No abstract available.
Proton Pumps* ; Protons*

The recently developed ProTon tonometer is a small hand-held instrument which has less chances of infectious ocular diseases transmission and corneal abrasion than other types of tonometer. We compared the intraocular pressures taken by the ProTon tonometer with those by the Goldmann applanation tonometer in 290 eyes of 145 patients. The results were as follows: 1. The difference of the intraocular pressures between the ProTon tonometer and the Goldmann tonometer is less than 3mmHg in 91.03% of the estimation, and less than ImmHg in 64.83%. 2. The average intraocular pressure measured by the ProTon tonometer is lower than that by the Goldmann applanation tonometer. In the higher intraocular pressure zone, the difference of intraocular pressures between the two is more increased. 3. The correlation between the intraocular pressures measured by the ProTon tonometer and those by the Goldmann tonometer is very high(correlation coefficient 0.98). According to the above results, we conclude that the ProTon tonometer can be used more accurately and conveniently for both patient and examiner than other classic instruments.
Humans ; Intraocular Pressure ; Protons*

No abstract available.
Osteoporosis ; Proton Pumps ; Protons

No abstract available.
Craniocerebral Trauma* ; Head* ; Protons*

No abstract available.
Manometry* ; Proton Pumps* ; Protons*

The main benefit of proton therapy over photon beam radiotherapy is the absence of exit dose, which offers the opportunity for highly conformal dose distributions to target volume while simultaneously irradiating less normal tissue. For proton beam therapy two patient specific beam modifying devices are used. The aperture is used to shape the transverse extension of the proton beam to the shape of the tumor target and a patient-specific compensator attached to the block aperture when required and used to modify the beam range as required by the treatment plan for the patient. A block of range shifting material, shaped on one face in such a way that the distal end of the proton field in the patient takes the shape of the distal end of the target volume. The mechanical quality assurance of range compensator is an essential procedure to confirm the 3 dimensional patient-specific dose distributions. We proposed a new quality assurance method for range compensator based on image processing using X-ray tube of proton therapy treatment room. The depth information, boundaries of each depth of plan compensatorfile and x-ray image of compensator were analyzed and presented over 80% matching results with proposed QA program.
Humans ; Proton Therapy ; Protons

No abstract available.
Biopsy* ; Brain* ; Protons*

No abstract available.
Eosinophilia* ; Proton Pumps* ; Protons*

We studied a Monte Carlo simulation of the proton beam delivery system at the National Cancer Center (NCC) using the Geant4 Monte Carlo toolkit and tested its feasibility as a dose verification framework. The Monte Carlo technique for dose calculation methodology has been recognized as the most accurate way for understanding the dose distribution in given materials. In order to take advantage of this methodology for application to externalbeam radiotherapy, a precise modeling of the nozzle elements along with the beam delivery path and correct initial beam characteristics are mandatory. Among three different treatment modes, double/single.scattering, uniform scanning and pencil beam scanning, we have modeled and simulated the double.scattering mode for the nozzle elements, including all components and varying the time and space with the Geant4.8.2 Monte Carlo code. We have obtained simulation data that showed an excellent correlation to the measured dose distributions at a specific treatment depth. We successfully set up the Monte Carlo simulation platform for the NCC proton therapy facility. It can be adapted to the precise dosimetry for therapeutic proton beam use at the NCC. Additional Monte Carlo work for the full proton beam energy range can be performed.
Proton Therapy ; Protons* ; Radiotherapy

No abstract available.
Proton Pumps ; Protons