• Radiation Oncology Journal
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• v.33 no.1
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• pp.1-11
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• 2015

With the progress of image-guided localization, body immobilization system, and computerized delivery of intensity-modulated radiation delivery, it became possible to perform spine radiosurgery. The next question is how to translate the high technology treatment to the clinical application. Clinical trials have been performed to demonstrate the feasibility of spine radiosurgery and efficacy of the treatment in the setting of spine metastasis, leading to the randomized trials by a cooperative group. Radiosurgery has also demonstrated its efficacy to decompress the spinal cord compression in selected group of patients. The experience indicates that spine radiosurgery has a potential to change the clinical practice in the management of spine metastasis and spinal cord compression.

• Journal of Korean Neurosurgical Society
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• v.51 no.1
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• pp.1-7
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• 2012

Objective : The incidence and prevalence of spinal metastases are increasing, and although the role of radiation therapy in the treatment of metastatic tumors of the spine has been well established, the same cannot be said about the role of stereotactic radiosurgery. Herein, the authors present a systematic review regarding the value of spinal stereotactic radiosurgery in the management of spinal metastasis. Methods : A systematic literature search for stereotactic radiosurgery of spinal metastases was undertaken. Grades of Recommendation, Assessment, Development, and Education (GRADE) working group criteria was used to evaluate the qualities of study datasets. Results : Thirty-one studies met the study inclusion criteria. Twenty-three studies were of low quality, and 8 were of very low quality according to the GRADE criteria. Stereotactic radiosurgery was reported to be highly effective in reducing pain, regardless of prior treatment. The overall local control rate was approximately 90%. Additional asymptomatic lesions may be treated by stereotactic radiosurgery to avoid further irradiation of neural elements and further bone-marrow suppression. Stereotactic radiosurgery may be preferred in previously irradiated patients when considering the radiation tolerance of the spinal cord. Furthermore, residual tumors after surgery can be safely treated by stereotactic radiosurgery, which decreases the likelihood of repeat surgery and accompanying surgical morbidities. Encompassing one vertebral body above and below the involved vertebrae is unnecessary. Complications associated with stereotactic radiosurgery are generally self-limited and mild. Conclusion : In the management of spinal metastasis, stereotactic radiosurgery appears to provide high rates of tumor control, regardless of histologic diagnosis, and can be used in previously irradiated patients. However, the quality of literature available on the subject is not sufficient.

• Progress in Medical Physics
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• v.24 no.3
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• pp.145-153
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• 2013

Stereotactic body radiation therapy (SBRT) is increasingly used to treat spinal metastases. To achieve the highest steep dose gradients and conformal dose distributions of target tumors, intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques are essential to spine radiosurgery. The purpose of the study was to qualitatively compare IMRT and VMAT techniques with International Spine Radiosurgery Consortium (ISRC) contoured consensus guidelines for target volume definition. Planning target volume (PTV) was categorized as TB, $T_{BPT}$ and $T_{ST}$ depending on sectors involved; $T_B$ (vertebral body only), $T_{BPT}$ (vertebral body+pedicle+transverse process), and $T_{ST}$ (spinous process+transverse process). Three patients treated for spinal tumor in the cervical, thoracic, and lumbar region were selected. Eacg tumor was contoured by the definition from the ISRC guideline. Maximum spinal cord dose were 12.46 Gy, 12.17 Gy and 11.36 Gy for $T_B$, $T_{BPT}$ and $T_{ST}$ sites, and 11.81 Gy, 12.19 Gy and 11.99 Gy for the IMRT, RA1 and RA2 techniques, respectively. Average fall-off dose distance from 90% to 50% isodose line for $T_B$, $T_{BPT}$, and $T_{ST}$ sites were 3.5 mm, 3.3 mm and 3.9 mm and 3.7 mm, 3.7 mm and 3.3 mm for the IMRT, RA1 and RA2 techniques, respectively. For the most complicated target $T_{BPT}$ sites in the cervical, thoracic and lumbar regions, the conformity index of the IMRT, RA1 and RA2 is 0.621, 0.761 and 0.817 and 0.755, 0.796 and 0.824 for rDHI. Both IMRT and VMAT techniques delivered high conformal dose distributions in spine stereotactic radiosurgery. However, if the target volume includes the vertebral body, pedicle, and transverse process, IMRT planning resulted in insufficient conformity index, compared to VMAT planning. Nevertheless, IMRT technique was more effective in reducing the maximum spinal cord dose compared to RA1 and RA2 techniques at most sites.

• Progress in Medical Physics
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• v.32 no.2
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• pp.40-49
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• 2021

Purpose: This study aimed to develop a surface-guided radiosurgery system customized for a neurosurgery clinic that could be used as an auxiliary system for improving the accuracy, monitoring the movements of patients while performing hypofractionated radiosurgery, and minimizing the geometric misses. Methods: RGB-D cameras were installed in the treatment room and a monitoring system was constructed to perform a three-dimensional (3D) scan of the body surface of the patient and to express it as a point cloud. This could be used to confirm the exact position of the body of the patient and monitor their movements during radiosurgery. The image from the system was matched with the computed tomography (CT) image, and the positional accuracy was compared and analyzed in relation to the existing system to evaluate the accuracy of the setup. Results: The user interface was configured to register the patient and display the setup image to position the setup location by matching the 3D points on the body of the patient with the CT image. The error rate for the position difference was within 1-mm distance (min, -0.21 mm; max, 0.63 mm). Compared with the existing system, the differences were found to be as follows: x=0.08 mm, y=0.13 mm, and z=0.26 mm. Conclusions: We developed a surface-guided repositioning and monitoring system that can be customized and applied in a radiation surgery environment with an existing linear accelerator. It was confirmed that this system could be easily applied for accurate patient repositioning and inter-treatment motion monitoring.

• 대한방사선방어학회:학술대회논문집
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• 2011.04a
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• pp.128-129
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• 2011

• Journal of Korean Neurosurgical Society
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• v.59 no.1
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• pp.37-43
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• 2016

Objective : The aim of this multicenter, matched-pair study was to compare the outcomes of stereotactic radiosurgery (SRS) and conventional external radiation therapy (RT) when used as a primary treatment in spine metastasis from hepatocellular carcinoma (HCC). Methods : From 2005 to 2012, 28 patients underwent SRS as the primary treatment in spine metastasis from HCC. Based on sex, age, number of spine metastasis, Child-Pugh classification, interval from original tumor to spine metastasis, and year of treatment, 28 patients who underwent RT were paired. Outcomes of interest were pain relief, progression free survival, toxicities, and further treatment. Results : The perioperative visual analog scale (VAS) decrease was larger in SRS group than in RT group, but the difference was not significant (3.7 vs. 2.8, p=0.13). When pain medication was adjusted, the number of patients with complete (n=6 vs.3) or partial (n=12 vs.13) relief was larger in SRS group than in RT group; however, the difference was not significant (p=0.83). There was no significant difference in progression free survival (p=0.48). In SRS group, 32.1% of patients had 1 or more toxicities whereas the percentage in RT group was 63.0%, a significant difference (p=0.04). Six SRS patients and 7 RT patients received further intervention at the treated segment. Conclusion : Clinical and radiological outcome were not significantly different between the two treatments. Toxicities, however, were more prevalent in the RT group.

• Radiation Oncology Journal
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• v.31 no.4
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• pp.260-266
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• 2013

A clear consensus has not been established regarding the best treatment for solitary bone metastasis. Here, we reviewed the medical records of patients with a controlled primary malignancy who had only solitary spine metastasis without metastasis to the extraspinal bone or viscera and underwent treatment between April 2007 and December 2012 with stereotactic body radiosurgery using CyberKnife, with a total dose of 24 Gy in three to four fractions. During that time, there were only four cases. This was effective in each case, and all the four patients had no local failure and remained alive at a median follow-up of 68 months (range, 64 to 80 months). Although our experience is limited, this study suggests that stereotactic body radiotherapy could be a feasible, safe, effective, and noninvasive alternative treatment for solitary spine metastasis in patients who are medically inoperable or unsuitable for surgery.

• Journal of Korean Neurosurgical Society
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• v.54 no.3
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• pp.246-249
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• 2013

A solitary fibrous tumor (SFT) is a rare neoplasm originated from the pleura, but they can occur in a variety of extrathoracic regions. Although many cases of primary SFT have been reported, there are extremely rare repots to date of a malignant SFT in the spine or skull. A 54-year-woman visited our hospital due to low back pain and both leg radiating pain. Several imaging studies including magnetic resonance imaging and computed tomography revealed expansive enhanced lesions in the occipital bone, T8, S1-2, and ilium, with neural tissue compression. We performed surgical resection of the tumor in each site, and postoperative radiosurgery and chemotherapy were performed. However, after six months, tumors were recurred and metastasized in multiple regions including whole spine and lung. The authors report here the first case of patient with malignant SFT of tandem lesions in the various bony structures, including skull, thoracic spine, and sacral spine, with a rapid recurrence and metastasis. Although malignant SFT is extremely rare, it should be considered in the differential diagnosis and carful follow-up is needed.

• Progress in Medical Physics
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• v.22 no.1
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• pp.12-17
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• 2011

This study has its own goal to deliver the accurate dose on the target volume by calculating and modifying the attenuation rate of photon beam transmitting the couch top with geometric model. The experiment was that the transmission rate and attenuation rate of photon beam transmitting the couch top was predicted by the geometric model, then compared and analyzed with what was measured experimentally based on that. The result showed that the predicted value by the geometric model accorded closely with the experimental value. In addition, in order to judge whether the practical clinical application is available, the point dose, measured after modifying the attenuation rate modelinged according to the treatment plan of a patient of spine radiosurgery, was compared with the one done nothing. The result was that the former showed decreased error range with treatment planned one than the latter. This papers calculated the transmission and attenuation rate with the geometric model transmitting the couch top and verified it experimentally. This method is expected to be very useful in not only the radiosurgery using Novalis but also the general radiation therapy.

• Journal of Korean Neurosurgical Society
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• v.38 no.3
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• pp.184-189
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• 2005

Objective : Hemangioblastomas are highly vascular and benign neoplasm of the central nervous system[CNS]. They can often be found as multiple lesions, as is commonly observed in von Hippel-Lindau[VHL] disease. The aim of this study is to determine the proper management for multiple hemangioblastomas. Methods : Since 1990, 78cases of hemangioblastoma have been encountered. Among these, 9cases were multiple hemangioblastomas that were treated with surgical resection with or without radiosurgery. The medical, radiological, surgical and histological records were reviewed retrospectively and analyzed statistically. Results : Nine patients presented with multiple hemangioblastomas and were diagnosed as VHL disease. The mean follow-up duration was 75.7months [$6.6{\sim}159.2months$] after the first surgical treatment. Three patients were treated with surgical resection alone and six patients were treated by both surgical resection and radiosurgery. Twenty-one surgical procedures [13 surgical resections and 8 radiosurgery] were performed. One patient required ventriculoperitoneal shunt and a posterior fossa decompressive craniectomy because of post-radiation brain swelling. Another patient refused additional treatment for the newly developed lesions after the successful treatment of initial lesions. The other patient who presented with numerous lesions in the whole brain and spine underwent cranio-spinal irradiation. Remaining patients showed good results. Conclusion : The surgical outcomes for the patients with a single lesion of the CNS hemangioblastoma are favorable. However. the treatment of multiple hemangioblastoma is more difficult, and should be treated by surgical resection and radiosurgery with careful consideration.