: Data for patients with metastatic spine tumors were extracted from the Korean Health Insurance Review and Assessment Service database. Data included patient age, sex, health insurance type, comorbidities, medical cost, and hospital stay duration. Hospital stay duration and medical costs per person during 1 calendar year were evaluated. In addition, survival rates of patients with metastatic spine tumor according to primary tumor sites were evaluated. RESULTS: The incidence rate of spine metastasis increased with age, year of diagnosis, and the number of comorbidities (p≤.0001). The 6 most prevalent primary tumor sites were lung, liver and biliary tract, breast, colon, stomach, and prostate. Of patients with the 6 most prevalent primary tumors, total average annual medical costs, including inpatient and outpatient services, ranged from 12,734USD (prostate origin) to 15,556 USD (lung origin). Of patients with the 6 most prevalent primary tumors, total average annual hospital stay duration, including inpatient and outpatient services, ranged from 70.8 days (stomach origin) to 78.7 days (colon origin). Median overall survival duration in patients with metastatic spine tumor was 191 days. In addition to age, sex, and comorbidities, primary tumor sites (lung, liver and biliary tract, breast, stomach, and prostate) significantly affected survival rate. CONCLUSIONS: This nationwide study was able to depict the burden of metastatic spine tumor in Korea. The metastatic spine tumor incidence rate is highest in the group of 70- to 79-year-old men. Average annual medical costs ranged from 12,734 USD to 15,556 USD. The mean annual hospital stay duration was from 70.8 days to 78.7 days. In addition to age, sex, and comorbidities, primary tumor sites significantly affected the survival rate in patients with metastatic spine tumor.

Clinical Outcome of Treatment for Patients with Giant Cell Tumor in Spine.

OBJECTIVE: The treatment of giant cell tumor (GCT) is mainly performed surgically. However, GCT in spine seems difficult to treat because of the limited surgical accessibility and proximity. In this report, we analyzed the outcome of GCT treatment in spine. METHODS: Between 2000 and 2012, 19 patients received treatment for GCT in spine. Median age at their first diagnosis was 31 years, 10 patients were male, and 9 female. Fourteen tumors were located in the sacrum, 1 in cervical, 1 in thoracic and 3 in lumbar spine. As primary treatment, gross total removal (GTR) was done in 6 patients, and subtotal removal (STR) in 13 patients. Radiation therapy (RT) as an adjuvant therapy was performed in 2 cases in GTR group and 10 cases in STR group. RESULTS: During the follow-up, 7 patients had local recurrence (36.8%). The average period until recurrence after primary treatment was 14 months. No recurrence was detected in GTR group. Recurrence was noted in 7 out of 13 patients who underwent STR. These differences were statistically significant (p=0.024). A median of recurrence free period (RFP) was 84 months. Also average RFP of the RT group was 112 months, and non-RT group was 65 months. These differences were statistically significant (p=0.041). CONCLUSION: Treatment of choice for GCT in spine is a complete removal of tumor without neurological deficits. In case of incomplete removal, radiation therapy may be a useful adjuvant treatment modality.

Two Cases of Dedifferentiated Chordoma in the Sacrum.

Dedifferentiated chordoma (DC) is defined as a chordoma containing sarcoma components. DC is distinguished from conventional chordoma by the rapidity of tumor growth and the potential for distant metastasis. We report two cases of DC, which are developed in the sacrum. We reviewed the medical records and imaging studies of 2 patients diagnosed with DC and the literature published. In the first case, percutaneous biopsy revealed that it was conventional chordoma in the sacrum. Patient underwent radiation therapy (RT). Six years after the RT, the tumor recurred. Surgical removal was performed and the recurrent tumor was diagnosed as DC in histopathologic examination. In the second case, a patient underwent gross total resection of sacral tumor, which was diagnosed with conventional chordoma. Aggravated tumor was detected after 4 months, and patient underwent reoperation. The second operation revealed the transformation of the tumor into DC. The survival time of the patients after the diagnosis was 10 and 31 months. Dedifferentiated chordoma is a rare and highly aggressive tumor. De novo type exists, but it usually transformed from recurrent chordoma after surgical resection or radiation.

Which one is a valuable surrogate for predicting survival between Tomita and Tokuhashi scores in patients with spinal metastases? A meta-analysis for diagnostic test accuracy and individual participant data analysis.

This study is to estimate the diagnostic accuracy of Tokuhashi and Tomita scores that assures 6-month predicting survival regarded as a standard of surgical treatment. We searched PubMed, EMBASE, European PubMed central, and the Cochrane library for papers about the sensitivities and specificities of the Tokuhashi and/or Tomita scores to estimate predicting survival. Studies with cut-off values of ≥9 for Tokuhashi and ≤7 for Tomita scores based on prior studies were enrolled. Sensitivity, specificity, diagnostic odds ratio (DOR), area under the curve (AUC), and the best cut-off value were calculated via meta-analysis and individual participant data analysis. Finally, 22 studies were enrolled in the meta-analysis, and 1095 patients from 8 studies were included in the individual data analysis. In the meta-analysis, the pooled sensitivity/specificity/DOR for 6-month survival were 57.7 %/76.6 %/4.70 for the Tokuhashi score and 81.8 %/47.8 %/4.93 for Tomita score. The AUC of summary receiver operating characteristic plots was 0.748 for the Tokuhashi score and 0.714 for the Tomita score. Although Tokuhashi score was more accurate than Tomita score slightly, both showed low accuracy to predict 6 months residual survival. Moreover, the best cut-off values of Tokuhashi and Tomita scores were 8 and 6, not 9 and 7, for predicting 6-month survival, respectively. Estimation of 6-month predicting survival to decide surgery in patients with spinal metastasis is quite limited by using Tokuhashi and Tomita scores alone. Tokuhashi and Tomita scores could be incorporated as part of a multidisciplinary approach or perhaps interpreted in the context of a multidisciplinary approach.

Nationwide epidemiology and healthcare utilization of spine tumor patients in the adult Korean population, 2009-2012.

BACKGROUND: The aim of this nationwide study was to describe the incidence and health care utilization of adult Korean patients with primary malignant, primary nonmalignant, and metastatic spine tumors between 2009 and 2012. METHODS: Patients with primary and metastatic spine tumors were identified from the Korean Health Insurance Review and Assessment Service database between January 1, 2009, and December 31, 2012. Demographics, incidence rate, annual medical cost, and annual hospital stay of each new patient were reviewed. RESULTS: Of 1600 primary spine tumors diagnosed from 2009 to 2012, 373 (23.3%) were malignant, and 1227 (76.7%) were nonmalignant. The most common tumor type was neoplasm of spinal cord among primary malignant (C72.0, 51.5%) and primary nonmalignant (D33.4, 66.2%) spine tumors. Differences in primary malignant, primary nonmalignant, and metastatic spine tumor incidence by sex were significant (P = .004, <.001, and <.001, respectively). The annual incidence rate of primary nonmalignant and metastatic spine tumors increased significantly over the study period (P = .005 and <.001, respectively). Lung, liver/biliary, and breast were the most prevalent original tumor sites for metastatic spine tumors. In 2011, average annual medical costs associated with treatment of primary malignant, primary nonmalignant, and metastatic tumors were US $15 223, $6502, and $16 038, respectively. Average annual hospital stay durations for primary malignant, primary nonmalignant, and metastatic spine tumors in 2011 were 103.4, 61.7, and 79.6 days, respectively. CONCLUSIONS: This is the first nationwide analysis of spine tumors, including metastatic spine tumors, in Asia.

Clinical significance of radiological stability in reconstructed thoracic and lumbar spine following vertebral body resection.

OBJECTIVE: Vertebral body replacement following corpectomy in thoracic or lumbar spine is performed with titanium mesh cage (TMC) containing any grafts. Radiological changes often occur on follow-up. This study investigated the relationship between the radiological stability and clinical symptoms. METHODS: The subjects of this study were 28 patients who underwent corpectomy on the thoracic or lumbar spine. Their medical records and radiological data were retrospectively analyzed. There were 23 cases of tumor, 2 cases of trauma, and 3 cases of infection. During operation, spinal reconstruction was done with TMC and additional screw fixation. We measured TMC settlement in sagittal plane and spinal angular change in coronal and sagittal plane at postoperative one month and last follow-up. Pain score was also checked. We investigated the correlation between radiologic change and pain status. Whether factors, such as the kind of graft material, surgical approach, and fusion can affect the radiological stability or not was analyzed as well. RESULTS: Mean follow-up was 23.6 months. During follow-up, 2.08±1.65° and 6.96±2.08° of angular change was observed in coronal and sagittal plane, respectively. A mean of cage settlement was 4.02±2.83 mm. Pain aggravation was observed in 4 cases. However, no significant relationship was found between spinal angular change and pain status (p=0.518, 0.458). Cage settlement was seen not to be related with pain status, either (p=0.644). No factors were found to affect the radiological stability. CONCLUSION: TMC settlement and spinal angular change were often observed in reconstructed spine. However, these changes did not always cause postoperative axial pain.

Evaluation of risk factors for vertebral compression fracture after stereotactic radiosurgery in spinal tumor patients.

OBJECTIVE: Stereotactic radiosurgery (SRS) is an emerging treatment modality for malignant spinal tumors. After SRS, some patients suffered from pain aggravation due to development of vertebral compression fracture (VCF). In these cases, surgery should be considered. METHODS: This study consisted of 72 patients who underwent SRS due to spinal tumors. In them, whether post-SRS VCF developed or not was investigated. We retrospectively analyzed their medical records and radiological imaging data. VCF was diagnosed with X-ray and magnetic resonance imaging (MRI). The incidence, time to development and risk factors for VCF were investigated. Age, sex, whole vertebral body involvement rate, vertebral body osteolysis rate, pre-SRS spinal deformity, spinal instability neoplastic score (SINS), spinal canal encroachment, lesion level, and radiation dose were analyzed as potential risk factors. A multi-variate logistic regression model was used for statistical analysis. RESULTS: In our study population, VCF was observed in 26 patients (36%). The mean time to VCF development was 1.5 months. Using uni-variate analyses, the significant risk factors were pre-SRS spinal deformity, SINS, vertebral body osteolysis rate, and whole vertebral body involvement rate. However, using multi-variate analyses, the only significant risk factor was vertebral body osteolysis rate. The patients whose vertebral body was destroyed by more than 60% showed an 8.4 times higher risk of VCF than those who had vertebral body destruction of less than 60%(p=0.016). CONCLUSION: The most significant prognostic factor for post-SRS VCF was vertebral body osteolysis rate, rather than whole vertebral body involvement rate. When more than 60% of the vertebral body was destroyed, the risk of VCF or spinal deformity was high.

Clinical result of stereotactic radiosurgery for spinal metastasis from hepatocellular carcinoma: comparison with conventional radiation therapy.

We investigated the clinical outcome following stereotactic radiosurgery (SRS) for spinal metastasis from hepatocellular carcinoma (HCC) and compared it with that of conventional radiation therapy (cRT). Thirty-nine metastatic spine tumors from 27 HCC patients were treated with SRS from 2002 to 2011. Their medical records and radiological data were retrospectively analyzed. Median tumor volume was 49.7 cc, and a mean marginal dose of 28.7 Gy was delivered to the tumor mass. We analyzed overall survival (OS), local progression-free survival, and the rate of pain control following SRS. Factors relating to clinical outcomes were also investigated. Clinical results following cRT were obtained from 32 patients. The cRT protocol consisted of 30 Gy in 10 fractions or 39 Gy in 13 fractions. OS and local progression-free survival were compared between SRS and cRT. OS was a median of 7 months following SRS. Significant prognostic factors relating to OS included Child-Pugh class and Karnofsky performance scale. Tumor recurrence was noted in nine lesions during follow-up. The median local progression-free survival was 7 months. Previous irradiation was a significant prognostic factor for local recurrence (P = 0.043). The overall pain control rate was 85 % and no factors were found to be significantly correlated with the pain control rate. The median OS was 3 months in the cRT group and 7 months in the SRS group (P = 0.035). The median local progression-free survival was 2.0 months in the cRT group, and 7.0 months in the SRS group, which were significantly different (P = 0.033). SRS showed better local control than cRT in the treatment of HCC spinal metastasis.

Stereotactic radiosurgery compared with external radiation therapy as a primary treatment in spine metastasis from renal cell carcinoma: a multicenter, matched-pair study.

The aim of this multicenter, matched- pair study was to compare the outcome of stereotactic radiosurgery (SRS) with that of external radiation therapy (RT) when used as a primary treatment in spine metastasis from renal cell carcinoma (RCC). From 2005 to 2012, 13 patients underwent SRS as a primary treatment in spine metastasis from RCC. Thirteen patients who underwent RT as the primary treatment of RCC spine metastasis were paired with the SRS patients based on age, number of spine metastasis, time interval from original tumor diagnosis to spine metastasis, Eastern Cooperative Oncology Group status, and year of treatment. The primary outcomes of interest were pain relief and progression free survival. Secondary outcomes were treatment toxicities and need for further treatment. The perioperative VAS score decrease was larger in the SRS group than that in the RT group (P = 0.04). More SRS patients had complete or partial pain relief although the difference was not significant. There was a significant difference in progression free survival between the two groups (P = 0.01). The percentage of patients with toxicities was 38.5 % (5/13) in the SRS group and 53.9 % (7/13) in the RT group, but the difference was not significant. There were 2 SRS patients and 3 RT patients who received further intervention at the index segment. This study showed that, when performed as a primary treatment in spine metastasis from RCC, SRS provides relatively better pain relief and better local control than that obtained from RT.

Stereotactic radiosurgery for primary malignant spinal tumors.

OBJECTIVES: We adopted stereotactic radiosurgery (SRS) to treat primary malignant spinal tumors. The objective of this study was to evaluate local control rate and to identify prognostic factors after SRS for primary malignant spinal tumors. METHODS: Medical records and radiological data for 29 patients with primary malignant spinal tumors were retrospectively analyzed. The histological diagnoses were chordoma (11 cases), chondrosarcoma (5 cases), osteosarcoma (3 cases), synovial sarcoma (3 cases), plasmacytoma (2 cases), Ewing sarcoma (2 cases), malignant peripheral nerve sheath tumor (2 cases), and malignant fibrous histiocytoma (1 case). Patient age ranged from 11 to 68 years (median, 46 years). Surgical resection and percutaneous biopsy were chosen as initial treatments in 25 and 4 cases, respectively. Stereotactic radiosurgery was used as primary treatment method in 14 cases and as a salvage treatment for progressed lesions in 15 cases. Distant metastasis was noted in two sarcoma patients. Eleven patients had undergone previous conventional external beam radiation therapy (cEBRT) before SRS. Overall survival, local progression-free survival, and the prognostic factors affecting local recurrence were investigated. RESULTS: Tumor volume ranged from 2·0 to 235 cc (median, 14 cc). Delivered radiation doses were from 12 to 50 Gy with two to six sessions. The mean radiation dose converted into a biological effective dose (BED) was 60 Gy (range, 43-105 Gy). The mean follow-up period was 50 months (range, 8-126 months). The mean overall survival was 84 months for chordoma patients and 104 months for sarcoma patients. No factors that affected overall survival were found. The mean local progression-free survival was 56 months for chordoma patients and 73 months for sarcoma patients. The recurrent mode of presentation was predictive of local progression of spinal sarcomas (P  =  0·009). However, in chordoma patients, no factors were found to correlate with local recurrence. CONCLUSION: These preliminary results suggest that SRS could provide good local control when applied as postoperative adjuvant or salvage treatment after cEBRT for primary malignant spinal tumors.