-
Article type: Cover
1995 Volume 51 Issue 12 Pages
Cover10-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Cover
1995 Volume 51 Issue 12 Pages
Cover11-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Index
1995 Volume 51 Issue 12 Pages
Toc7-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Index
1995 Volume 51 Issue 12 Pages
Toc8-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
[in Japanese]
Article type: Article
1995 Volume 51 Issue 12 Pages
i-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1995 Volume 51 Issue 12 Pages
ii-iv
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1995 Volume 51 Issue 12 Pages
v-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1995 Volume 51 Issue 12 Pages
vi-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1995 Volume 51 Issue 12 Pages
vii-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1995 Volume 51 Issue 12 Pages
viii-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
KEN-ICHI YOSHIDA, SADAMITSU NISHIHARA, HIROMI NAGANO, KEIKO OHMURA, KA ...
Article type: Article
1995 Volume 51 Issue 12 Pages
1737-1741
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
It is thought that noise property and the shape of H-D curve of AD system (HGM/URI) are more suited for chest radiographs compared with conventional system (HR4/super HRS). Therefore, we studied the visual detectability of low contrast simulated nodules using chest radiographs taken by AD and HR4/super HRS systems. Film base was used as a simulated nodule. Fifty-six radiographs, with and without a nodule each, were employed for ovserber performance test. Reciever operating characteristic analysis (the method for continuously-distributed test results) was used for observer performance data. As a result, the total detectability of AD system was slightly superior to that of HR4/super HRS system. In the mediastinum area, however, AD system was greatly superior compared to HR4/super HRS system, and in the lung field both were almost equal.
View full abstract
-
HIROMI NAGANO, SADAMITSU NISHIHARA, KEN-ICHI YOSHIDA, KEIKO OHMURA, KA ...
Article type: Article
1995 Volume 51 Issue 12 Pages
1742-1746
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
We studied the characteristics of a new screen/film system (AD system : HGM/UR-1, Fuji) for chest radiography, that is, H-D curve, relative speed, cross-over effect, resolution and noise properties, X-ray attenuation rate and relative fluorescence. The shape of characteristic curve of UR-1 film is suitable for chest radiography, because the density of UR-1 is higher than that of super HRS film (sHRS) in low exposure range. However, the film gradient of UR-1 is a little lower compared to sHRS. The visibility of mediastnum area and lungs by AD system is superior and or equivalent, compared with conventional HR4 screen/sHRS film system. Relative speed of UR-1 film was approximately 50% sHRS. However, the speed of AD system was equivalent to HR4/s HRS system. Cross-over ratio of UR-1 film was 30% lower than that of sHRS film. X-ray attenuation rate and relative fluorescence of HGM screen were 15% and 120% higher than these of HR4, respectively. Modulation transfer function of AD system and HR4/sHRS system were equivalent. Wiener Spectral value of AD system was 50% lower than that of HR4/sHRS system in low spatial frequency, and 20% lower in high spatial frequency.
View full abstract
-
IKUO IKEDA, HIROMI IKEZAKI, NAOMOTO MATSUMOTO, KAZUYUKI KOMATSU, TOSHI ...
Article type: Article
1995 Volume 51 Issue 12 Pages
1747-1750
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
Field factor (F_A) for a small field is able to be obtained by film dosimetry with conception of monitor unit (MU) which provides constant density. Close agreement between F_A measured by film dosimetry and F_A measured by the ionization chamber and the semiconductor detector, could be obtained. In this method, F_A is able to be measured without converting film density into an irradiated dose. This method could also be applied to the measurement of F_A for infinitesimally small irradiated fields.
View full abstract
-
TAKASHI OGINO
Article type: Article
1995 Volume 51 Issue 12 Pages
1751-1755
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
The methods for determining the margin of a radiation field using the opposed two fields irradiation technique are evaluated. Conventionally, the prescribed distance of the margin is determined by only one side projection of the two ports (method A). There is another method in which the gantry is rotated to the other side and the margins are determined for both sides projection (method B). Differences in the irradiated volumes are analyzed using a dose-volume histogram between method A and B. In the target, irradiated volumes of the 100% dose range are not significantly different for either method. In the phantom, however, irradiated volumes of each dose range differ according to the location of target by method A. In contrast, those in method B are not changed. It is considered that taking the exact distance from the target as a margin is theoretically acceptable for determining the size of the field.
View full abstract
-
TADASHI MISHIRO
Article type: Article
1995 Volume 51 Issue 12 Pages
1756-1762
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
YUKIO UCHIYAMA
Article type: Article
1995 Volume 51 Issue 12 Pages
1763-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
TAKESHI HIRAOKA, KANAME OMATA, AKIFUMI FUKUMURA, TORAJI IRIFUNE, HIROK ...
Article type: Article
1995 Volume 51 Issue 12 Pages
1764-1769
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
With the increasing use of the linear accelerators for photon beam radiosurgery, it has become fairly difficult to obtain a precise determination of absorbed dose and dose distribution because of the failure of the secondary electron equilibrium in the lateral direction for such a small fields. To investigate the dosimetry method for very small fields, several different types and sized of detectors have been used for the measurements of high energy photon Beams. The detectors used in this experiment consisted of five ionization chambers, four silicon diodes and a diamond detector. For the measurement of the lateral dose distributions, the size of the detector is the most important factor for determining the dose. However, the size is not so important for the measurement of the depth dose distributions, because the OCR curve is only slightly different regarding the depth for small fields. We suggest that the dose should be determined through the use of combination of several small detectors for nattow beam dosimetry.
View full abstract
-
MITSUNORI KONNO, HIROSHI KABE, HISATAKA HAYASHI, MORIAKI SHUTOH, KAZUT ...
Article type: Article
1995 Volume 51 Issue 12 Pages
1769-1773
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
Recently, stereotactic radiosurgery has been implemented not only with GammaKnife but also with linear accelerators. Stereotactic multiple arc radiotherapy (SMART) has been conducted mainly for small solitary metastatic brain tumor with linear accelerator 6-MV X-ray beams in Department of Radiation Oncology, National Cancer Center Hospital since 1991. Fractionated radiation is mandatory in SMART due to the nature of the tumor, and practicability in reproducible positioning and immobilization of the patient is of utmost importance. A special cast fixed with the mouthpiece is designed to apply for each patient, and by using the cast together with the pillow, practically feasible accuracy in positioning is assured, without the invasive frame. As to the cast material, meshed one is not suitable for marking the points of 3-dimensional coordinates because of the scattered holes, and we use "Thermoshell" without holes. Procedure of the SMART therapy and detailed process of manufacturing the special cast are presented and the accuracy of positioning and reproducibility in fractionation together with precision of the machine and related equipments are mentioned.
View full abstract
-
TETSUZO NARA, YOSHIAKI HORANAI, TADATOH OYAMA, HIROJI SUTOH, TADASHI S ...
Article type: Article
1995 Volume 51 Issue 12 Pages
1773-1781
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
By examining the accuracy of the 4-and 10-MV X-ray narrow beam dose calculation results performed using a 3-D radiation treatment planning system called FOCUS, we could obtain the following results : 1) A slice thickness of 5mm was effectively satisfied for non-corplanar beams. 2) The phantom scatter correction factor should be used accurately when making the tissue-phantom ratio from the percentage depth dose. 3) The calculation algorism employs the Clarkson method, which is very time consuming. The ratio TAR method and others, which are not so time consuming as the Clarkson method, should be utilized.
View full abstract
-
KAZUFUSA SHOJI, YOSHIHITO NOMOTO, KANN TAKEDA, TSUYOSHI NAKAGAWA, KOUI ...
Article type: Article
1995 Volume 51 Issue 12 Pages
1782-1786
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
In stereotactic radiosurgery, as a one form of the conformal radiotherapy, target dose is higher and normal tissue dose is lower than conventional radiotherapy. This make it possible to achive excellent local control and few normal tissue conplication. Now Linac radiosurgery is spreading in Japan. Current problems in Linac radiosurgery is as follows. Problems about patients are indications of radiosurgery to various lesions, and now this is still controversial. Problems about technical aspect are 1) treatment of irregular shaped lesions, 2) quality assurance of isocenter position and irradiate dose and 3) evaluation of treatment plans and TCP, NTCP analyses. In our hospital stereotactic radiosurgery was started in Nov 1994. Our experience is showed briefly.
View full abstract
-
YOSHIHARU WATANABE
Article type: Article
1995 Volume 51 Issue 12 Pages
1786-1788
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
NOBORU MATSUNAGA
Article type: Article
1995 Volume 51 Issue 12 Pages
1788-1791
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
YUKIO UCHIYAMA
Article type: Article
1995 Volume 51 Issue 12 Pages
1791-1792
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
TEIZOU TOMARU
Article type: Article
1995 Volume 51 Issue 12 Pages
1793-1797
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
KEIGO ENDOH
Article type: Article
1995 Volume 51 Issue 12 Pages
1798-1802
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
MASAAKI KODAMA
Article type: Article
1995 Volume 51 Issue 12 Pages
1803-1805
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
MASASHI MATSUZAKI
Article type: Article
1995 Volume 51 Issue 12 Pages
1805-1807
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
RYOICHI TANAKA
Article type: Article
1995 Volume 51 Issue 12 Pages
1807-1809
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
YOSHIO ISHIDA
Article type: Article
1995 Volume 51 Issue 12 Pages
1809-1812
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
Article type: Article
1995 Volume 51 Issue 12 Pages
1813-1825
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1995 Volume 51 Issue 12 Pages
1826-1827
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1995 Volume 51 Issue 12 Pages
1828-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1995 Volume 51 Issue 12 Pages
1829-1836
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Appendix
1995 Volume 51 Issue 12 Pages
1837-1838
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Bibliography
1995 Volume 51 Issue 12 Pages
1839-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Index
1995 Volume 51 Issue 12 Pages
1840-1845
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Index
1995 Volume 51 Issue 12 Pages
1846-1850
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS
-
Article type: Cover
1995 Volume 51 Issue 12 Pages
Cover12-
Published: December 01, 1995
Released on J-STAGE: June 29, 2017
JOURNAL
FREE ACCESS