• Progress in Medical Physics
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• v.29 no.1
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• pp.8-15
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• 2018

This work reports the acceptance testing and commissioning experience of the Robotic Intensity-Modulated Radiation Therapy (IMRT) M6 system with a newly released $InCise^{TM}2$ Multileaf Collimator (MLC) installed at the Yonsei Cancer Center. Acceptance testing included a mechanical interdigitation test, leaf positional accuracy, leakage check, and End-to-End (E2E) tests. Beam data measurements included tissue-phantom ratios (TPRs), off-center ratios (OCRs), output factors collected at 11 field sizes (the smallest field size was $7.6mm{\times}7.7mm$ and largest field size was $115.0mm{\times}100.1mm$ at 800 mm source-to-axis distance), and open beam profiles. The beam model was verified by checking patient-specific quality assurance (QA) in four fiducial-inserted phantoms, using 10 intracranial and extracranial patient plans. All measurements for acceptance testing satisfied manufacturing specifications. Mean leaf position offsets using the Garden Fence test were found to be $0.01{\pm}0.06mm$ and $0.07{\pm}0.05mm$ for X1 and X2 leaf banks, respectively. Maximum and average leaf leakages were 0.20% and 0.18%, respectively. E2E tests for five tracking modes showed 0.26 mm (6D Skull), 0.3 mm (Fiducial), 0.26 mm (Xsight Spine), 0.62 mm (Xsight Lung), and 0.6 mm (Synchrony). TPRs, OCRs, output factors, and open beams measured under various conditions agreed with composite data provided from the manufacturer to within 2%. Patient-specific QA results were evaluated in two ways. Point dose measurements with an ion chamber were all within the 5% absolute-dose agreement, and relative-dose measurements using an array ion chamber detector all satisfied the 3%/3 mm gamma criterion for more than 90% of the measurement points. The Robotic IMRT M6 system equipped with the $InCise^{TM}2$ MLC was proven to be accurate and reliable.

• The Journal of Korean Physical Therapy
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• v.12 no.3
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• pp.349-359
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• 2000

The aim of study was to evaluated the possible role of cranial artery velocity in headache pathogenesis. The present study was studied of five headache(F=5. Mean $age=29.80\pm6.76yrs$) were compared to 4 controls(F=4, Mean $age=29.00\pm5.48yrs$). Transcranial doppler ultrasonography(TCD) is a new non-invasive and easily applicable method to evaluate flow velocities of the intracranial and extracranial cerebral arteries. TCD was performed with standard method to measure the mean Flow Velocity(MFV) of the middle and posterior cerebral arteries, the internal carotid artery, the vertebral and the basilar artery. We reviewed the whole TCD results performed at Taejon Veterans Hospital from October. 11. 2000 to November. 10. 2000. Mean flow velocities in headaches and controls at their 6 decades are $28.00\pm3.61cm/sec$ and $41.25pm1.71cm/sec$ in lent PCA (P<0.01), $50,000\pm23.07cm/sec$ and $82.75\pm15.59cm/sec$ in right MCA(P<0.05), $26.20\pm4.82cm/sec$ and $45.50\pm4.51cm/sec$ in fight PCA(P<0.01). $26.60\pm4.56cm/sec$ and $38.25\pm4.92cm/sec$ in right VAC(P<0.01). After treatment for 2 weeks, mean of velocity on pre treatment and post treatment and post treatment are $28.00\pm3.61cm/sec$ and $38.20\pm5.81cm/sec$ in left PCA (P<0.05), $26.20\pm4.827cm/sec$ and $39.20\pm5.54cm/sec$ in right PCA(P<0.05), $40.60\pm9.18cm/sec$ in right VA(P<0.01). It is concluded that Electrical Therapy for two weeks was effected to promote Mean Flow of Velocity in cranial artery. Mean of velocity in cranial artery with headaches observed in this study was lower than controls, but MFV was promote after treatment for 2 weeks.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.4
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• pp.267-274
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• 2008

Purpose: Transient neurological deterioration (TND) is one of the complications after extracranial-intracranial bypass surgery, and it has been assumed to be caused by postoperative transient hyperperfusion. This study was performed to evaluate the relationship between TND and preoperative and postoperative cerebral perfusion status on brain perfusion SPECT following superficial temporal artery - middle cerebral artery (STA-MCA) anastomosis surgery. Materials and Methods: A total of 60 STA-MCA anastomosis surgeries of 56 patients (mean age: $50{\pm}16$ yrs; M:F=29:27; atherosclerotic disease: 33, moyamoya disease: 27) which were done between September 2003 and July 2006 were enrolled. The resting cerebral perfusion and cerebral vascular reserve (CVR) after acetazolamide challenge were measured before and 10 days after surgery using 99mTc-ethylcysteinate dimer (ECD) SPECT. Moreover, the cerebral perfusion was measured on the third postoperative day. With the use of the statistical parametric mapping and probabilistic brain atlas, the counts for the middle cerebral artery (MCA) territory were calculated for each image, and statistical analyses were performed. Results: In 6 of 60 cases (10%), TND occurred after surgery. In all patients, the preoperative cerebral perfusion of affected MCA territory was significantly lower than that of contralateral side (p=0.002). The cerebral perfusion on the third and tenth day after surgery was significantly higher than preoperative cerebral perfusion (p=0.001, p=0.02). In TND patients, basal cerebral perfusion and CVR on preoperative SPECT were significantly lower than those of non-TND patients (p=0.01, p=0.05). Further, the increases in cerebral perfusion on the third day after surgery were significant higher than those in other patients (p=0.008). In patients with TND, the cerebral perfusion ratio of affected side to contralateral side on third postoperative day was significantly higher than that of other patients (p=0.002). However, there was no significant difference of the cerebral perfusion ratio on preoperative and tenth postoperative day between patients with TND and other patients. Conclusion: In patients with TND, relative and moderate hyperperfusion was observed in affected side after bypass surgery. These finding may help to understand the pathophysiology of TND.