PubMed · 1338855
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G N Ursol, L P Kondratenko, V A Luntovskiĭ, V A Davydkin, S V Grishakov, V V Lishenko, V A Starikov. 1992. [A universal clamp].. https://pubmed.ncbi.nlm.nih.gov/1338855/
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Teleotolaryngology is becoming a reality as a result of improvements in technology and telecommunications. This prospective, clinical trial was designed to demonstrate the utility of three telemedicine systems in an otolaryngology practice. Optel is a desktop system used in the office. Picasso is a mobile system used from various locations throughout the hospital. The Georgia Statewide Telemedicine Program (GSTP) is a large, sophisticated system used from a fixed site within a rural hospital. Patients with a wide variety of ear, nose, and throat problems were presented to consultants at two medical teaching centers in Georgia. Fifty-four consults were completed over a 24-month period. In addition, three teleconsultations demonstrated enhanced capabilities for continuing medical education (CME) and health care networks. Nine different specialty fields were accessed by the otolaryngologist. Five consults were completed via the Optel system; 13 via the Picasso system; and 36 via GSTP. Overall, teleotolaryngology provided quality audio and visual communication between the physicians that significantly improved diagnostic capabilities and treatment options for the patient.
PURPOSE: To deliver uniform dose distributions for total-body irradiation (TBI) with an arc field and a gravity-oriented compensator. This technique allows the patient to be treated lying on the floor in a small treatment room. METHODS AND MATERIALS: Through the sweeping motion of the gantry, a continuous arc field can deliver a large field to a patient lying on the floor. The dose profile, however, would not be uniform if no compensator were used, due to the effects of inverse square variation of beam intensity with distance as well as the slanted depth in patient. To solve this problem, a gravity-oriented compensator made of cerrobend alloy was designed. This compensator has a cross-section of an inverted isosceles triangle, with the apex always pointing downward, due to gravity. By properly selecting the thickness of the compensator, the width of the base, and the distance between the pivots to the base, the difference in the path length through the compensator can be made just right to compensate the effects of inverse-square and slanted depth, thus producing a uniform dose profile. RESULTS: Arc fields with a gravity-oriented compensator were used for 6, 10, 15, and 18 MV photon beams. The arc field can cover a patient with a height up to 180 cm. The field width was chosen from 32 to 40 cm at the machine isocenter. The optimal thickness of the compensator was found to be 2.5 cm, and its base was 25 cm wide. The distance from the pivot points to the flat surface of the compensator proximal to the beam ranges from 13 to 14 cm for different beam energies. The dose uniformity at a depth of 10 cm is within +/-5% for all beam energies used in this study. CONCLUSIONS: Highly uniform dose profiles for TBI treatments can be delivered with an arc and a gravity-oriented compensator. The proposed technique is simple and versatile. A single compensator can be used for all energies, because the amount of compensation can be adjusted by changing the distance to the pivot and/or the field size.