COBALT 60 KILOCURIE TELETHERAPY ADVANTAGES AND LIMITATIONS--TECHNICAL PROBLEMS
The advantages of Co/sup 60/ therapy over conventional x-ray therapy, stemming from the fact that in the lst instance energy absorption within the tissues is by the Compton effect and in the 2nd case by the photoelectric effect, are: (1) increased skin tolerance, (2) reduced bone absorption, (3) increase in depth dose, (4) diminished radiation sickness, and (5) simplicity of operation. As a disadvantage, possibility of injury to adjacent organs is greater with Co/ sup 60/ therapy, since skin reactions, indicative of overdosage with x-ray therapy, may be absent. Some tumors at limited skin depth, such as in the larynx, are not amenable to Co/sup 60/ therapy because of the high exit dose. Various technical problems of Co/sup 60/ therapy are discussed, including precise localization of the tumor, calculation of dosage, use of filters to evenly distribute radiation and prevent hot spots, immobilization and positioning of the patient, and direct dosimetry for affirmation of calculated dosage. Favorable results are described in patients with urinary bladder tumors administered l50- to 200-rad daily doses, for a total of 6000 to 8000 rads over 6 to 8 weeks. (H.H.D.)
- Research Organization:
- Inst. Portugues de Oncologia, Lisbon
- NSA Number:
- NSA-17-000027
- OSTI ID:
- 4798191
- Journal Information:
- Arquiv. Patol. (Lisbon), Journal Name: Arquiv. Patol. (Lisbon) Vol. Vol: 33
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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