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R W Kline

Publications and source records attributed to R W Kline.

12 recordsLinked to original sources
PubMed1989

Electron beam port films.

Portal localization films are taken in order to assure the accurate placement of the treatment field relative to the patient anatomy. This is routinely done for photon fields and maybe for electron fields. This paper describes a technique which uses the bremsstrahlung component of an electron beam of energy 10 MeV and greater to expose a film to image a treatment port. These films provide verification of the placement of the electron field and document the treatment of a specific area.

Electrons↗
PubMed1986

Dose distribution in total skin electron beam irradiation using the six-field technique.

Total skin low energy electron beam irradiation is used to treat superficially widespread skin lesions such as cutaneous T-cell lymphoma. Total skin irradiation involves delivering an adequate dose at a depth of 0.25 to 1.0 cm, while sparing underlying tissue. The dose distributions obtained when using a modified Stanford six-field technique depend upon the beam energy, the beam angle, the diameter and shape of the body part, and other variables. The dose distribution uniformity of six pairs of angulated electron beams has been studied as a function of beam energy, the gantry angle, +/- theta, above and below the horizontal and the diameter of a cylindrical polystyrene phantom. Depth doses and dose uniformity for single and multiple fields have been measured as a function of beam energy, phantom diameter and position.

Electrons↗
PubMed1985

Correlation of treatment volume with milligram-hours for intracavitary applications for carcinoma of the cervix.

Following the recommendations of the European Curietherapy Group, the three-dimensional dose distribution corresponding to various milligram-hour volumes has been analyzed according to its length, width, and height dimensions. Thus, it is possible to state the dimensions of a number of isodose surfaces for a dose prescription given in milligram-hours. Problems associated with the exact placement of the three-dimensional dose distribution in relation to the patient's anatomy are discussed.

Brachytherapy↗
PubMedDate not supplied

Computer dosimetry of 192Ir wire.

The dosimetry of 192Ir linear sources with a commercial treatment planning computer system has been evaluated. Reference dose rate data were selected from the literature and normalized in a manner consistent with our clinical and dosimetric terminology. The results of the computer calculations are compared to the reference data and good agreement is shown at distances within about 7 cm from a linear source. The methodology of translating source calibration in terms of exposure rate for use in the treatment planning computer is developed. This may be useful as a practical guideline for users of similar computer calculation programs for iridium as well as other sources.

Brachytherapy↗
PubMedDate not supplied

The effect of thickness of the waterproofing sheath on the calibration of photon and electron beams.

The TG-21 protocol recommends using a thin sheath for waterproofing an ion chamber used in the calibration of photon and electron beams. A thickness of 0.5 mm is suggested for a material having a composition and density close to that of water. This work investigates the effect on the calibration of photon beams ranging from Co60 to 25 MV, and electron beams ranging from nominal energies of 7-18 MeV, for changes in the thickness of the waterproofing sheath from 0.5 to 5.5 mm. For photon beams, a maximum change of 1.2% was found for the 25-MV x-ray beam. For electron beams, a maximum change of 0.5% was found for 10-MeV electrons. It is concluded that the thickness of the waterproofing sheath is not a very sensitive variable, assuming the thickness is between 0.5 and 2.0 mm.

Calibration↗
PubMedDate not supplied

Film dosimetry of small electron beams for routine radiotherapy planning.

The characteristics of very small fields, 1 X 1 and 2 X 2 cm, of electron beams of nominal energies, 5, 7, 10, 12, 15, and 18 MeV have been studied and compared to a 10 X 10 cm field. A parallel-plate ion chamber and film have been used to obtain various dose parameters. The central axis depth dose measurements, field flatness, uniformity index, and relative output factors are presented. It was found that satisfactory results for determining the relative output factor can be obtained from film data using a scanning densitometer. It is our conclusion that film dosimetry is acceptable in determining the necessary clinical parameters needed to treat patients with fields as small as 2 X 2 cm. For the 1 X 1 cm field size and for the electron energies greater than 10 MeV, there was substantial disagreement between the ion chamber and film data in the buildup region as well as the regions beyond the depth of maximum dose to the depth of 90% dose.

Electrons↗
PubMedDate not supplied

Comparison of measured and calculated dose distributions around an iridium-192 wire.

The relative dose distribution around a 5.0-cm-long piece of 192Ir wire has been measured using LiF chips. Measurements were made at distances of 0.25 to 5.0 cm away from the source and distances of 0.0 to 4.0 cm along the source. In addition, measurements were also made at several distances along the axis of the source. Attention was paid to the errors associated with these measurements. A comparison was made between a commercial software program, ISODOS, an analytical solution to the Sievert integral, and the measurements. Good agreement was obtained at distances along and away from the source. Major disagreements were found at points along the source axis.

Humans↗
PubMedDate not supplied

The generalized geometry of eye plaque therapy.

A calculation is described that enables the rapid assessment of dose rate at various points of interest within the eye (lens, optic nerve, etc.) for the treatment of choroidal melanoma by plaque therapy. 125I seeds are used as the radiation source. The location of the plaque and its associated seeds relative to the eye (in a Cartesian coordinate system) is determined from the description of the tumor, as drawn and dimensioned on a fundus-view diagram by the ophthalmologist. This requires a computer to numerically solve an equation, which is derived in the framework of spherical geometry. Further results of this calculation yield data files that serve as the input to a conventional brachytherapy treatment planning program. This enables the visualization of the dose distribution within a plane that contains the major axis of the tumor in order to assess the adequacy of the treated volume.

Brachytherapy↗