Dosimetric study of the narrow beams of 60Co teletherapy unit for stereotactic radiosurgery
| Autor: | Paul B Ravindran, Paul S. Nizin, Rabi Raja Singh I. M.S.a, Komanduri M Ayyangar |
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| Rok vydání: | 2000 |
| Předmět: |
Materials science
Radiological and Ultrasound Technology business.industry Radiography Penumbra medicine.medical_treatment Radiation Radiosurgery Oncology Ionization Ionization chamber medicine Humans Radiology Nuclear Medicine and imaging Cobalt-60 Cobalt Radioisotopes business Nuclear medicine Radiometry Beam (structure) |
| Zdroj: | Medical dosimetry : official journal of the American Association of Medical Dosimetrists. 25(3) |
| ISSN: | 0958-3947 |
| Popis: | This study explores the possibility of using a telecobalt unit for radiosurgery. A dosimetric study was performed for the narrow beam of Cobalt 60 (60Co) unit with circular radiation fields in diameters of 11, 17, 20, 27, 32, 35, 40, and 44 mm. Percentage depth dose and off-axis ratio were measured with ion chamber and radiographic film. The tissue air ratio values derived from measurements agreed well with the calculated values for all cone sizes and depths, ranging from the depth of maximum ionization of 24 cm in water. A quantitative evaluation of treatment plans with 60Co and 6-MV photon beams was carried out. The penumbra of the narrow beam of 60Co was larger than that of the 6-MV beam by 1.3 mm on average. This difference in penumbra can be attributed to the large source size of 60Co units. The feasibility of using narrow-beam 60Co for stereotactic radiosurgery/radiotherapy is discussed. |
| Databáze: | OpenAIRE |
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