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M R Goede

Publications and source records attributed to M R Goede.

5 recordsLinked to original sources
PubMed1996

An analysis of the elements essential in the development of a customized TBI program.

Bone marrow transplant, once a procedure carried out at a relatively small number of large medical centers, is being employed at an increasing number of non-academic hospitals. The use of total body photon irradiation for the purpose of marrow ablation and immunosuppression can be expected to accompany the outward growth of bone marrow transplantation at these same hospitals. An analysis of the fundamental physical factors associated with total body photon irradiation (TBI) should be of value to facilities considering the incorporation of a total body irradiation program into an existing radiation oncology department. By examining the existing resources of a radiotherapy center and the clinical objectives of the treatment, a facility considering TBI may determine whether or not their center already fulfills the necessary criteria, in addition to the avoidance of potential pitfalls in project implementation.

Bone Marrow Purging↗
PubMed1992

Estimation of the mean effective organ doses for total body irradiation from Rando phantom measurements.

For the total body irradiation (TBI) procedure, it is necessary to compare the mean dose obtained from the tissue or organs and the estimated dose equivalent value from the computer program. Due to the easy-access of the Rando phantom and repeatability of TLDs and its output, the results from the experiment are quite encouraging for the verification of the dose distributions from total body irradiation at the given prescribed monitor units. The estimation of effective dose equivalent particularly across the lung sections was studied by combinations of using arms as the scatter volume to compensate for the inhomogeneity across the breast portion, as well as using the spoiler for skin-sparing purposes. The results were based upon various beam quality such as 4 MV, 6 MV, and 10 MV X rays. One series of experiments performed for this survey to ascertain the dose equivalent of the tissues was conducted. This paper describes the method and procedure for comparison between the measured data and computed data as a reference in the dosimetry of total body irradiation. Comparison of the measured and computed data for the largest collimated field shows that the calculated dose rates do not differ by more than 2% from the measured data. Because uncertainty is inherent in non-patient-like phantoms, the calculated data may be served as a reference for the dosimetry. For the total body irradiation setup, considering the radiation field size and treatment distances commonly employed, we conclude that the best combination of the patient setup will be (1) laying both arms down as compensation for lung inhomogeneity, and (2) the spoiler, which is made of acrylic about 8 mm thick and functions like a bolus, is needed to reduce the skin sparing effects and contribute the uniform dose distribution. The beam spoiler with the frame stands near the patient during the treatment.

Humans↗
PubMed1976

Central axis depth dose for a 2.5 MV Van de Graaff generator.

Central axis percentage depth dose values and isodose curves for the bremsstrahlung beam from a 2.5 MV Van de Graaff generator were measured with a water phantom at 100 cm target-to-surface distance. Tissue-air ratios were calculated from the central axis depth dose data. Use of the 2.5 MV percentage depth dose values are necessary for treatment planning since they are substantially larger than the values given in compilations for 2.0 MV beams.

Humans↗
PubMedDate not supplied

Corrections to megavoltage depth-dose values due to reduced backscatter thickness.

Multiplicative corrections for percent depth-dose values were measured for situations with nonmaximal backscatter because of reduced thickness of the irradiated phantom. Data were obtained for common clinical field sizes for a 60Co beam as well as beams from a 2.5-MV and a 4.0 MV generator. Functional forms, which summarize the results and include field size effects, depth, and thickness of the backscatter medium as variables, were obtained by regression analysis.

Cobalt Radioisotopes↗