• Journal of Korean Neurosurgical Society
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• v.29 no.3
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• pp.336-344
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• 2000

Objective : The treatment for prolactin secreting pituitary adenoma(prolactinoma) include pharmacology, surgery, radiation therapy or radiosurgery. The recent development of radiological imaging and microsurgery has made transsphenoidal microsurgery the treatment of choice for most prolactin secreting pituitary adenoma. Despite its low morbidity and mortality, relatively high recurrence and failure rate have been reported. Recent advances in neuroimaging provide a precise targeting in radiosurgery for treatment of prolactin secreting pituitary adenoma. In this regard, Gamma knife radiosurgery has been proposed as an alternative primary treatment modality or adjuvant therapy. Patients and Methods : Twenty three patients with prolactin secreting pituitary adenoma have been treated with Gamma knife radiosurgery in our institute from March 1992 to September 1998. We analyzed clinical, radiological and endocrinological changes in 21 patients who were followed up for an average of 35.7 months. Results : The mean age was 34.9 years and 16 patients were treated with Gamma knife radiosurgery as primary treatment and 5 patients underwent Gamma knife radiosurgery for residual tumors after microsurgery. The margin of the tumor was incorporated within the 40 to 80% and the mean marginal dose was 24.5 Gy. Clinical improvement in the last follow-up were present in 17 cases(81.0%) and 3 of 5 infertility patients became pregnant after Gamma knife radiosurgery. Tumor control rate after Gamma knife radiosurgery was 100%. Endocrinological normalization in the last follow-up were obtained in 12 cases(57.1%). In three cases, hormonal normalizations were present in early period(3-32 months) but serum hormone levels were elevated subsequently. Conclusion : We conclude that the Gamma knife radiosurgery for prolactin secreting pituitary adenoma seems to be safe and effective as adjuvant therapy after microsurgery and primary treatment modality in selective patients.

• Journal of Radiation Industry
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• v.12 no.4
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• pp.337-341
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• 2018

Sector block is not used for Gamma Knife surgery in patients with generalized trigeminal neuralgia but sector block is used to reduce the dose reaching the brain stem when the trigeminal ganglgia and the 'Brain stem', radiation sensitive tissue, are adjacent. In the Gamma Knife surgical plan of this study, a surgical plan was established using a Leksell Gamma Plan 11. 1.0 (Elekta Instrument AB, Sweden) with one patient (Block unused, Brain stem dose No volume over 12 Gy, Case 1) who did not need a sector block and four patients (Block unused, Brain stem dose 12 Gy or more, Case 2~5) with a sector block. Magnetic resonance images were obtained by MPRAGE T1 and CISS Respectively. When the trigeminal ganglion is in close proximity to the brain stem, the brain stem volume is decreased when the sector block is used, while the treatment time was increased. In conclusion, This Study evaluates the usefulness of the Sector block in brain stem through Gamma Knife surgery in trigeminal neuralgia, which is considered to be the most important factor for the Gamma Knife surgery.

• Journal of Korean Neurosurgical Society
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• v.61 no.5
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• pp.633-639
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• 2018

Objective : We investigated the outcomes of repeat stereotactic radiosurgery (SRS) for metastatic brain tumors that locally recurred despite previous SRS, focusing on the tumor control. Methods : A total of 114 patients with 176 locally recurring metastatic brain tumors underwent repeat SRS after previous SRS. The mean age was 59.4 years (range, 33 to 85), and there were 68 male and 46 female patients. The primary cancer types were non-small cell lung cancer (n=67), small cell lung cancer (n=12), gastrointestinal tract cancer (n=15), breast cancer (n=10), and others (n=10). The number of patients with a single recurring metastasis was 95 (79.8%), and another 19 had multiple recurrences. At the time of the repeat SRS, the mean volume of the locally recurring tumors was 5.94 mL (range, 0.42 to 29.94). We prescribed a mean margin dose of 17.04 Gy (range, 12 to 24) to the isodose line at the tumor border primarily using a 50% isodose line. Results : After the repeat SRS, we obtained clinical and magnetic resonance imaging follow-up data for 84 patients (73.7%) with a total of 108 tumors. The tumor control rate was 53.5% (58 of the 108), and the median and mean progression-free survival (PFS) periods were 246 and 383 days, respectively. The prognostic factors that were significantly related to better tumor control were prescription radiation dose of 16 Gy (p=0.000) and tumor volume less than both 4 mL (p=0.001) and 10 mL at the repeat SRS (p=0.008). The overall survival (OS) periods for all 114 patients after repeat SRS varied from 1 to 56 months, and median and mean OS periods were 229 and 404 days after the repeat SRS, respectively. The main cause of death was systemic problems including pulmonary dysfunction (n=58, 51%), and the identified direct or suspected brain-related death rate was around 20%. Conclusion : The tumor control following repeat SRS for locally recurring metastatic brain tumors after a previous SRS is relatively lower than that for primary SRS. However, both low tumor volume and high prescription radiation dose were significantly related to the tumor control following repeat SRS for these tumors after previous SRS, which is a general understanding of primary SRS for metastatic brain tumors.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.901-907
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• 2019

The aim of this study is to evaluate the ability of target localizations of Leksell GammaPlan(LGP) in Gamma Knife Subthalamotomy(or Pallidotomy, Thalamotomy) of functional diseases. To evaluate the accuracy of LGP's location settings, the difference Δr of the target coordinates calculated by LGP (or LSP) and author's algorithm was reviewed for 10 patients who underwent Deep Brain Stimulation(DBS) surgery. Δr ranged from 0.0244663 mm to 0.107961 mm. The average of Δr was 0.054398 mm. Transformation matrix between stereotactic space and brain atlas space was calculated using PseudoInverse or Singular Value Decomposition of Mathematica to determine the positional relationship between two coordinate systems. Despite the precise frame positioning, the misalignment of yaw from -3.44739 degree to 1.82243 degree, pitch from -4.57212 degree to 0.692063 degree, and rolls from -6.38239 degree to 7.21426 degree appeared. In conclusion, a simple in-house algorithm was used to test the accuracy for location settings of LGP(or LSP) in Gamma Knife platform and the possibility for Gamma Knife Subthalamotomy. The functional diseases can be treated with Gamma Knife Radiosurgery with safety and efficacy. In the future, the proposed algorithm for target localizations' QA will be a great contributor to movement disorders' treatment of several Gamma Knife Centers.

• The Journal of the Korean bone and joint tumor society
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• v.11 no.1
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• pp.17-24
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• 2005

Local treatment for tumors has developed from extended radical surgery to function preserving surgery on the basis of modern biology. With the development of minimally invasive technique, it changed to be minimal-invasive surgery. And nowadays technical revolution made non-invasive surgery possible with appearance of several kinds of non-surgical knives such as gamma knife, cyber knife, and HIFU (high intensity focused ultrasound) knife. In this article, history, HIFU machine and treatment procedure, histological change and its mechanism, clinical applications, advantage, disadvantage, and future prospect of extracorporeal high intensity focused ultrasound therapy using HIFU knife will be reviewed.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1024-1029
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• 2000

Objectives : With recent improvements in neuroimaging and the development of third and fourth-generation radiosurgical dose-planning soft ware, came a renewed interest in using radiosurgery for the treatment of movement disorders. Radiosurgery involves no opening of the cranium and no incisions, eliminating both the risk of hemorrhage from passing an electrode to the depths of meningitis from operative infection. It is for these reasons stereotactic radiosurgical treatment of movement disorders has value in a small subgroup of patients. The authors report four cases of Parkinson's disease and one case of dystonia that were treated by Gamma knife. Methods : Radiosurgical nucleus ventralis intermedius thalamotomy using the gamma knife unit was performed to make lesion in two Parkinson's disease patients. A radiation dose of 120Gy was delivered to nucleus using a single 4-mm collimator plug pattern following classic anatomical landmarks. Patients were followed for a median of 10.5 months(range 9-12 months). An independent neurological evaluation of tremor, based on the change in the United Parkinson's Disease Rating Scale tremor score(UPDRS), was correlated with a subjective evaluation. Gamma knife ventrolateral(V.O.P) thalamotomy was performed in one case of dystonia. A central dose of 150Gy was delivered and the patient was followed for 18 months. Gamma knife globus pallidus interna pallidotomy was performed in two Parkinson's disease patients. A radiation dose of 130Gy(range 120-140Gy) was delivered. Patients were followed for a median of 13 months(range 9-14 months). Result : Ventrolateral thalamotomy in dystonia produced regained left hand usage in order to be able to use the telephone. Ventralis intermedius thalamotomy produced an excellent improvement of the tremor in one case, mild improvement of the tremor in the other case of Parkinson's disease. A globus pallidus internalis(GPi) pallidotomy produced improvement of rigidity and dyskinesia : one other showed no change. There were no neurological complications. Conclusion : Gamma Knife thalamotomy considered a safe and effective technique for the treatment of tremor in Parkinson's disease. Although the results from Longer follow-up is not available yet, the short-term results seem to be encouraging.

• Journal of Korean Neurosurgical Society
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• v.29 no.5
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• pp.650-658
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• 2000

Objective : To evaluate the role of Gamma Knife radiosurgery in essential and tumor-related(secondary) trigeminal neuralgia, outcomes of radiosurgery and microsurgery were compared each other. Methods : Five patients with essential trigeminal neuralgia underwent stereotactic radiosurgical treatment with Leksell Gamma Knife and twenty five patients were treated with microsurgery during the same period(1994. 1-1997. 6). A 4-mm collimator was used and REZ or proximal portion of trigeminal nerve was targeted with maximal dose of 60-72Gy. The mean follow-up after radiosurgery was 39.4 months and that after microsurgery was 47.9 months. Results : At the last follow-up, four patients(80%) had excellent(pain free) or good(50-90% pain relief) outcomes, one(20%) had poor control after radiosurgical treatment. Twenty-three patients(92%) had excellent or good outcomes and two(8%) had poor results after microsurgery. Postoperative complications occurred in ten(40%) with microsurgery, but there were no complications in patients with Gamma Knife radiosurgery. Six patients with secondary trigeminal neuralgia received radiosurgical treatment directed at their tumors, and three patients were surgically treated. Three of six(50%) patients treated with Gamma Knife had pain relief while two of three patients with surgical treatment showed immediate pain relief. Post-treatment complications were developed in two of six radiosurgical patients and in one of three surgical patients. Conclusion : Gamma Knife stereotactic radiosurgery may be considered as a useful and alternative option for the treatment of essential and secondary trigeminal neuralgia owing to of its safety and less complications. The preliminary results obtained in our series appear encouraging, although the outcome is not so good as that of surgery.

• Journal of Korean Neurosurgical Society
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• v.60 no.6
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• pp.667-675
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• 2017

Objective : Total resection without consecutive postoperative whole brain radiation therapy is indicated for patients with a single or two sites of brain metastasis, with close follow-up by serial magnetic resonance imaging (MRI). In this study, we explored the effectiveness, usefulness, and safety of this follow-up regimen. Methods : From January 2006 to December 2015, a total of 109 patients (76 males, 33 females) underwent tumor resection as the first treatment for brain metastases (97 patients with single metastases, 12 with two metastases). The mean age was 59.8 years (range 27-80). The location of the 121 tumors in the 109 patients was supratentorial (n=98) and in the cerebellum (n=23). The origin of the primary cancers was lung (n=45), breast (n=17), gastrointestinal tract (n=18), hepatobiliary system (n=8), kidney (n=7), others (n=11), and unknown origin (n=3). The 121 tumors were totally resected. Follow-up involved regular clinical and MRI assessments. Recurrence-free survival (RFS) and overall survival (OS) after tumor resection were analyzed by Kaplan-Meier methods based on clinical prognostic factors. Results : During the follow-up, MRI scans were done for 85 patients (78%) with 97 tumors. Fifty-six of the 97 tumors showed no recurrence without adjuvant local treatment, representing a numerical tumor recurrence-free rate of 57.7%. Mean and median RFS was 13.6 and 5.3 months, respectively. Kaplan-Meier analysis revealed the cerebellar location of the tumor as the only statistically significant prognostic factor related to RFS (p=0.020). Mean and median OS was 15.2 and 8.1 months, respectively. There were no significant prognostic factors related to OS. The survival rate at one year was 8.2% (9 of 109). Conclusion : With close and regular clinical and image follow-up, initial postoperative observation without prompt postoperative radiation therapy can be applied in patients of brain metastasi(e)s when both the tumor(s) are completely resected.

• Journal of Korean Neurosurgical Society
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• v.54 no.2
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• pp.107-111
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• 2013

Objective : We investigated the effectiveness of stereotactic gamma knife Radiosurgery (GKR) for radioresistant brain metastases with the impact upon histology. Methods : Between April 2004 and May 2011, a total of 23 patients underwent GKR for 67 metastatic brain tumors from 12 renal cell cancers, 5 sarcomas and 6 melanomas. The mean age was 56 years (range, 18 to 79 years). Most of the patients were classified as the Radiation Therapy Oncology Group recursive partitioning analysis class II (91.3%). The synchronous metastasis was found in 6 patients (26.1%) and metachronous metastasis in 17 patients (73.9%). We analyzed the local control rate, intracranial progression-free survival (PFS) and overall survival (OS). Results : The mean tumor volume for GKR was 2.24 cc and the mean prescription dose was 19.4 Gy (range, 10 to 24) to the tumor margin. Out of metachronous metastases, the median duration to intracranial metastasis was 3.3 years in renal cell cancer (RCC), 2.4 years in melanoma and 1.1 years in sarcoma (p=0.012). The total local control rate was 89.6% during the mean 12.4 months follow-up. The six-month and one-year local control rate was 90.2% and 83% respectively. Depending on the pathology, the control rate of RCC was 95.7%, sarcoma 91.3% and melanoma 80.5% during the follow-up. The common cause of local failure was the tumor bleeding in melanoma. The median PFS and OS were 5.2 and 8.4 months in RCC patients, 6.5 and 9.8 months in sarcoma, and 3.8 and 5.1 months in melanoma. Conclusion : The GKR can be one of the effective management options for the intracranial metastatic tumors from the radioresistant tumors. The melanoma showed a poor local control rate compared to other pathologies because of the hemorrhage.

• Progress in Medical Physics
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• v.31 no.2
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• pp.29-34
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• 2020

Purpose: The interaction of various substances inserted into the human body and radiation can confirm the radiation enhancement effect. A Leksell frame inserted into the human body for gamma knife treatment will cause not only pain and inconvenience to the patient, but also additional exposure to the patient's normal tissues. In this study, we attempt to confirm the additional exposure caused by the interaction of the Leksell frame and thermoplastic mask, and ⁶⁰Co used for gamma knife treatment. Methods: A ⁶⁰Co energy of 1.17, 1.33 MeV is applied using Monte Carlo simulation, and fixation screws and thermoplastic mask are fabricated using aluminum and titanium alloy, and Carbon compounds. Results: Results show a dose enhancement of up to 396.27% higher compared with that without a Leksell frame and up to 391.25% in thermoplastic mask. Conclusions: Hence, appropriate treatment methods and materials must be used to reduce additional exposure to normal tissues.