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R W Kline

Publications and source records attributed to R W Kline.

At least 19 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↗
PubMed1984

Single and double plane implants: a comparison of the Manchester System with the Paris System.

A comparison between the Manchester System and the Paris System of interstitial dosimetry has been made in the case of single and double plane implants. The rules of both systems are reviewed. A brief description of the Paris System is presented in an appendix. Dose distributions for two different examples are presented in two orthogonal planes. The Paris System uses considerably fewer sources than the Manchester System. It results in a larger volume of high dose than the Manchester System. The use of Iridium-192 sources strength and source length can be adjusted represents a significant advantage. The Paris System attempts to adapt the implant configuration to the clinical situation as the target thickness is used to define the source separation and the target length is used to define the source length. The differences in the dose definition are discussed.

Brachytherapy↗
PubMed1984

Treatment of meningeal relapse in childhood acute lymphoblastic leukemia. I. Results of craniospinal irradiation.

Fourteen children were treated for isolated meningeal relapse occurring seven to 44 months (median, 14 months) after prophylactic cranial irradiation (2,400 rad/12 fractions) and intrathecal methotrexate (IT MTX, 12 mg/m2 for four doses during cranial irradiation). Eight had "high-risk" acute lymphocytic leukemia with age less than 2 years, white blood cell counts greater than 20,000, or T cell markers. Treatment for central nervous system leukemia included IT MTX (12 mg/m2 twice weekly until clearance of spinal fluid cytology) followed by craniospinal irradiation (CSI, 3,000 rad/20 fractions to the cranium and 1,800 rad/12 fractions to the spine). No maintenance IT MTX was given. Systemic chemotherapy was continued or reinstituted for a minimum of one year after CSI. No instance of second meningeal relapse has occurred. Five patients remain in secondary complete remission 66+, 54+, 36+, 26+, and 24+ months after meningeal relapse. Disease-free survival was limited by marrow relapse in eight patients (2-20 months after CSI) and testicular relapse in one. No acute toxicities were noted with CSI. Myelosuppression occurred in seven patients. Infections within two months of CSI were noted in five. No neurologic sequelae are apparent. Serial neuropsychometric studies in 10 patients revealed a significant decline in mean values on Global IQ scales. Long-term survival with acceptable toxicity is possible following aggressive, prompt treatment of meningeal relapse occurring after prophylactic cranial irradiation. Hematologic relapse remains the major obstacle to long-term disease-free survival.

Acute Disease↗
PubMed1983

Do prostatic biopsies 12 months or more after external irradiation for adenocarcinoma, Stage III, predict long-term survival?

Serial biopsies of the prostate after high dose external irradiation for adenocarcinoma show a gradual disappearance of the neoplastic cells. With such treatment, results of the biopsies do not have any short term prognostic significance. However, positive biopsies 12 months or more after treatment are reputed to be an unfavorable sign for long-term survival. From August, 1970 through February, 1974, 46 consecutive patients with locally advanced (Stage III, C, or T3 and T4) adenocarcinoma of the prostate underwent external irradiation with 2 MV X rays or cobalt-60 teletherapy. The technique included parallel, opposed, 14 X 14 cm anterior and posterior fields, and a 10 X 14 cm perineal field. The center of the prostate received a total dose of 70 Gy in 30-37 fractions in 43 to 56 days. Details of the dosimetry reveal inhomogeneity of the dose of +/- 7% within an enlarged prostate. With a median follow-up of 8 years, the actuarial survival rates, uncorrected for death from intercurrent disease, are 69% at 5 years and 49% at 10 years. Biopsies of the prostate 12 months or more after treatment were available from 31 patients: 19 had one or more positive biopsies and 12 had consistently negative biopsies; the survival curves are identical for those with and those without positive biopsies. Prostatic biopsies obtained 24 months or more after treatment were available from 21 patients: 10 had positive and 11 had negative biopsies; the survival curves are identical for those with and without residual cancer cells. Following adequate irradiation of patients with locally advanced adenocarcinoma of the prostate, the results of biopsies obtained one or two years after treatment do not predict long-term survival.

Adenocarcinoma↗
PubMedDate not supplied

A linear accelerator monitor unit totalizer.

An independent primary dose counter or totalizer has been developed for our linear accelerator. This counter is reset independently of the control console and thus will totalize the number of monitor units (MUs) delivered to the patient. This is especially useful for patients being treated at extended distances when it is necessary to reset the control console several times. The independent totalizer does not load down the control console dosimetry circuit and can be adapted to the digital logic used. The details of the system will be presented.

Humans↗
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↗