All issues
Volume 27 (1971)
- Issue 5 Pages 414-
- Issue 4 Pages 321-
- Issue 3 Pages 180-
- Issue 2 Pages 92-
- Issue 1 Pages 1-
Volume 27, Issue 3
Displaying 1-16 of 16 articles from this issue
- |<
- <
- 1
- >
- >|
-
Article type: Cover
1971 Volume 27 Issue 3 Pages Cover7-
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSDownload PDF (587K) -
Article type: Cover
1971 Volume 27 Issue 3 Pages Cover8-
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSDownload PDF (587K) -
Article type: Appendix
1971 Volume 27 Issue 3 Pages App4-
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSDownload PDF (465K) -
[in Japanese]Article type: Article
1971 Volume 27 Issue 3 Pages 180-204
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSDownload PDF (5503K) -
Shusaku MatsukawaArticle type: Article
1971 Volume 27 Issue 3 Pages 205-216
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSComputer processing of radiotherapy planning are now going to be a routine work in major radiotherapy departments. The author reviewed the algorithm for dose computation. These treatmentplanning work should be integrated into the hospital medical information processing system National Cancer Center Radiotherapy System which have been developed by the author and his colleagues is to be introduced in this paper.View full abstractDownload PDF (1393K) -
YOSHINOBU NAKADA, SHIGERU SOMAZAWAArticle type: Article
1971 Volume 27 Issue 3 Pages 217-225
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSTte distribution of the radiation dose within a uniform, circular, 'Phantom' column (30cm. in diameter) was measured in terms of the eccentric angle, θ, between the zero axis of the column and the central axis of the eccentric beam, for the point P' which lies at the same distance, n, from the source as does the center of rotation of the 'Phantom', at a distance γ from the center of rotation (taken as the eccentric radius from the center of rotation of the section of the beam passing through P'). In the calculations, the 100% reference level was taken to be that at the point P, a distance equal to the eccentric radius along the zero axis of the 'Phantom' in the direction of the source. Gregory's method was applied to calculation at intervals ^o_ff 10 degrees. The absolute radiation dose, Dp, at the datum point P can be expressed theoretically by the ollowing formulas. [numerical formula] R : the angle of beam rotation T_R : the time required to rotate the beam R degrees [numerical formula] (W : width of the rotation field) In these formulas, TAR means the values of the distance P'Q from a point P' to the surface of the 'Phantom' along the eccentric beam, and it can be obtained from the following expression : [numerical formula] PR : radius of the 'Phantom' The difference between the values obtained from this formula and practical measuremets in a 28cm. diameter Mix Dp- 'Phantom' was within ± 4%.View full abstractDownload PDF (972K) -
Yoshinobu MoriArticle type: Article
1971 Volume 27 Issue 3 Pages 226-239
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSWhen the film is placed within a phantom for dosimetry purpose, the date is influenced by energy of the beam, method of the development, and the nature of emulsion. These problems were examined and the following results were obtained. 1. The error by energy dependence is negligible in measurement of low energy X-Rays and high energy electrons. In the ^<60>Co gamma Rays, the response of the correlate well with the dose measured by the ionization chamber, by reducing the thickness of phantom placed on both sides of the film. 2. Development by Automatic Processor is accurate enough for practical use. 3. The industrial film usually shows excellent linearity to exposure dose, but the response is too high for this purpose. Gravura or Ritho film has a suitable the response, but the dose-density response curve is unlinear and is influenced by developing condition.View full abstractDownload PDF (1465K) -
Sho WakuiArticle type: Article
1971 Volume 27 Issue 3 Pages 240-248
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSThe presence of tissues of different composition or density, such as bone, lung and air cavity, influences the dose distribution. The distortion of dose distribution depends on the quality of thd radiation, the size of the field, and the size and composition of heterogeneities. For cobalt 60 gamma rays and 4 MV x rays, corrections are negligible for the reduction of the dose due to the interposition of bone and due to the lack of dose build-up beyond an air cavity in cavity in clinical practice. In this parer, the methods of calculation of the dose distribution in the treatment of thoracic lesions with cobalt 60 gamma rays and 4.3 MV x rays used in the Cancer Institute Hospital are described. (1) From transverse tomographs and radiographic transit dose measurements, it is possible to determine the thickness and density of the lung and the water equivalent thickness of body to be traversed by each pencil of the beam considered. (2) When the density and thickness of lung in the pass of the beam are determnied, radiation dosage can readily be calculated at any point in the thoracic section by the following correction method. The correction factor (that is, actual/water phantom dose) can be expressed as [numerical formual] where S is the scatter correction factor, μe is the effective absorption coefficient in water, l is the passed thickness of the air-filled lung, and ρ is the average density of the air-filled lung. In general, the scatter correction factor S may be expressed as [numerical formual] where t is the depth in water-equivalent tissue beyond the lung. When t =0,k=C and when t>0,k is unity. B and C are given by B=0.138-0.243ρ+0.105ρ^2 C=0.975+0.016ρ-0.086ρ^2 The effective absorption coefficient can be expressed as μe=0.0656-0.011 logA where A is the field size at the surface. (3) For a mediastinal lesion treated with any angle of rotation and for a tumor locatea in the lung treated with rotation greater than 240 degrees, the effect of lung on the overall treatment plan may be neglected for clinical purposes, provided the absolute dose at the center of rotation is corrected for the presence of lung tissue.View full abstractDownload PDF (909K) -
Shusaku Matsukawa, YOSHINOBU NAKADA, Yoshinobu Mori, Sho Wakui, [in Ja ...Article type: Article
1971 Volume 27 Issue 3 Pages 249-250
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSDownload PDF (277K) -
Tadoru Koga, Osamu Tujiwara, Syonosuke Hide, Todomu NodaArticle type: Article
1971 Volume 27 Issue 3 Pages 251-254
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSTo take a good radiograph of the ankle at anteroposterior position, we studied about following three methods. 1) Vertical position method ; Laying flat with the toes straiting up, passed central x ray through the center of the talotibial joint. 2) 10 degrees invert position method ; Inverting the foot approximately 10 degrees, passed central x ray thro ugh vertically the center of the ankle joint. 3) Our method ; Inverting the foot untill med. malleolus and lat. malleolus become equal distance from the film, passed central x ray with angles of 7.5 degrees from vertical line through the center of the ankle joint. Studing these three methods, we concluded the last way was the best.View full abstractDownload PDF (502K) -
SHOKO OIKAWAArticle type: Article
1971 Volume 27 Issue 3 Pages 255-262
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSElectron rays of the betatron, because of their easier conversion of energy and better reproducibility as compared with those of the linear accelerator, have come to be used frequently for therapy of superficial tumors these years. The betatron today, however, has a defect that a large sized radiation field is not obtainable with its electron beam, this defect proves in most cases an obstacle to actuat treatment. The radiation port of the betatron, therefore, was widened for enlargement of the beam width and furthermore the beam was diffused with a scattering foil so as to obtain a wide dose distribution. As a result, an approximately uniform radiation was obtainable with a cone of 15cm×15cm at electron energy of 14 MeV, whereas the dose distribution result obtained at 7 or 10 MeV was a little worse than obtained at 14 Me V. In the meantime, the output intensity obtained was 90 rad/min at 7 MeV, 114 rad/min at 10 MeV and 114 rad/min at 14 MeV ; nearly instantaneous radiation was possible. The largest advantage of this modification is that the radiation field can be enlarged witheout losing the output intensity as in the case of pencil beam scanning method.View full abstractDownload PDF (1193K) -
Tadashige MakinoArticle type: Article
1971 Volume 27 Issue 3 Pages 263-265
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSIn the previous papers, the best conditions to take photograph at the differnt positions were conside red to follow the 1/r^2 rule, and the correction factor to the distance r was not described. In this paper, the latter correction factor to the absoption coefficient μ is reported, measuring at three different positions using the same phantoms. The μ-values are linear to log r. The correction factor ηr to the μ-values is deduced from this relation. Then, the best photographic condi-tion is determined using μ'=μη_r, where μ is the absor p-tion coefficient calculated from the formula reported previously.View full abstractDownload PDF (327K) -
[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...Article type: Article
1971 Volume 27 Issue 3 Pages 266-277
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSDownload PDF (1498K) -
Article type: Appendix
1971 Volume 27 Issue 3 Pages 278-315
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSDownload PDF (3253K) -
Article type: Appendix
1971 Volume 27 Issue 3 Pages 316-320
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSDownload PDF (561K) -
Article type: Cover
1971 Volume 27 Issue 3 Pages Cover9-
Published: October 31, 1971
Released on J-STAGE: June 25, 2017
JOURNAL FREE ACCESSDownload PDF (674K)
- |<
- <
- 1
- >
- >|